Control Of Nitrogen Fixation In Rhizobia That Associate With Cereals

Abstract

Disclosed herein are engineered rhizobia having nif clusters that enable the fixation of nitrogen under free-living conditions, as well as ammonium and oxygen tolerant nitrogen fixation under free-living conditions. Also provided are methods for producing nitrogen for consumption by a cereal crop using these engineered rhizobia.

Description

RELATED APPLICATIONS

[0001] This application is a national stage filing under 35 U.S.C. .sctn. 371 of International Patent Application Number PCT/US2020/023646, filed Mar. 19, 2020, which claims priority under 35 U.S.C. .sctn. 119(e) to U.S. Provisional Application Ser. No. 62/820,765, filed Mar. 19, 2019 and under 35 U.S.C. .sctn. 120 of U.S. application Ser. No. 16/746,215, filed on Jan. 17, 2020, the entire contents of each of which are incorporated by reference herein.

BACKGROUND OF THE INVENTION

[0003] In agriculture, nitrogen is a limiting nutrient that needs to be added as fertilizer to those crops that cannot produce it on their own, including the cereals rice, corn, and wheat. In contrast, legumes are able to obtain nitrogen from the atmosphere using nitrogen-fixing bacteria that reside in root nodules. However, the majority of the world's calories are from cereals; thus, it has been a longstanding problem in genetic engineering to transfer this ability to these crops. This would reduce the need for nitrogenous fertilizer and the economic, environmental, and energy burdens that it brings.

SUMMARY OF THE INVENTION

[0004] The present disclosure is based, at least in part, rhizobia and methods for making rhizobia that can fix nitrogen under aerobic free-living conditions. The present disclosure also provides refactored nif-clusters that confer the ability to fix nitrogen under aerobic free-living conditions.

[0005] Accordingly, one aspect of the present disclosure provides a rhizobium that can fix nitrogen under aerobic free-living conditions, comprising a symbiotic rhizobium having an exogenous nif cluster, wherein the exogenous nif cluster confers nitrogen fixation capability on the symbiotic rhizobium under aerobic free-living conditions, and wherein the rhizobium is not Azorhizobium caulinodans. In some embodiments, the exogenous nif cluster is from a free-living diazotroph. In some embodiments, the exogenous nif cluster is from a symbiotic diazotroph. In some embodiments, the exogenous nif cluster is from a photosynthetic Alphaproteobacteria. In some embodiments, the exogenous nif cluster is from a Gammaproteobacteria. In some embodiments, the exogenous nif cluster is from a cyanobacteria. In some embodiments, the exogenous nif cluster is from a firmicutes. In some embodiments, the exogenous nif cluster is from Rhodobacter sphaeroides. In some embodiments, the exogenous nif cluster is from Rhodopseudomonas palustris. In some embodiments, the exogenous nif cluster is an inducible refactored nif cluster. In some embodiments, the inducible refactored nif cluster is an inducible refactored Klebsiella nif cluster. In some embodiments, the rhizobium is IRBG74. In some embodiments, the exogenous nif cluster comprises 6 nif genes. In some embodiments, the 6 nif genes are nifHDK(T)Y, nifEN(X), nifJ, nifBQ, nifF, and nifUSVWZM. In some embodiments, each nif gene of the exogenous nif cluster is preceded by a T7 promoter. In some embodiments, the T7 promoter is a wild-type promoter. In some embodiments, the rhizobium further comprises an endogenous nif cluster. In some embodiments, the nif cluster has a nifV gene. In some embodiments, the nifV gene is endogenous. In some embodiments, the exogenous nif cluster further comprises a terminator. In some embodiments, the T7 promoter has a terminator and the terminator is downstream from the T7 promoter. In some embodiments, the exogenous nif cluster is a refactored v3.2 nif cluster as shown in FIG. 2H.

[0006] Another aspect of the present disclosure provides a plant growth promoting bacterium that can fix nitrogen under aerobic free-living conditions, comprising a bacterium having an exogenous nif cluster having at least one inducible promoter, wherein the exogenous nif cluster confers nitrogen fixation capability on the bacterium, under aerobic free-living conditions, and wherein the bacterium is not Azorhizobium caulinodans. In some embodiments, the bacterium is a symbiotic bacterium. In some embodiments, the bacterium is an endophyte. In some embodiments, the endophyte is rhizobium IRBG74. In some embodiments, the bacterium is an epiphyte. In some embodiments, the epiphyte is Pseudomonas protogens PF-5. In some embodiments, the plant growth promoting bacterium is associated with a genetically modified cereal plant. In some embodiments, the genetically modified cereal plant includes an exogenous gene encoding a chemical signal. In some embodiments, the nitrogen fixation is under the control of the chemical signal. In some embodiments, the chemical signal is an opine (e.g., octopine, nopaine, or mannopine), phlorogluconol or rhizopene. In some embodiments, the exogenous nif cluster comprises 6 nif genes. In some embodiments, the 6 nif genes are nifHDK(T)Y, nifEN(X), nifJ, nifBQ, nifF, and nifUSVWZM. In some embodiments, the inducible promoter is a T7 promoter. In some embodiments, the inducible promoter is P.sub.A1lacO1 promoter. In some embodiments, the inducible promoter is activated by an agent selected from a group that includes IPTG, sodium salicylate, octapine, nopaline, the quorum signal 3OC6HSL, aTc, cuminic acid, DAPG, and salicylic acid. In some embodiments, the exogenous nif cluster further comprises a terminator. In some embodiments, the inducible promoter has a terminator and the terminator is downstream from the inducible promoter.

[0007] Another aspect of the present disclosure provides an Azorhizobium caulinodans capable of inducible ammonium-independent nitrogen fixation in a cereal crop, comprising: (i) a modified nif cluster, wherein an endogenous nifA gene is deleted or altered; and (ii) at least one operon comprising nifA and RNA polymerase sigma factor (RpoN), wherein the operon comprises a regulatory element including an inducible promoter. In some embodiments, the inducible promoter is P.sub.A1lacO1 promotor. In some embodiments, the inducible promoter is activated by an agent selected from the group consisting of IPTG, sodium salicylate, octapine, nopaline, the quorum signal 3OC6HSL, aTc, cuminic acid, DAPG, and salicylic acid. In some embodiments, the endogenous nifA gene is altered with at least one of the following substitutions: (i) L94Q, (ii) D95Q, and (iii) both L94Q and D95Q.

[0008] Another aspect of the present disclosure provides a method of engineering a rhizobium that can fix nitrogen under aerobic free-living conditions, comprising transferring an exogenous nif cluster to a symbiotic rhizobium, wherein the exogenous nif cluster confers nitrogen fixation capability on the symbiotic rhizobium, under aerobic free-living conditions, and wherein the rhizobium is not Azorhizobium caulinodans. In some embodiments, the exogenous nif cluster comprises 6 nif genes. In some embodiments, the 6 nif genes are nifHDK(T)Y, nifEN(X), nifJ, nifF and nifUSVWZM. In some embodiments, each of the nif genes is preceded by a wild-type T7 promoter. In some embodiments, the exogenous nif cluster is transferred to the rhizobium in a plasmid. In some embodiments, the exogenous nif cluster further comprises a terminator. In some embodiments, the wild-type T7 promoter has a terminator, and the terminator is downstream from the wild-type T7 promoter. In some embodiments, the endogenous NifL gene is deleted.

[0009] Another aspect of the present disclosure provides a method of producing nitrogen for consumption by a cereal plant, comprising providing a plant growth promoting bacterium that can fix nitrogen under aerobic free-living conditions in proximity of the cereal plant, wherein the plant growth promoting bacterium is a symbiotic bacterium having an exogenous nif cluster, wherein the exogenous nif cluster confers nitrogen fixation capability on the symbiotic bacterium, enabling nitrogen fixation under aerobic free-living conditions. In some embodiments, the plant growth promoting bacterium is a rhizobium. In some embodiments, the plant growth bacterium is a bacterium as described in the present disclosure. In some embodiments, the cereal plant is a genetically modified cereal plant. In some embodiments, the genetically modified cereal plant includes an exogenous gene encoding a chemical signal. In some embodiments, the nitrogen fixation is under the control of the chemical signal. In some embodiments, the chemical signal is opine, phlorogluconol or rhizopene. In some embodiments, the nitrogen fixation is under the control of a chemical signal. In some embodiments, the chemical signal is a root exudate, biocontrol agent or phytohormone. In some embodiments, the root exudate is selected from the group consisting of sugars, hormones, flavonoids, and antimicrobials. In some embodiments, the chemical signal is vanillate. In some embodiments, the chemical signal is IPTG, aTc, cuminic acid, DAPG, and salicylic acid, 3,4-dihydroxybenzoic acid, 3OC6HSL or 3OC14HSL.

[0010] In one aspect, the disclosure also provides a genetically engineered plant that can produce orthogonal carbon sources, such as opines or less common sugars, and bacteria with the corresponding catabolism pathways, which can respond to these signals.

[0011] In one aspect, the present disclosure provides a method for making a nitrogen-fixing bacterium, the method comprising a) identifying a host bacterium; b) selecting a donor bacterium having a nif cluster based on evolutionary distance between the host bacterium and the donor bacterium; and c) inserting the nif cluster of the donor bacterium to the host bacterium, thereby making a nitrogen-fixing bacterium. In some embodiments, the evolutionary distance between the host bacterium and the donor bacterium is less than 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, or 0.1% substitutions per site in 16S ribosomal RNA gene sequence. In some embodiments, the host bacterium and the donor bacterium are in the same genus, family, order, or class. In some embodiments, the donor bacterium is selected from Klebsiella, Pseudomonas, Azotobacter, Gluconacetobacter, Azospirillum, Azorhizobium, Rhodopseudomonas, Rhodobacter, Cyanothece, or Paenibacillus genus. In some embodiments, the host bacterium is selected from the group consisting of E. coli, Pseudomonas protegens Pf-5, and Rhizobium IRBG74. In some embodiments, the donor bacterium is selected from the group consisting of K. oxytoca, P. stutzeri, A. vinelandii, G. diazotrophicus, A. brasilense, A. caulinodans, R. palustris, R. sphaeroides, Cyanothece, and Paenibacillus. In some embodiments, the host bacterium is E. coli and the donor bacterium is K. oxytoca. In some embodiments, the host bacterium is Pseudomonas protegens Pf-5, and the donor bacterium is P. stutzeri. In some embodiments, the host bacterium is Rhizobium IRBG74, and the donor bacterium is R. sphaeroides. In some embodiments, the host bacterium is a nonsymbiotic bacterium, e.g., Azotobacter, Beijerinckia, or Clostridium bacterium. In some embodiments, the host bacterium is a symbiotic bacterium, e.g., Rhizobium, Frankia, or Azospirillum bacterium. In some embodiments, the host bacterium is symbiotic with a leguminous plant, an actinorhizal plant, or a cereal crop. In some embodiments, the inserted nif cluster is under inducible control.

[0012] In one aspect, the present disclosure provides a method of selecting a nif cluster of a donor bacterium that is compatible with a host bacterium, the method comprising a) performing a phylogenetic analysis for the donor bacterium and the host bacterium; b) determining evolutionary distance based on the phylogenetic analysis between the donor bacterium and the host bacterium is less than a reference value; and c) selecting the nif cluster of the donor bacterium for the host bacterium. In some embodiments, the phylogenetic analysis is performed by using distance-matrix, maximum parsimony, maximum likelihood, or Bayesian inference. In some embodiments, the phylogenetic analysis is performed by analyzing ribosomal RNA (e.g., 16s rRNA) substitution rate. In some embodiments, the reference value is 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, or 0.1% substitutions per site in 16S ribosomal RNA gene sequence. In some embodiments, the reference value is 500, 400, 300, 200, 100, 50, or 10 million years. In some embodiments, the method further comprises inserting the nif cluster to the host bacterium and evaluating the nitrogen fixation activity. In some embodiments, the nif cluster is under inducible control.

[0013] In one aspect, the present disclosure provides a bacterium comprising a nif cluster, where the nif cluster is under control of an exogenous control genetic element. In some embodiments, the nif cluster is an endogenous or exogenous nif cluster. In some embodiments, the exogenous control genetic element initiates promoter activities in response to an inducer (e.g., a chemical signal). In some embodiments, the promoter activities are measured by the below equation:

.delta. .times. J = .gamma. n .function. [ i = x tss + 1 x tss + 1 + n .times. m .function. ( i ) - i = x tss - 1 x 0 - 1 - n .times. m .function. ( i ) ] ##EQU00001##

where m(i) is number of transcripts at each position i from the FPKM normalized transcriptomic profiles, .gamma.=0.0067 s-1 is the degradation rate of mRNA and n is the window length before and after x.sub.tss. In some embodiments, the inducer is delivered to the bacterium by chemical delivery or biocontrol delivery. In some embodiments, the inducer is a chemical signal in seeds (e.g., cuminic acid), a native root exudate (e.g., arabinose, salicylic acid, vanillic acid, or narigenin), a chemical signal from a bacterium (e.g., 3OC6HSL, 3OC14HSL, DHBA, or DAPG), or a chemical signal from a genetically modified plant (e.g., Nopaline or Octopine).

[0014] The details of one or more embodiments of the invention are set forth in the description below. Other features or advantages of the present invention will be apparent from the following drawings and detailed description of several embodiments, and also from the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present disclosure, which can be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein. For purposes of clarity, not every component may be labeled in every drawing. It is to be understood that the data illustrated in the drawings in no way limit the scope of the disclosure. In the drawings:

[0016] FIGS. 1A-1F include diagrams showing transfer of nif clusters across species. (FIG. 1A) Eight nif clusters from free-living nitrogen fixing bacteria are aligned based on phylogenetic relationships of 16S rRNA sequences. The genes and operons are based on K. oxytoca M5al. Dots in the DNA line indicate where multiple regions were cloned from genomic DNA and combined to form one large plasmid-borne nif cluster. A complete list of strain genotypes is provided in Table 3. Nitrogenase activity from transfer of the native nif clusters was measured in three species. The activities of the R. palustris and R. sphaeroides nif clusters were also measured in 12 Rhizobia strains. Asterisks indicate ethylene production below the detection limit (<10 a.u.). Error bars represent s.d. from three independent experiments. (FIG. 1B) Transcriptomic profile of the native K. oxytoca nif cluster in K. oxytoca, compared with those obtained from its transfer to the indicated species. (FIG. 1C) Transcription levels (FPKM) of the native K. oxytoca nif cluster across species. Transcriptional units are underlined. (FIG. 1D) Transcription levels (FPKM) of the K. oxytoca nif genes in K. oxytoca (.fwdarw.Klebsiella) compared to that obtained when transferred to a new host. (FIG. 1E) Same as in (FIG. 1C), except the translational efficiency is compared, as calculated using ribosome profiling. (FIG. 1F) Same as in (FIG. 1D), except the ribosome densities (RD) are compared, as calculated using ribosome profiling. R2 in log-log plots was calculated from the line (y=x+b), where b is an expression variable between hosts.

[0017] FIGS. 2A-2M include diagrams showing the transfer of the refactored K. oxytoca nif clusters to R. sp. IRBG74. (FIG. 2A) The genetic systems for the controller for E. coli MG1655 (left) and R. sp. IRBG74 (right) are shown. A variant of T7 RNAP (R6232S, N-terminal lon tag, GTG start codon) is used for the E. coli controller. Several genetic parts were substituted to build the R. sp. IRBG74 controller (FIG. 16). The sequences for the genetic parts are provided in Table 5. (FIG. 2B) The response functions for the controllers with the reporter plasmid pMR-79 (Table 4 and Table 5). The IPTG concentrations used to induce nitrogenase were circled. (FIG. 2C) The genetic parts used to build the refactored v2.1 nif gene cluster are shown (Table 5). (FIG. 2D) The activity of the refactored nif gene cluster v2.1 in different hosts is shown. Asterisks indicate ethylene production below the detection limit (<10 a.u.). (FIG. 2E) The activities of the v2.1 promoters and terminators in E. coli MG1655 and R. sp. IRBG74 as calculated from RNA-seq data (see Materials and Methods). (FIG. 2F) The translation efficiency of the v2.1 nif genes in E. coli MG1655 and R. sp. IRBG74, as calculated using ribosome profiling and RNA-seq. Lines connect points that occur in the same operon. (FIG. 2G) The ribosome density (RD) is compared for the refactored v2.1 nif genes in a new host (E. coli MG155; R. sp. IRBG74) versus that measured for the nif genes from the native K. oxytoca cluster in K. oxytoca (.fwdarw.Klebsiella). The points corresponding to nifH is marked H. (FIGS. 2H-2L) The same as (FIGS. 2C-2G) but with the refactored nif cluster v3.2. Genetic parts are provided in Table 5. (FIG. 2M) Nitrogenase activity is shown as a function of T7 promoter strength. The refactored nif cluster v3.2 was expressed from three controller strains with varying strengths (FIG. 16). Error bars represent s.d. from three independent experiments.

[0018] FIGS. 3A-3F include diagrams showing the control of nitrogen fixation in A. caulinodans ORS571. (FIG. 3A) The controller is shown, carried on a pBBR1 origin plasmid (genetic parts are provided in Table 5). NifA and RpoN co-induce the expression of three sites in the genome (identified by consensus NifA binding sequences). (FIG. 3B) Expression from the nifH promoter was evaluated using a fluorescent reporter (see Materials and Methods). NifA and RpoN were complemented (+) individually or in combination in the A. caulinodans .DELTA.nifA strain where the genomic rpoN remains intact. (FIG. 3C) The response function for the induction of the nifH promoter by the controller is shown. (FIG. 3D) The nitrogenase activity is shown for wild-type A. caulinodans ORS571 compared to the .DELTA.nifA complemented with the controller plasmid (+) and the addition of 1 mM IPTG (+). (FIG. 3E) The effect of the absence or presence of 10 mM ammonium chloride is shown. The WT NifA from A. caulinodans ORS571 is compared to different combinations of amino acid substitutions with additional RpoN expression. NifA/RpoN expression is induced by 1 mM IPTG (+) for the .DELTA.nifA strain containing the controller plasmid pMR-121, 122, 123, and 124 (+). Asterisks indicate ethylene production below the detection limit (<10 au). (FIG. 3F) The nitrogenase activity is shown as a function of the oxygen concentration in the headspace (see Materials and Methods). The native nif cluster (wild-type A. caulinodans ORS571) is compared to the inducible version including the controller plasmid and 1 mM IPTG. Error bars represent s.d. from three independent experiments.

[0019] FIGS. 4A-4F include diagrams showing Nitrogenase activity of the inducible nif clusters in Pseudomonas protegens Pf-5. (FIG. 4A) The controllers, based on P. stutzeri NifA, were used for all three clusters. Plasmids and genetic parts are provided in Table 4 and Table 5. (FIG. 4B) The nif clusters from K. oxytoca, P. stutzeri, and A. vinelandii are shown. The deleted regions corresponding the NifLA regulators are marked. The dotted lines indicate that multiple regions from the genome were cloned and combined for form the nif cluster. The clusters were carried the plasmids pMR-4, 6, 8 (Table 4). (FIG. 4C) The induction of the nifH promoters from each species by the controller are shown (0.5 mM IPTG) (see Materials and Methods). (FIG. 4D) The nitrogenase activities of the native cluster (intact nifLA) is compared to the inducible clusters in the presence and absence of 0.5 mM IPTG. The dashed lines indicate the activity of the native clusters in the wild-type context (top to bottom, K. oxytoca M5al, P. stutzeri A1501 and A. vinelandii DJ). (FIG. 4E) The sensitivity of the native and inducible (+0.5 mM IPTG) nif clusters to 17.1 mM ammonium acetate are compared. Asterisks indicate ethylene production below the detection limit (<10 au). (FIG. 4F) The nitrogenase activity is shown as a function of the oxygen concentration in the headspace (see Materials and Methods). The native nif cluster is compared to the inducible version including the controller plasmid and 0.5 mM IPTG. Error bars represent s.d. from three independent experiments.

[0020] FIGS. 5A-5D include diagrams showing the control of nitrogenase activity with sensors that respond to diverse chemicals in the rhizosphere. (FIG. 5A) Schematic showing the origins of the chemicals. "Introduced DNA" refers to the genetic modification of the plant to produce nopaline and octopine. (FIG. 5B) The genetic sensors built for A. caulinodans are shown. Sequences for the genetic parts are provided in Table 5. (FIG. 5C) The response functions for the sensors are shown. Either the sensor expresses T7 RNAP, which then activates PT7, or it expresses NifA (P. protegens Pf-5) or NifA/RpoN (A. caulinodans) and activates the nifH promoter (species origin in parentheses). (FIG. 5D) The nitrogenase activity is measured in the presence or absence of inducer (see Materials and Methods). The refactored Klebsiella nif clusters v2.1 and v3.2 were used in E. coli MG1655 and R. sp. IRBG74, respectively. The inducible A. vinelandii nif cluster was used in P. protegens Pf-5. The controller containing nifA/rpoN was used in A. caulinodans .DELTA.nifA. The inducer concentrations are: 50 .mu.M vanillic acid, 500 .mu.M DHBA, 50 .mu.M cuminic acid, 25 nM 3OC6HSL, 500 nM 3OC14HSL, 33 .mu.M arabinose, 100 .mu.M naringenin, 100 nM DAPG, 200 .mu.M salicylic acid, 1 mM nopaline and 1 mM octopine. Error bars represent s.d. from three independent experiments.

[0021] FIG. 6 includes a plot of the growth curve of R. sp. IRBG74 in UMS minimal medium with varying carbon sources. Cultures grown overnight in 2 mL TY medium in 15 mL culture tubes at 30.degree. C. and 250 rpm were diluted to an OD.sub.600 of 0.02 into 1 mL of UMS minimal medium plus varying carbon sources in 96-deepwell plates and incubated for 16 hours at 30.degree. C. and 900 rpm. Bacterial growth was spectrophotometrically monitored at OD.sub.600 nm. Error bars represent s.d. from three independent experiments.

[0022] FIGS. 7A-7F include diagrams showing the nitrogenase activity when different inducible nif clusters are transferred to E. coli MG1655. (FIG. 7A) The same controller system based on K. oxytoca NifA was used for all three clusters. The controller plasmid pMR-99 and genetic parts are provided in Table 4 and Table 5. (FIG. 7B) The nif clusters from K. oxytoca, P. stutzeri, and A. vinelandii are shown. The deleted regions corresponding the NifLA regulators are marked. The dotted lines indicate that multiple regions from the genome were cloned and combined for form the nif cluster. The clusters were carried the plasmids pMR-3, 5, 7 (Table 4). (FIG. 7C) The induction of the nifH promoters from each species by the controller is shown (50 .mu.M IPTG) (see Materials and Methods) (FIG. 7D) The nitrogenase activities of the native cluster (intact nifLA) is compared to the inducible clusters in the presence and absence of 50 .mu.M IPTG. The dashed lines indicate the activity of the native clusters in the wild-type context (top to bottom, K. oxytoca M5al, P. stutzeri A1501 and A. vinelandii DJ). (FIG. 7E) Regulation of nitrogenase activity by ammonia. Ammonium tolerance of nitrogenase from the native (black bar) and inducible (gray bar) systems was tested in the presence of 17.1 mM ammonium acetate. Asterisks indicate ethylene production below the detection limit (<10 au). (FIG. 7F) Regulation of nitrogenase activity by oxygen. The native nif cluster is compared to the inducible version including the controller plasmid and 50 .mu.M IPTG. Nitrogenase activities were measured after 3 h of incubation at constant oxygen concentrations (0 to 3%) in the headspace (see Materials and Methods). Error bars represent s.d. from three independent experiments.

[0023] FIGS. 8A-8B include plots showing ammonium repression of the transferred nif clusters. Nitrogenase sensitivity to ammonium was measured by nitrogenase assay in the absence (-) or presence (+) of 17.1 mM ammonium acetate. The sensitivity of the native and inducible nif clusters in E. coli MG1655 (FIG. 8A) and P. protegens Pf-5 (FIG. 8B). Note that the data are from FIGS. 4A-4F and FIGS. 7A-7F. The nif clusters were induced by 50 .mu.M and 0.5 mM IPTG in E. coli MG1655 and P. protegens Pf-5, respectively. Asterisks indicate ethylene production below the detection limit (<10 au). Error bars represent s.d. from three independent experiments.

[0024] FIG. 9 includes a diagram showing the ribosome profiling data for the K. oxytoca native nif cluster in K. oxytoca M5al, E. coli MG1655, P. protegens Pf-5 and R. sp. IRBG74 (see Materials and Methods).

[0025] FIGS. 10A-10B include diagrams showing the effect of NifA overexpression on the nifH promoter activity in R. sp. IRBG74. (FIG. 10A) The reporter construct used to measure nifH promoter activity is shown. The nifH promoter activity was analyzed in the R. sp. IRBG74 wild-type background using flow cytometry. Additional copies of NifA of R. sp. IRBG74 increased activity of the R. sp. IRBG74 nifH promoter but failed to complement or enhance activity of the other nifH promoters including K. oxytoca, P. stutzeri and A. caulinodans. Error bars represent s.d. from three independent experiments. (FIG. 10B) Plasmid maps used to assess the effect of NifA overexpression in R. sp. IRBG74. WT, wild-type; Rsp, R. sp. IRBG74; Kox, K. oxytoca M5al; Pst, P. stutzeri A1501; Aca, A. caulinodans ORS571

[0026] FIGS. 11A-11C include diagrams showing Promoter characterization in R. sp. IRBG74 and P. protegens Pf-5. (FIG. 11A) Constitutive promoters are rank-ordered by their strength. Plasmids used to measure promoter activity are depicted on the top. (FIG. 11B) The strength of the T7 promoter wild-type and its variants was analyzed in the controller strains containing the IPTG-inducible T7 RNAP on the genome of R. sp. IRBG74 and P. protegens Pf-5 with 1 mM IPTG induction. A reporter plasmid used to measure T7 promoter activity is shown on the right. (FIG. 11C) Correlation of T7 promoter strength between species. Error bars represent s.d. from three independent experiments.

[0027] FIGS. 12A-12B include diagrams showing RBS characterization in R. sp. IRBG74 and P. protegens Pf-5. RBS library for GFP was designed using the RBS library calculator at the highest-resolution mode. (FIG. 12A) The strengths of the synthetic RBSs in R. sp. IRBG74 were analyzed in the plasmid pMR-40 containing the IPTG-inducible system with 1 mM IPTG induction. 33 of the RBSs spanning a range of 5,684-fold expression were selected and their sequences are provided in Table 6. (FIG. 12B) The strengths of the synthetic RBSs in P. protegens Pf-5 was analyzed in the plasmid pMR-65 containing the arabinose-inducible system with 7 .mu.M arabinose induction. 33 of the RBSs spanning a range of 1,075-fold expression were selected and their sequences are provided in Table 6.

[0028] FIGS. 13A-13B include diagrams showing the characterization of terminators for T7 RNAP in R. sp. IRBG74 (FIG. 13A) and P. protegens Pf-5 (FIG. 13B). (FIG. 13A) The strength of terminators was analyzed in the controller R. sp. IRBG74 strains MR16 containing the IPTG-inducible T7 RNAP on the genome with 1 mM IPTG induction. (FIG. 13B) Plasmids used to measure terminator strength are shown on right. Genetic parts are provided in Table 5. Error bars represent s.d. from three independent experiments.

[0029] FIG. 14 includes diagrams showing the response functions for the sensors in R. sp. IRBG74. Plasmids used to characterize the sensors are shown on top of each panel and provided in Table 4. Genetic parts are provided in Table 5. Error bars represent s.d. from three independent experiments. Experimental details are provided in Methods.

[0030] FIGS. 15A-15C include diagrams showing the response functions for the sensors in P. protegens Pf-5. The output changes as a function of input inducer concentrations. Plasmids used to characterize the sensors are shown on top of each panel. (FIG. 15A) Inducible promoter characterization in P. protegens Pf-5. (FIG. 15B) Optimization of the arabinose-inducible systems. Constitutive expression of a plasmid-borne AraE transporter decreased a dissociation constant of arabinose (dark gray). A mutation in the -10 region (TACTGT to TATATT) of the P.sub.BAD promoter increased promoter strength (black). (FIG. 15C) Optimization of IPTG-inducible systems. The IPTG-inducible promoters were induced by 1 mM IPTG. The combination of the P.sub.tac promoter and the LacI (Q18M/A47V/F161Y) protein yielded an expression range of 110-fold. Plasmids and genetic parts are provided in Table 4 and Table 5. Error bars represent s.d. from three independent experiments.

[0031] FIG. 16 includes diagrams showing the tuning controller strength in R. sp. IRBG74. The controller containing the IPTG-inducible T7 RNAP is integrated into the genome of R. sp. IRBG74 (top). Controller strengths were adjusted by modulating the RBS of T7 RNAP in the plasmids pMR-81, 82, and 83. Response functions of the T7 promoter were measured with the reporter plasmid pMR-79 (right) in the R. sp. IRBG74 controller strains MR16, MR17, and MR18. Genetic parts and RBS sequences are provided in Table 5 and Table 5. Error bars represent s.d. from three independent experiments.

[0032] FIG. 17 includes a plot showing the nitrogenase activity of the refactored nif clusters across species. Error bars represent s.d. from three independent experiments.

[0033] FIG. 18 includes diagrams showing RNA-seq (top) and Ribosome profiling (bottom) data, respectively in E. coli MG1655 and R. sp. IRBG74. The nif genes were induced by 1 mM IPTG for 6 hours (see Materials and Methods).

[0034] FIG. 19 includes diagrams showing RNA-seq (top) and ribosome profiling (bottom) data, respectively, in E. coli MG1655 and P. protegens Pf-5 and R. sp. IRBG74. The nif genes were induce by 1 mM, 0.1 mM, and 0.5 mM IPTG for 6 h in E. coli MG1655, P. protegens Pf-5 and R. sp. IRBG74, respectively (see Materials and Methods).

[0035] FIGS. 20A-20F include diagrams showing the transfer of the refactored nif cluster v3.2 in P. protegens Pf-5. (FIG. 20A) Controllers whose output is T7 RNAP from the genome of P. protegens Pf-5 are described. Substituted genetic parts including a new RBS and IPTG-inducible promoter for the controller optimization compared to the controller module pKT249 in E. coli MG1655 highlighted in red. The response functions for the controllers with the reporter plasmid pMR-80 was measured in the P. protegens Pf-5 controller strain MR7. Controllers driving the expression of GFP by the T7 promoter achieved large dynamic to 96-fold activation by IPTG. Error bars represent s.d. from three independent experiments. (FIG. 20B) The genetic parts used to build the refactored v3.2 nif gene cluster are shown (Table 5). (FIG. 20C) The activity of the refactored nif cluster v3.2. Nitrogenase expression was induced by 1 mM IPTG. (FIG. 20D) Function of the transcriptional parts of the cluster v3.2 was analyzed by RNA-seq (FIG. 19). The performance of the promoters (left) and terminators (right) was calculated (see Materials and Methods). (FIG. 20E) The translation efficiency of the nif genes v3.2 as calculated using ribosome profiling and RNA-seq. Lines connect points that occur in the same operon. (FIG. 20F) The ribosome density (RD) is compared for the refactored v3.2 nif genes in P. protegens Pf-5 versus that measured for the nif genes from the native K. oxytoca cluster in K. oxytoca (.fwdarw.Klebsiella).

[0036] FIG. 21 includes diagrams showing the response function of inducible promoters in A. caulinodans ORS571. Plasmids used to characterize inducible promoters are shown on top of each panel and provided in Table 4. Genetic parts are provided in Table 5. Error bars represent s.d. from three independent experiments.

[0037] FIG. 22 includes a diagram showing the multiple sequence alignment of NifA of A. caulinodans ORS571 with R. spheroides 2.4.1 was generated using MUSCLE2. The corresponding residues for ammonium tolerance in R. sphaeroides are outlined. The A. caulinodans strand corresponds to SEQ ID NO: 293, and the R. sphaeroides strand corresponds to SEQ ID NO: 292.

[0038] FIGS. 23A-23B include diagrams showing functional testing of the NifA homologues that activate the nifH promoters. (FIG. 23A) The ability of the various NifA to activate the nifH promoters was tested with pairwise combinations of the nifH promoters and the NifA in E. coli MG1655 and P. protegens Pf-5. Error bars represent s.d. from three independent experiments. (FIG. 23B) Plasmids used to measure nifH promoter activity by NifA overexpression are shown and provided in Table 4. Genetic parts are provided in Table 5. Pst, P. stutzeri A1501; Avi, A. vinelandii DJ; Kox, K. oxytoca M5al

[0039] FIGS. 24A-24B include diagrams showing optimization of the controllers in P. protegens Pf-5 and E. coli MG1655 that induce the nifH promoters. (FIG. 24A) The controllers with different strengths were designed by RBS replacement and tested with the reporter plasmids (pMR103-105) in which each of the three nifH promoter is fused to sfgfp (Methods). The nifH promoters were induced with 0.5 mM IPTG. Genetic parts and RBS sequences are provided in Table 5 and 6, respectively. (FIG. 24B) Activation of the nifH promoters in the E. coli MG1655 containing the controller plasmid pMR102 was tested with the reporter plasmids pMR106-108. The P. protegens Pf-5 controller strain MR10 was used to drive expression of the nifH promoter of K. oxytoca and the controller strain MR9 was used to drive expression of the nifH promoters of P. stutzeri and A. vinelandii. The nifH promoters were induced with 0.05 mM IPTG and 0.5 mM IPTG in E. coli MG1655 and P. protegens Pf-5, respectively. Error bars represent s.d. from three independent experiments.

[0040] FIG. 25 includes diagrams showing the effect of oxygen on the activity of the nifH promoters. Expression from the nifH promoters was analyzed in E. coli MG1655 containing the controller plasmid pMR102, P. protegens Pf-5 MR10 (for K. oxytoca) and MR9 (for P. stutzeri and A. vinelandii) at varying initial oxygen levels in the headspace. The three nifH promoters were induced with 0.05 mM IPTG and 0.5 mM IPTG in E. coli MG1655 and P. protegens Pf-5, respectively, and incubated at varying initial oxygen concentrations. Oxygen has no effects on nifH expression in both strains. Error bars represent s.d. from three independent experiments.

[0041] FIGS. 26A-26B include diagrams describing the nitrogenase activity assay. (FIG. 26A) Nitrogenase activity assay at constant oxygen levels in the headspace. Experimental setup used in this study to analyze oxygen tolerance of nitrogenase. Following the expression induction of nitrogenase with preincubation under low oxygen conditions, targeted oxygen concentrations in the headspace is maintained by oxygen spiking while monitoring with oxygen monitoring system (Methods). (FIG. 26B) Nitrogenase activity in E. Coli MG1655 and P. protegens Pf-5 over a course of three hours.

[0042] FIG. 27 includes diagrams showing the effect of the rnf and fix complex on nitrogenase activity. The modified nif clusters of A. vinelandii on the plasmids pMR25-28 were analyzed in the controller strain P. protegens Pf-5 MR9. The deleted regions from the clusters were provided in Table 4. Nitrogenase was induced with 0.5 mM IPTG. Removing the rnf complex from the cluster abrogated activity. The cluster without the fixABCX complex showed identical oxygen tolerance to the cluster with the complex. Error bars represent s.d. from three independent experiments.

[0043] FIGS. 28A-28C include diagrams showing regulation of nitrogenase activity in E. coli MG1655 "Marionette" strain5. (FIG. 28A) Controller plasmids used to drive expression of T7 promoters. (FIG. 28B) Inducibility of the T7 promoter by the controller plasmids encoding T7 RNAP under the regulation of the 12 sensors was tested with a reporter plasmid pMR121 (right). (FIG. 28C) Inducible control of nitrogenase activity in response to 12 inducers was with the plasmid pMR136 (right) carrying the refactored nif cluster v2.1 on pBBR1 origin. The choline-Cl inducible system was omitted for activity assay as the system was not inducible. For the DAPG-, DHBA-, and vanillic acid-inducible system, the refactored cluster was carried on a lower copy number plasmid pMR31 (right) as transformation of the plasmid pMR29 gave rise to no colony formation. The inducers concentrations are: 400 .mu.M arabinose, 1 mM choline-Cl, 500 nM 3OC14HSL, 50 .mu.M cuminic acid, 25 nM 3OC6HSL, 25 .mu.M DAPG, 500 .mu.M DHBA, 1 mM IPTG, 100 nM aTc, 250 .mu.M naringenin, 50 .mu.M vanillic acid, and 250 .mu.M salicylic acid. Plasmid and genetic parts are provided in Table 4 and 5. Error bars represent s.d. from three independent experiments.

[0044] FIG. 29 includes schematic plasmid maps used to assess the effect of inducible expression of NifA/RpoN on the activity of the nifH promoter in A. caulinodans ORS571.

[0045] FIG. 30A-30B include diagrams showing the phylogenetic relationships of 10 diazotrophs based on 16S ribosomal RNA sequences. The scale bar indicates 2% substitutions per site. The clusters based on evolutionary closeness are circled. FIG. 30B shows the relative nitrogenase activity in three host strains (E. coli, Pseudomonas protegens Pf-5, and Rhizobium sp. IRBG74) carrying each of the 10 nif clusters. The result suggests that the phylogenetic closeness has a predictive power for achieving highest nitrogenase activity in a new host that lacks an endogenous nif cluster.

DETAILED DESCRIPTION OF THE INVENTION

[0046] Nitrogen fixation in the root nodules of leguminous plants is a major contributor to world food production and therefore, the practical applications of this field are of major interest. Legumes obtain nitrogen from air through bacteria residing in root nodules, some species of which also associate with cereals but do not fix nitrogen under these conditions. Disabling native regulation can turn on expression, even in the presence of nitrogenous fertilizer and low O.sub.2, but continuous nitrogenase production confers an energetic burden.

[0047] The present disclosure in some aspects describes the surprising discovery that bacteria can be genetically altered in a manner that will enable the bacteria to deliver fixed nitrogen to cereal crops. Several strategies to implement control over nitrogen fixation in bacteria that live on or inside the roots of cereals are described. At least two approaches can be taken. In one embodiment, the native regulation is replaced. In alternative embodiments, a nif cluster is transferred from another species and placed under inducible control. The Examples section below includes a description of the achievement of these two approaches in multiple species with multiple constructs. For example, A. caulinodans, ammonium-independent control can be achieved using a sensor to drive the co-expression of a NifA mutant and RpoN in a .DELTA.nifA strain. Rhizobium sp. IRBG74 can be engineered to express functional nitrogenase under free living conditions either by transferring a native nif cluster from Rhodobacter or a refactored cluster from Klebsiella. Multiple approaches enable P. protegens Pf-5 to express functional nitrogenase, of which the transfer of the nif cluster from Azotobacter vinelandii DJ yields the highest activity and O.sub.2 tolerance.

[0048] To date, it has not been shown that a Rhizobium strain can be engineered to fix nitrogen under free-living conditions when it does not do so naturally. Some Rhizobia isolated from legume root nodules are also cereal endophytes, however most are unable to fix nitrogen under free-living conditions (outside of the nodule) (Ramachandran, V. K., East, A. K., Karunakaran, R., Downie, J. A. & Poole, P. S. Adaptation of Rhizobium leguminosarum to pea, alfalfa and sugar beet rhizospheres investigated by comparative transcriptomics. Genome biology 12, R106 (2011); Frans, J. et al. in Nitrogen Fixation 33-44 (Springer, 1990)). There have been reports of cereal yield improvements due to these bacteria, including a 20% increase for rice by Rhizobium sp. IRBG74, but this is likely due to other growth-promoting mechanisms, such as improved nutrient uptake or root formation (Ramachandran, V. K., East, A. K., Karunakaran, R., Downie, J. A. & Poole, P. S. Adaptation of Rhizobium leguminosarum to pea, alfalfa and sugar beet rhizospheres investigated by comparative transcriptomics. Genome biology 12, R106 (2011); Delmotte, N. et al. An integrated proteomics and transcriptomics reference data set provides new insights into the Bradyrhizobium japonicum bacteroid metabolism in soybean root nodules. Proteomics 10, 1391-1400 (2010); Hoover, T. R., Imperial, J., Ludden, P. W. & Shah, V. K. Homocitrate is a component of the iron-molybdenum cofactor of nitrogenase. Biochemistry 28, 2768-2771 (1989)). Azorhizobium caulinodans ORS571 is exceptional because it is able to fix nitrogen in both aerobic free-living and symbiotic states, has been shown to be a rice and wheat endophyte, and does not rely on plant metabolites to produce functional nitrogenase. However, when Rhizobia or Azorhizobium species are living in cereal roots, there is low nitrogenase expression and .sup.15N.sub.2 transfer rates suggest any reported uptake is due to bacterial death.

Cereal Crops, Nitrogen Fixation, and Bacteria

[0049] Cereal crops are broadly defined as any grass cultivated for the edible components of its grain (also referred to as caryopsis), composed of the endosperm, germ, and bran. Cereal crops are considered staple crops in many parts of the world. They are grown in greater quantities and provide more food energy worldwide than any other type of crop. Non-limiting examples of cereal crops include maize, rye, barley, wheat, sorghum, oats, millet and rice. As used herein, the terms "cereal crop" and "cereal plant" are used interchangeably.

[0050] Nitrogen fixation is the process by which atmospheric nitrogen is assimilated into organic compounds as part of the nitrogen cycle. The fixation of atmospheric nitrogen associated with specific legumes is the result of a highly specific symbiotic relationship with rhizobial bacteria. These indigenous bacteria dwell in the soil and are responsible for the formation of nodules in the roots of leguminous plants as sites for the nitrogen fixation. Most Rhizobium symbioses are confined to leguminous plants. Furthermore, Rhizobium strains which fix nitrogen in association with the agriculturally-important temperate legumes are usually restricted in their host range to a single legume genus.

[0051] The nif genes are genes encoding enzymes involved in the fixation of atmospheric nitrogen into a form of nitrogen available to living organisms. The primary enzyme encoded by the nif genes is the nitrogenase complex which converts atmospheric nitrogen (N.sub.2) to other nitrogen forms (e.g. ammonia) which the organism can process. As used herein, the term "nif cluster" refers to a gene cluster comprising nif genes. As used herein, the term "refactored" refers to an engineered gene cluster, i.e. its genes have reordered, deleted or altered in some way.

[0052] Rhizobia are diazotrophic bacteria. In general, they are gram negative, motile, non-sporulating rods. In terms of taxonomy, they fall into two classes: alphaproteobacteria and betaproteobacteria. Non-limiting examples of rhizobia include Azorhizobium caulinodans, Rhizobium(R.) sp. IRBG74, R. radiobacter, R. rhizogenes, R. rubi, R. vitis, Alfalfa Rhizobia (R. meliloti), Chickpea Rhizobia (Rhizobium sp.), Soybean Rhizobia (Bradyrhizobium japonicum), Leucaena Rhizobia (Rhizobium sp.), R. leguminosarum by trifolii, R. leguminosarum by phaseoli, and Rhizobium leguminosarum by viciae (see for example U.S. Pat. No. 7,888,552, herein incorporated by reference). In some embodiments, the rhizobia of the present invention are Azorhizobium caulinodans. In some embodiments, the rhizobia of the present invention are not Azorhizobium caulinodans.

[0053] As used herein, the term "free-living conditions" refers to a bacterium (e.g. rhizobium) that is not within a leguminous root nodule. It generally refers to something that has not formed a parasitic (or dependent) relationship with another organism or is not on a substrate. As used herein, the term "symbiotic" refers to the interaction between two organisms living in close proximity. Close proximity can be about 0.2 .mu.m, 0.4 .mu.m, 0.6 .mu.m, 0.8 .mu.m, 1 .mu.m, 5 .mu.m, 10 .mu.m, 20 .mu.m, 50 .mu.m, 100 .mu.m, 500 .mu.m, 1 mm, 1 cm, 5 cm, 10 cm. Close proximity can also be less than 0.2 .mu.m. In many cases, a symbiotic relationship refers to a mutually beneficial interaction.

[0054] As used herein, "aerobic free-living conditions" refer to conditions under which a bacterium is not within a leguminous root nodule and the bacterium is in the presence of oxygen. Aerobic free-living conditions can also be referred to as nonsymbiotic or non-parasitic conditions in the presence of oxygen. The bacterium can be in close proximity to a crop, as defined above.

[0055] As used herein, the term "endophyte" refers to a group of organisms, often fungi and bacteria, that live within living plant cells for at least part of its life cycle without having an apparent detrimental effect on the plant cell. This is contrasting with an epiphyte, which is a plant that grows on another plant, without being parasitic.

[0056] As used herein, the term "diazotroph" refers to microorganisms that are able to grow without external sources of fixed nitrogen. The group includes some bacteria and some archae. There are free-living and symbiotic diazotrophs. An example of a free-living diazotroph is Klebsiella pneumoniae. K. pneumoniae is a facultative anaerobes--these species can grow either with or without oxygen, but they only fix nitrogen anaerobically.

[0057] As used herein, the term "Alphaproteobacteria" refers to a diverse class of bacteria falling under the phylum Proteobacteria. Non-limiting examples of Alphaproteobacteria include species Rhodobacter sphaeroides and Rhodopseudomonas palustris. As used herein, the term "Gammaproteobacteria" refers to another class of bacteria falling under the phylum of Proteobacteria. All proteobacteria are gram negative. As used herein, the term "Cyanobacteria" refers to a phylum of bacteria that obtain their energy through photosynthesis. They are also referred to as Cyanophyta. They have characteristic internal membranes and thylakoids, the latter being for photosynthetic purposes. As used herein, the term "Firmicutes" refer to a phylum of bacteria. This phylum includes the classes Bacilli, Clostridia, and Thermolithobacteria.

Nif Genes

[0058] Typically, the genes necessary for nitrogen fixation occur together in a gene cluster, including the nitrogenase subunits, the biosynthesis of metalloclusters cluster and, electron transport, and regulator proteins. Nif genes are genes that encode the enzyme involved in nitrogen fixation. In most cases nif genes occur as an operon. Some of these genes encode the subunits for the nitrogenase complex, which is the primary enzyme imparting the ability to convert atmospheric nitrogen (N.sub.2) to forms of nitrogen accessible to living organisms. In most genes, the regulation of the nif gene transcription is conducted by NifA protein, which is responsive to nitrogen levels. When there are nitrogen deficits, NtrC activates NifA expression, which in turn leads to the activation of the remaining nif genes. When nitrogen levels are adequate or in excess, NifL protein, encoded by NifL, inhibits NifA activity.

[0059] Nif gene pathways are generally sensitive to small changes in expression. Important genes include nifHDK, which form the subunits for nitrogenase. The chaperone NifY is required to achieve full activity and broadens the tolerance to changes in expression level. NifJ and nif regulate electron transport. The nifUSVWZM operon encodes proteins for early Fe--S cluster formation (NifUS) and proteins for component maturation (NifVWZ for Component I and NifM for Component II), whereas nifBQ encodes proteins for FeMo-co core synthesis (NifB) and molybdenum integration (NifQ). NifEN is tolerant to varied expression levels.

[0060] Exemplary sequences for various nif genes are provided in Table 5. Non-limiting examples of nif genes include nifH, nifD, nifK, nifE, nifN, nifU, nifS, nifV, nifW, nifX, nifB, nifQ, nifY, nifT, nifJ, nifF, nifX, nifU, and nifS.

Nitrogen Fixation and Regulatory Elements

[0061] The nitrogen fixation (nif) genes are organized as genomic clusters, ranging from a 10.5 kb single operon in Paenibacillus to 64 kb divided amongst three genomic locations in A. caulinodans. Conserved genes include those encoding the nitrogenase enzyme (nifHDK), FeMoCo biosynthesis, and chaperones. Species that can fix nitrogen under more conditions tend to have larger gene clusters that include environment-specific paralogues, alternative electron transport routes, and oxygen protective mechanisms. Often, the functions of many genes in the larger clusters are unknown.

[0062] There is evolutionary evidence for the lateral transfer of nif clusters between species (Pascuan, C., Fox, A. R., Soto, G. & Ayub, N. D. Exploring the ancestral mechanisms of regulation of horizontally acquired nitrogenases. Journal of molecular evolution 81, 84-89 (2015); Kechris, K. J., Lin, J. C., Bickel, P. J. & Glazer, A. N. Quantitative exploration of the occurrence of lateral gene transfer by using nitrogen fixation genes as a case study. Proceedings of the National Academy of Sciences 103, 9584-9589 (2006)). However, achieving such a transfer via genetic engineering poses a challenge as many things can go awry, including differences in regulation, missing genes, and the intracellular environment (Frans, J. et al. in Nitrogen Fixation 33-44 (Springer, 1990); Poudel, S. et al. Electron transfer to nitrogenase in different genomic and metabolic backgrounds. Journal of bacteriology 200, e00757-00717 (2018); Thony, B., Anthamatten, D. & Hennecke, H. Dual control of the Bradyrhizobium japonicum symbiotic nitrogen fixation regulatory operon fixR nifA: analysis of cis- and trans-acting elements. Journal of bacteriology 171, 4162-4169 (1989); Han, Y. et al. Interspecies Transfer and Regulation of Pseudomonas stutzeri A1501 Nitrogen Fixation Island in Escherichia coli. Journal of microbiology and biotechnology 25, 1339-1348 (2015)). Nitrogenase is under stringent control because it is oxygen sensitive and energetically expensive: it can make up 20% of the cell mass and each NH.sub.3 requires .about.40 ATP. It is also irreversibly deactivated by oxygen. Across species, transcription of nif genes is strongly repressed by fixed nitrogen (ammonia) and oxygen with these signals converging on the NifA regulatory protein that works in concert with the sigma factor RpoN. Diverse, species-specific, and often poorly understood signals control these regulators, including plant-produced chemicals, ATP, reducing power, temperature, and carbon sources. Those bacteria that can fix nitrogen in a wider range of environmental conditions tend to be controlled by more complex regulatory networks.

[0063] When a nif cluster is transferred from one species to another, it either preserves its regulation by environmental stimuli or has an unregulated constitutive phenotype. Maintaining the native regulation, notably ammonium repression, limits their use in agriculture because such levels are likely to fluctuate according to soil types, irrigation, and fertilization. Nitrogen-fixing diazotrophs have been engineered to reduce ammonia sensitivity by disrupting NifL or mutating NifA and placing the entire cluster under the control of T7 RNA polymerase (RNAP). Constitutive expression of nitrogenase is also undesirable as it imparts a fitness burden on the cells. For example, when the nif cluster from P. stutzeri A1501 was transferred to P. protegens Pf-5, this was reported to result in sufficient ammonia production to support maize and wheat growth, but the bacteria quickly declined after a month when competing with other species in soil. Constitutive activity is detrimental even before the bacteria are introduced to the soil, impacting production, formulation, and long-term storage. Therefore, uncontrolled nitrogenase production could lead to more expensive production, shorter shelf life, and more in-field variability.

[0064] An important aspect of the nif clusters or nif genes the present disclosure is that they can each be under the control of a regulatory element. In some embodiments, 2 or more genes are under the control of a regulatory element. In some embodiments, all the genes are under the control of a regulatory element. The regulatory elements may also be activation elements or inhibitory elements. An activation element is a nucleic acid sequence that when presented in context with a nucleic acid to be expressed will cause expression of the nucleic acid in the presence of an activation signal. An inhibitory signal is a nucleic acid sequence that when presented in context with a nucleic acid to be expressed will cause expression of the nucleic acid unless an inhibitory signal is present. Each of the activation and inhibitory elements may be a promoter, such as a bacteriophage T7 promoter, sigma 70 promoter, sigma 54 promoter, lac promoter, etc. As used herein, the term "promoter" is intended to refer to those regulatory sequences which are sufficient to enable the transcription of an operably linked DNA molecule. Promoters may be constitutive or inducible. As used herein, the term "constitutive promoter" refers to a promoter that is always on (i.e. causing transcription at a constant level). Examples of constitutive promoters include, without limitation, sigma 70 promoter, bla promoter, lacI. promoter, etc. Non-limiting examples of inducible promoters are shown in Table 1. The P.sub.A1lacO1 promoter is another example of an inducible promoter that can be used in the present invention.

TABLE-US-00001 TABLE 1 Examples of regulatory elements (e.g. inducible promoters, repressors). Essential regulatory Name Chemical inducer and/or repressor gene(s) ParaBAD L-arabinose (ON) & glucose (OFF) araC ("PBAD") PrhaBAD L-rhamnose (ON) & glucose (OFF) rhaR &rhaS Plac lactose or IPTG (ON) & glucose lacI (OFF) Ptac lactose or IPTG (ON) lacI Plux acyl-homoserine lactone (ON) luxR Ptet tetracycline or aTc (ON) tetR Psal salycilate (ON) nahR Ptrp tryptophan (OFF) (NONE) Ppho phosphate (OFF) phoB & phoR

[0065] Inducible promoters allow regulation of gene expression and can be regulated by exogenously supplied compounds, environmental factors such as temperature, or the presence of a specific physiological state, e.g., acute phase, a particular differentiation state of the cell, or in replicating cells only. Inducible promoters and inducible systems are available from a variety of commercial sources, including, without limitation, Invitrogen, Clontech and Ariad. Many other systems have been described and can be readily selected by one of skill in the art. Examples of inducible promoters regulated by exogenously supplied promoters include the zinc-inducible sheep metallothionine (MT) promoter, the dexamethasone (Dex)-inducible mouse mammary tumor virus (MMTV) promoter, the T7 polymerase promoter system [WO 98/10088]; the ecdysone insect promoter [No et al, Proc. Natl. Acad. Sci. USA, 93:3346-3351 (1996)], the tetracycline-repressible system [Gossen et al, Proc. Natl. Acad. Sci. USA, 89:5547-5551 (1992)], the tetracycline-inducible system [Gossen et al, Science, 268:1766-1769 (1995), see also Harvey et al, Curr. Opin. Chem. Biol., 2:512-518 (1998)], the RU486-inducible system [Wang et al, Nat. Biotech., 15:239-243 (1997) and Wang et al, Gene Ther., 4:432-441 (1997)] and the rapamycin-inducible system [Magari et al, J. Clin. Invest., 100:2865-2872 (1997)]. Still other types of inducible promoters which may be useful in this context are those which are regulated by a specific physiological state, e.g., temperature, acute phase, a particular differentiation state of the cell, or in replicating cells only.

[0066] As used herein, the term "terminator" (as referred to as a transcription terminator) is a section of nucleic acid sequence that marks the end of a gene or operon in genomic DNA during transcription. They stop transcription of a polymerase. Terminators can be classified into several groups. At the first group of termination signals the core enzyme can terminate in vitro at certain sites in the absence of any other factors (as tested in vitro). These sites of termination are called intrinsic terminators or also class I terminators. Intrinsic terminators usually share one common structural feature, the so called hairpin or stem-loop structure. On the one hand the hairpin comprises a stem structure, encoded by a dG-dC rich sequence of dyad symmetrical structure. On the other hand the terminator also exhibits a dA-dT rich region at the 3'-end directly following the stem structure. The uridine rich region at the 3' end is thought to facilitate transcript release when RNA polymerase pauses at hairpin structures. Two or more terminators can be operatively linked if they are positioned to each other to provide concerted termination of a preceding coding sequence. Particularly preferred, the terminator sequences are downstream of coding sequences, i.e. on the 3' position of the coding sequence. The terminator can e.g. be at least 1, at least 10, at least 30, at least 50, at least 100, at least 150, at least 200, at least 250, at least 300, at least 400, at least 500 nucleotides downstream of the coding sequence or directly adjacent. Examples of terminators include, but are not limited to, T7 terminator, rrnBT1, L3S2P21, tonB, rrnA, rrnB, rrnD, RNAI, crp, his, ilv lambda, M13, rpoC, and trp (see for example U.S. Pat. No. 9,745,588, incorporated herein by reference).

[0067] RpoN

[0068] As used herein "RpoN" refers to a gene that encodes the sigma factor sigma-54 (.sigma.54, sigma N, or RpoN), a protein in Escherichia coli and other species of bacteria. Sigma factors are initiation factors that promote attachment of RNA polymerase to specific initiation sites and are then released. Bacteria normally only have one functional copy of the alternative sigma factor, .sigma.54 or RpoN, which regulates a complex genetic network that extends into various facets of bacterial physiology, including metabolism, survival in strenuous environments, production of virulence factors, and formation of biofilms. RpoN is one of seven RNA polymerase sigma subunits in E. coli required for promoter-initiated transcription and RpoN plays a major role in the response of E. coli to nitrogen-limiting conditions. Under such conditions, RpoN directs the transcription of at least 14 E. coli operons/regulators in the nitrogen regulatory (Ntr) response. RpoN also plays an important role in stress resistance (e.g. resistance to osmotic stress) and virulence of bacteria. RpoN is structurally and functionally distinct from the other E. coli .sigma. factors. It is able to bind promoter DNA in the absence of core RNA polymerase and it recognizes promoter sequences with conserved GG and GC elements located -24 to -12 nucleotides upstream of the transcription start site. Additionally, Regulatory proteins like NtrB and NtrC can activate .sigma.54 holoenzyme.

[0069] Without being bound by theory or mechanism, it is believed that RpoN works in concert with NifA to turn on the transcription of nif clusters. An exemplary sequence for RpoN is provided in Table 5.

Gene Cluster Nucleic Acids

[0070] As used herein, a "gene cluster" or "genetic cluster" refers to a set of two or more genes that encode gene products. A target, naturally occurring, or wild type genetic cluster can be used as the original model for refactoring. In some embodiments, the gene products are enzymes. In some embodiments, the gene products of a genetic cluster function in a biosynthetic pathway. In some embodiments, the gene cluster encodes proteins of the nif nitrogen fixation pathway.

[0071] The genetic clusters can encode proteins of a biosynthetic pathway. A biosynthetic pathway, as used herein, refers to any pathway found in a biological system that involves more than one protein. In some instances, these pathways involve 2-1,000 proteins. In other instances the number of proteins involved in a biosynthetic pathway may be 2-500, 2-100, 5-1000, 5-500, 5-100, 5-10, 10-1,000, 10-900, 10-800, 10-700, 10-600, 10-500, 10-400, 10-300, 10-200, 10-100, 50-1,000, 50-500, 50-100, 100-1,000, or 100-500. Examples of biosynthetic pathways include but are not limited to the nitrogen fixation pathway.

[0072] In some instances, the refactored genetic clusters have naturally occurring non-coding DNA, naturally occurring regulatory sequences, and/or non-essential genes that have been removed from at least one or in some instances all of the transcriptional units. These can be replaced by synthetic regulatory sequences, not replaced at all or replaced by spacers. A spacer simply refers to a set of nucleotides or analogs thereof that don't have a function such as coding for a protein or in any way regulating the activity of the gene cluster.

[0073] The genetic components in the genetic cluster typically will include at least one regulatory element. A synthetic regulatory element is any nucleic acid sequence which plays a role in regulating gene expression and which differs from the naturally occurring regulatory element. It may differ for instance by a single nucleotide from the naturally occurring element. In some cases, it is an exogenous regulatory element (i.e. not identical to the naturally occurring version). Thus, a "regulatory element" refers to a nucleic acid having nucleotide sequences that influence transcription or translation initiation or rate, or stability and/or mobility of a transcription or translation product. Regulatory regions include, without limitation, promoter sequences, ribosome binding sites, ribozymes, enhancer sequences, response elements, protein recognition sites, inducible elements, protein binding sequences, 5' and 3' untranslated regions (UTRs), transcriptional start sites, transcription terminator sequences, polyadenylation sequences, introns, and combinations thereof.

[0074] The genetic clusters can be expressed in vivo in an organism or in vitro in a cell. The organism or cell can be any organism or cell in which a DNA can be introduced. For example, organisms and cells can include prokaryotes and eukaryotes (i.e. yeast, plants). Prokaryotes include but are not limited to Cyanobacteria, Bacillus subtilis, E. coli, Clostridium, and Rhodococcus. Eukaryotes include, for instance, algae (Nannochloropsis), yeast such as, S. cerevisiae and P. pastoris, plant cells, mammalian cells. Thus, some aspects of this disclosure relate to engineering of a cell to express proteins from the modified genetic clusters.

[0075] In some embodiments of the present disclosure provides a genetic cluster includes a nucleotide sequence that is at least about 85% or more homologous or identical to the entire length of a naturally occurring genetic cluster sequence, e.g., at least 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 50% or more of the full length naturally occurring genetic cluster sequence). In some embodiments, the nucleotide sequence is at least about 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% homologous or identical to a naturally occurring genetic cluster sequence. In some embodiments, the nucleotide sequence is at least about 85%, e.g., is at least about 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% homologous or identical to a genetic cluster sequence, in a fragment thereof or a region that is much more conserved, such as an essential, but has lower sequence identity outside that region. The disclosure also provides a nucleotide sequence that is at least about 85%, e.g., is at least about 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to any nucleotide sequence as described herein or an amino acid sequence that is at least about 85%, e.g., is at least about 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to any amino acid sequence as described herein.

[0076] Calculations of homology or sequence identity between sequences (the terms are used interchangeably herein) are performed as follows. To determine the percent identity of two nucleic acid sequences, the sequences are aligned for optimal comparison purposes (e.g., gaps can be introduced in one or both of a first and a second amino acid or nucleic acid sequence for optimal alignment and non-homologous sequences can be disregarded for comparison purposes). The length of a reference sequence aligned for comparison purposes is at least 80% of the length of the reference sequence, and in some embodiments is at least 90% or 100%. The nucleotides at corresponding amino acid positions or nucleotide positions are then compared. When a position in the first sequence is occupied by the same nucleotide as the corresponding position in the second sequence, then the molecules are identical at that position (as used herein nucleic acid "identity" is equivalent to nucleic acid "homology"). The percent identity between the two sequences is a function of the number of identical positions shared by the sequences, taking into account the number of gaps, and the length of each gap, which need to be introduced for optimal alignment of the two sequences.

[0077] In some embodiments the gene clusters are native gene clusters. In some embodiments, the gene clusters are refactored gene clusters. In some instances, the nucleic acids may include non-naturally occurring nucleotides and/or substitutions, i.e. Sugar or base substitutions or modifications.

[0078] One or more substituted sugar moieties include, e.g., one of the following at the 2' position: OH, SH, SCH3, F, OCN, OCH3OCH3, OCH3O(CH2)n CH3, O(CH2)n NH2 or O(CH2)n CH3 where n is from 1 to about 10; Ci to C10 lower alkyl, alkoxyalkoxy, substituted lower alkyl, alkaryl or aralkyl; Cl; Br; CN; CF3; OCF3; O-, S-, or N-alkyl; O-, S-, or N-alkenyl; SOCH3; SO2 CH3; ONO2; NO2; N3; NH2; heterocycloalkyl; heterocycloalkaryl; aminoalkylamino; polyalkylamino; substituted silyl; an RNA cleaving group; a reporter group; an intercalator; a group for improving the pharmacokinetic properties of a nucleic acid; or a group for improving the pharmacodynamic properties of a nucleic acid and other substituents having similar properties. Similar modifications may also be made at other positions on the nucleic acid, particularly the 3' position of the sugar on the 3' terminal nucleotide and the 5' position of 5' terminal nucleotide. Nucleic acids may also have sugar mimetics such as cyclobutyls in place of the pentofuranosyl group.

[0079] Nucleic acids can also include, additionally or alternatively, nucleobase (often referred to in the art simply as "base") modifications or substitutions. As used herein, "unmodified" or "natural" nucleobases include adenine (A), guanine (G), thymine (T), cytosine (C) and uracil (U). Modified nucleobases include nucleobases found only infrequently or transiently in natural nucleic acids, e.g., hypoxanthine, 6-methyladenine, 5-Me pyrimidines, particularly 5-methylcytosine (also referred to as 5-methyl-2' deoxycytosine and often referred to in the art as 5-Me-C), 5-hydroxymethylcytosine (HMC), glycosyl HMC and gentobiosyl HMC, isocytosine, pseudoisocytosine, as well as synthetic nucleobases, e.g., 2-aminoadenine, 2-(methylamino)adenine, 2-(imidazolylalkyl)adenine, 2-(aminoalklyamino)adenine or other heterosubstituted alkyladenines, 2-thiouracil, 2-thiothymine, 5-bromouracil, 5-hydroxymethyluracil, 5-propynyluracil, 8-azaguanine, 7-deazaguanine, N6 (6-aminohexyl)adenine, 6-aminopurine, 2-aminopurine, 2-chloro-6-aminopurine and 2,6-diaminopurine or other diaminopurines. See, e.g., Kornberg, "DNA Replication," W. H. Freeman & Co., San Francisco, 1980, pp 75-' 7' 7; and Gebeyehu, G., et al. Nucl. Acids Res., 15:4513 (1987)). A "universal" base known in the art, e.g., inosine, can also be included.

[0080] Methods to deliver expression vectors or expression constructs into cells, for example, into bacteria, yeast, or plant cells, are well known to those of skill in the art. Nucleic acids, including expression vectors, can be delivered to prokaryotic and eukaryotic cells by various methods well known to those of skill in the relevant biological arts. Methods for the delivery of nucleic acids to a cell, include, but are not limited to, different chemical, electrochemical and biological approaches, for example, heat shock transformation, electroporation, transfection, for example liposome-mediated transfection, DEAE-Dextran-mediated transfection or calcium phosphate transfection. In some embodiments, a nucleic acid construct, for example an expression construct comprising a fusion protein nucleic acid sequence, is introduced into the host cell using a vehicle, or vector, for transferring genetic material. Vectors for transferring genetic material to cells are well known to those of skill in the art and include, for example, plasmids, artificial chromosomes, and viral vectors. Methods for the construction of nucleic acid constructs, including expression constructs comprising constitutive or inducible heterologous promoters, knockout and knockdown constructs, as well as methods and vectors for the delivery of a nucleic acid or nucleic acid construct to a cell are well known to those of skill in the art, and are described, for example, in J. Sambrook and D. Russell, Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press; 3rd edition (Jan. 15, 2001); David C. Amberg, Daniel J. Burke; and Jeffrey N. Strathern, Methods in Yeast Genetics: A Cold Spring Harbor Laboratory Course Manual, Cold Spring Harbor Laboratory Press (April 2005); John N. Abelson, Melvin I. Simon, Christine Guthrie, and Gerald R. Fink, Guide to Yeast Genetics and Molecular Biology, Part A, Volume 194 (Methods in Enzymology Series, 194), Academic Press (Mar. 11, 2004); Christine Guthrie and Gerald R. Fink, Guide to Yeast Genetics and Molecular and Cell Biology, Part B, Volume 350 (Methods in Enzymology, Vol 350), Academic Press; 1st edition (Jul. 2, 2002); Christine Guthrie and Gerald R. Fink, Guide to Yeast Genetics and Molecular and Cell Biology, Part C, Volume 351, Academic Press; 1st edition (Jul. 9, 2002); Gregory N. Stephanopoulos, Aristos A. Aristidou and Jens Nielsen, Metabolic Engineering: Principles and Methodologies, Academic Press; 1 edition (Oct. 16, 1998); and Christina Smolke, The Metabolic Pathway Engineering Handbook: Fundamentals, CRC Press; 1 edition (Jul. 28, 2009), all of which are incorporated by reference herein.

Phylogenetic Analysis

[0081] The present disclosure also provides methods of selecting a nif cluster of a donor bacterium that is compatible with a host bacterium. The methods involve performing a phylogenetic analysis for the donor bacterium and the host bacterium.

[0082] A phylogenetic analysis is a method of estimating the evolutionary relationships. In molecular phylogenetic analysis, the sequence of a common gene or protein can be used to assess the evolutionary relationship of species. In some embodiments, phylogenetic analysis is performed based on the rRNA (e.g., the full-length 16S rRNA gene) sequences. These sequence include e.g., K. oxytoca, BWI76_05380; A. vinelandii, Avin_55000; R. sphaeroides, DQL45_00005; Cyanothece ATCC51142, cce_RNA045; A. brasilense, AMK58_25190; R. palustris, RNA_55; P. protegens, PST_0759; Paenibacillus sp. WLY78, JQ003557. In some embodiments, a multiple sequence alignment can be generated using MUSCLE (Edgar, R. C. J. N. a. r. MUSCLE: multiple sequence alignment with high accuracy and high throughput. 32, 1792-1797 (2004)). A phylogenetic tree is then constructed using the Jukes-Cantor distance model and UPGMA as a tree build method.

[0083] As shown in FIGS. 30A and 30B, the phylogenetic closeness has a predictive power for nitrogenase activity of transferring a nif cluster in a new host. In some embodiments, the host bacterium and the donor bacterium are in the same genus, family, order, or class. In some embodiments, the donor bacterium is selected from Klebsiella, Pseudomonas, Azotobacter, Gluconacetobacter, Azospirillum, Azorhizobium, Rhodopseudomonas, Rhodobacter, Cyanothece, or Paenibacillus genus.

[0084] In some embodiments, the evolutionary distance based on the phylogenetic analysis between the donor bacterium and the host bacterium is less than a reference value. For example, the reference value is 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, or 0.1% substitutions per site in 16S ribosomal RNA gene sequence. In some embodiments, the reference value is 500, 400, 300, 200, 100, 50, or 10 million years on the phylogenetic tree.

[0085] The methods can also involve transferring the nif cluster to the host bacterium and determining the nitrogenase activity.

Genetically Modified Plants

[0086] In some embodiments, this disclosure features genetically-modified plant cells and plants (e.g., genetically-modified cereal plants or cells) comprising at least one recombinant nucleic acid construct described herein. In some embodiments, a nucleic acid construct can encode, for example, a chemical signal synthesis peptide, operably linked in sense orientation to one or more regulatory regions. In some embodiments, the chemical signal synthesis peptide is an opine biosynthetic polypeptide (e.g., from A. tumefaciens) such as octopine synthase or nopaline synthase. In some embodiments, the chemical signal synthesis peptide can produce a chemical signal, which the genetically engineered bacterium can respond. It will be appreciated that because of the degeneracy of the genetic code, a number of nucleic acids can encode a particular opine biosynthetic polypeptide; i.e., for many amino acids, there is more than one nucleotide triplet that serves as the codon for the amino acid. Thus, codons in the coding sequence for a given opine biosynthetic polypeptide can be modified such that expression in a particular plant species is obtained, using appropriate codon bias tables for that species.

[0087] In some cases, the regulatory region is a constitutive promoter. In some cases, the regulatory region is an inducible promoter. In some cases, the regulatory region is a root-active promoter that can confer transcription in root tissue, e.g., root endodermis, root epidermis, or root vascular tissues. In some embodiments, root-active promoters can include the root-specific subdomains of the CaMV 35S promoter (Lam et al., Proc. Natl. Acad. Sci. USA, 86:7890-7894 (1989)), root cell specific promoters of Conkling et al., Plant Physiol., 93:1203-1211 (1990), or the tobacco RD2 promoter.

[0088] As described herein, a cereal plant or plant cell can be transformed by having a nucleic acid construct integrated into its genome, i.e., can be stably transformed. Stably transformed cells typically retain the introduced nucleic acid with each cell division. A plant or plant cell can also be transiently transformed such that the construct is not integrated into its genome. Transiently transformed cells typically lose all or some portion of the introduced nucleic acid construct with each cell division such that the introduced nucleic acid cannot be detected in daughter cells after a sufficient number of cell divisions. Both transiently transformed and stably transformed transgenic plants and plant cells can be useful in the methods described herein.

[0089] Genetically modified plant cells used in methods described herein can constitute part or all of a whole plant. Such plants can be grown in a manner suitable for the species under consideration, either in a growth chamber, a greenhouse, or in a field. As used herein, a genetically modified plant also refers to progeny of an initial engineered plant provided the progeny inherits the construct. Seeds produced by a modified plant can be grown and then selfed (or outcrossed and selfed) to obtain seeds homozygous for the nucleic acid construct.

[0090] Modified plants can be grown in suspension culture, or tissue or organ culture. When using solid medium, modified plant cells can be placed directly onto the medium or can be placed onto a filter that is then placed in contact with the medium. When using liquid medium, modified plant cells can be placed onto a flotation device, e.g., a porous membrane that contacts the liquid medium. A solid medium can be, for example, Murashige and Skoog (MS) medium containing agar and a suitable concentration of an auxin, e.g., 2,4-dichlorophenoxyacetic acid (2,4-D), and a suitable concentration of a cytokinin, e.g., kinetin.

[0091] When transiently transformed plant cells are used, a reporter sequence encoding a reporter polypeptide having a reporter activity can be included in the transformation procedure and an assay for reporter activity or expression can be performed at a suitable time after transformation. A suitable time for conducting the assay typically is about 1-21 days after transformation, e.g., about 1-14 days, about 1-7 days, or about 1-3 days. The use of transient assays is particularly convenient for rapid analysis in different species, or to confirm expression of a polypeptide whose expression has not previously been confirmed in particular recipient cells.

[0092] Techniques for introducing nucleic acids into plants are known and include, without limitation, Agrobacterium-mediated transformation, viral vector-mediated transformation, electroporation and particle gun transformation, e.g., U.S. Pat. Nos. 5,538,880; 5,204,253; 6,329,571 and 6,013,863. If a cell or cultured tissue is used as the recipient tissue for transformation, plants can be regenerated from transformed cultures if desired, by techniques known to those skilled in the art.

[0093] A population of modified plants can be screened and/or selected for those members of the population that produce as described chemical signal (e.g., opine) at a desired location (e.g., in the roots) as conferred by expression of the transgene. For example, a population of progeny of a single transformation event can be screened for those plants having a desired level of expression of a polypeptide or nucleic acid.

Control of Nitrogenase Activity

[0094] In some embodiments, the disclosure provides a genetically engineered bacterium that contains a regulatory sequence or a genetic sensor that regulates the nitrogenase activity in response to a chemical signal (e.g., an environmental signal or artificial signal). In some embodiments, the chemical signal can be an environmental signal such as ammonia, IPTG, or oxygen. In some embodiments, the nif cluster is placed under the control of a genetic sensor that can respond to the chemical signal. In some embodiments, the genetic sensor can respond to biocontrol agents or components of added fertilizer and other treatments (e.g., DAPG). In some embodiments, the genetic sensor can respond to root exudates from a plant, including e.g., sugar such as arabinose, hormones such as salicylic acids, flavonoids such as naringenin, antimicrobials such as vanillic acid, and various chemicals that can remodel the microbial community (e.g., cuminic acid). In some embodiments, the genetic sensor can respond to chemicals released by other bacteria including e.g., 3,4-dihydroxybenzoic acid (DHBA), 3OC6HSL or 3OC14HSL.

[0095] In some embodiments, sensors for chemicals are used to construct controllers. In some embodiments, a "Marionette" strain of E. coli, which includes sensors for e.g., vanillic acid, DHBA, cuminic acid, 3OC6HSL and 3OC14HSL in the genome, is used to host the nif cluster. In some embodiments, the output promoter of a sensor is used to express T7 RNA polymerase. In some embodiments, the arabinose and naringenin sensors are used to express NifA, which leads to the induction of the nifH promoter and nitrogenase activity. In some embodiments, the arabinose and naringenin sensors are used to express NifA, which leads to the induction of the nifH promoter and nitrogenase activity in P. protegens Pf-5. In some embodiments, the DAPG sensor is used to drive T7 RNAP, which then induces nitrogenase activity. In some embodiments, the DAPG sensor is used to drive T7 RNAP, which then induces nitrogenase activity in R. sp. IRBG74. In some embodiments, the salicylic acid sensor is used to control NifA.sup.L94Q/D95Q/RpoN expression, which then activates nitrogenase activity. In some embodiments, the salicylic acid sensor is used to control NifA.sup.L94Q/D95Q/RpoN expression, which then activates nitrogenase activity in A. caulinodans.

[0096] In some embodiments, a plant is engineered to release an orthogonal chemical signal that can be sensed by a corresponding engineered bacterium. This would have the benefit of only inducing nitrogenase in the presence of the engineered crop. In some embodiments, legumes and Arabidopsis are engineered to produce opines, including nopaline and octopine. In some embodiments, an engineered bacterium contains sensors for nopaline and octopine. In some embodiments, an engineered bacterium contains the LysR-type transcriptional activators OccR (octopine) and NocR (nopaline) and their corresponding promoters. In some embodiments, sensors for nopaline and octopine are used to control the expression of NifA.sup.L94Q/D95Q/RpoN, which then activates nitrogenase activity.

[0097] The present disclosure also provides methods of selecting a nif cluster or a regulatory element for the nif cluster. The methods involve calculation of genetic-part strengths based on sequencing data. In some embodiments, RNA-seq and Ribosome-footprint profiling is carried out according to the method described herein. In some embodiments, to generate the RNA-seq read profile for each nif cluster, the raw trace profiles can be multiplied by e.g., at least or about 10.sup.5, 10.sup.6, 10.sup.7, 10.sup.8, or 10.sup.9 and normalized by respective total reads from coding sequences of each species. In some embodiments, the mRNA expression level of each gene is estimated using total sequencing reads mapped onto the gene, representing fragments per kilobase of transcript per million fragments mapped units (FPKM).

[0098] In some embodiments, the activity of a promoter is defined as the change in RNAP flux .delta.J around a transcription start site x.sub.tss. In some embodiments, the promoter strength or the regulatory element strength is calculated using the below equation:

.delta. .times. J = .gamma. n .function. [ i = x tss + 1 x tss + 1 + n .times. m .function. ( i ) - i = x tss - 1 x 0 - 1 - n .times. m .function. ( i ) ] ##EQU00002##

where m(i) is the number of transcripts at each position i from the FPKM-normalized transcriptomic profiles, .gamma.=0.0067 s.sup.-1 is the degradation rate of mRNA and n is the window length before and after x.sub.tss. In some embodiments, the window length is set to ten. In some embodiments, the Ts is defined as the fold-decrease in transcription before and after a terminator, which can be quantified from the FPKM-normalized transcriptomic profiles as:

T s = i = x 1 + 1 x 1 + n .times. m .function. ( i ) i = x 0 - 1 x 0 - n .times. m .function. ( i ) ##EQU00003##

where x.sub.0 and x.sub.1 are the beginning and end positions of the terminator part, respectively. The translation efficiency was calculated by dividing the ribosome density by the FPKM.

Definition

[0099] As used herein, the equivalent terms "expression" or "gene expression" are intended to refer to the transcription of a DNA molecule into RNA, and the translation of such RNA into a polypeptide.

[0100] As used herein, a "gene cluster" refers to a set of two or more genes that encode gene products. As used herein, a "nif gene cluster" refers to a set of two or more genes that encode nitrogen fixation genes.

[0101] "Exogenous" with respect to genes indicates that the nucleic acid or gene is not in its natural (native) environment. For example, an exogenous gene can refer to a gene that is from a different species. In contrast, "endogenous" with respect to genes indicates that the gene is in its native environment. As used herein, the terms "endogenous" and "native" are used interchangeably.

[0102] As used herein, the term "delete" or "deleted" refers to the removal of a gene (e.g. endogenous gene) from a sequence or cluster. As used herein, the term "alter" or "altered" refers to the modification of one or more nucleotides in a gene or the deletion of one or more base pairs in a gene. This alteration may render the gene dysfunctional. Herein, ".DELTA.nifA" refers to a strain or cluster within which NifA was deleted or altered. Method of deletion and alteration, in the context of genes, are known in the art.

[0103] As used herein, the term "chemical signals" refers to chemical compounds. Any substance consisting of two or more different types of atoms (chemical elements) in a fixed stoichiometric proportion can be termed a chemical compound. Chemical signals can be synthetic or natural chemical compounds. In some embodiments of the present invention, a bacterium of the present disclosure or a sensor of the present disclosure is under the control of a chemical signal. In some embodiments, the signal is a native biological signal (e.g. root exudate, biological control agent, etc.). In some embodiments, the chemical signal is a quorum sensing signal from the bacterium. Non-limiting examples of chemical signals include root exudates (as defined below), biocontrol agents (as defined below), phytohormones, vanillate, IPTG, aTc, cuminic acid, DAPG, and salicylic acid, 3,4-dihydroxybenzoic acid, 3OC6HSL and 3OC14HSL.

[0104] As used herein, the term "root exudate" refers to chemicals secreted or emitted by plant roots in response to their environment. These allow plant to manipulate or alter their immediate environment, specifically their rhizosphere. Root exudates are a complex mixture of soluble organic substances, which may contain sugars, amino acids, organic acids, enzymes, and other substances. Root exudates include, but are not limited to, ions, carbon-based compounds, amino acids, sterols, sugars, hormones (phytohormones), flavonoids, antimicrobials, and many other chemical compounds. The exudates can serve as either positive regulators or negative regulators.

[0105] As used herein, the term "phytohormone" refers plant hormones and they are any of various hormones produced by plants that influence process such as germination, growth, and metabolism in the plant.

[0106] As used herein, the term "vanillate" refers to a methoxybenzoate that is the conjugate base of vanillic acid. It is a plant metabolite.

[0107] Biological control or biocontrol is a method of controlling pests such as insects, mites, weeds and plant diseases using other organisms. Natural enemies of insect pests, also known as biological control agents, include predators, parasitoids, pathogens, and competitors. Biological control agents of plant diseases are most often referred to as antagonists. Biological control agents of weeds include seed predators, herbivores and plant pathogens. The inducible clusters or promoters of the present invention may be modulated by a secretion of (or chemical otherwise associated with) a biological control agent. Herein, that is referred to as a "biocontrol agent".

[0108] Without further elaboration, it is believed that one skilled in the art can, based on the above description, utilize the present invention to its fullest extent. The following specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever. All publications cited herein are incorporated by reference for the purposes or subject matter referenced herein.

EXAMPLES

[0109] Herein, inducible nitrogenase activity is engineered in two cereal endophytes (Azorhizobium caulinodans ORS571 and Rhizobium sp. IRBG74) and the epiphyte Pseudomonas protegens Pf-5, a maize seed inoculant. For each organism, different strategies are taken to eliminate ammonium repression and place nitrogenase expression under the control of agriculturally-relevant signals, including root exudates, biocontrol agents, and phytohormones. The present disclosure demonstrates that Rhizobium sp. (e.g., IRBG74) can be engineered to fix nitrogen under free living conditions, inter alia, by transferring either a nif cluster from Rhodobacter or Klebsiella. For P. protegens Pf-5, the transfer of an inducible cluster from Azotobacter vinelandii yields the highest ammonia and oxygen tolerance. Collectively, data from the transfer of 12 nif gene clusters between diverse species (including E. coli and 12 additional Rhizobia) help identify the barriers that must be overcome to engineer a bacterium to deliver a high nitrogen flux to a cereal crop and provide a solution such that Rhizobium can be engineered to fix nitrogen under free living conditions.

Materials and Methods

[0110] Bacterial Strains and Growth Media.

[0111] All bacterial strains and their derivatives used in this study are listed in Table 2. E. coli DH10-beta (New England Biolabs, MA, Cat #C3019) was used for cloning. E. coli K-12 MG1655 was used for the nitrogenase assay. P. protegens Pf-5 was obtained from the ATCC (BAA-477). Strains used in this study are listed in Table 3. For rich media, LB medium (10 g/L tryptone, 5 g/L yeast extract, 10 g/L NaCl), LB-Lennox medium (10 g/L tryptone, 5 g/L yeast extract, 5 g/L NaCl), and TY medium (5 g/L tryptone, 3 g/L yeast extract, 0.87 g/L CaCl.sub.2.2H.sub.2O) were used. For minimal media, BB medium (0.25 g/L MgSO.sub.4.7H.sub.2O, 1 g/L NaCl, 0.1 g/L CaCl.sub.2.2H.sub.2O, 2.9 mg/L FeCl.sub.3, 0.25 mg/L Na.sub.2MoO.sub.4.2H.sub.2O, 1.32 g/L NH.sub.4CH.sub.3CO.sub.2, 25 g/L Na.sub.2HPO.sub.4, 3 g/L KH.sub.2PO.sub.4 pH [7.4]), UMS medium (0.5 g/L MgSO.sub.4.7H.sub.2O, 0.2 g/L NaCl, 0.375 mg/L EDTA-Na.sub.2, 0.16 ZnSO.sub.4.7H.sub.2O, 0.2 mg/L Na.sub.2MoO.sub.4.2H.sub.2O, 0.25 mg/L H.sub.3BO.sub.3, 0.2 mg/L MnSO.sub.4.H.sub.2O, 0.02 mg/L CuSO.sub.4.5H.sub.2O, 1 mg/L CoCl.sub.2.6H.sub.2O, 75 mg/L CaCl.sub.2.2H.sub.2O, 12 mg/L FeSO.sub.4.7H.sub.2O, 1 mg/L thiamine hydrochloride 2 mg/L D-pantothenic acid hemicalcium salt, 0.1 mg/L biotin, 87.4 mg/L K.sub.2HPO, 4.19 g/L MOPS pH [7.0]), and Burk medium (0.2 g/L MgSO.sub.4.7H.sub.2O, 73 mg/L CaCl.sub.2.2H.sub.2O, 5.4 mg/L FeCl.sub.3.6H.sub.2O, 4.2 mg/L Na.sub.2MoO.sub.4.2H.sub.2O, 0.2 g/L KH.sub.2PO.sub.4, 0.8 g/L K.sub.2HPO.sub.4 pH [7.4]) were used. Antibiotics were used at the following concentrations (.mu.g/mL): E. coli (kanamycin, 50; spectinomycin, 100; tetracycline, 15; gentamicin, 15). P. protegens Pf-5 (kanamycin, 30; tetracycline, 50; gentamicin, 15; carbenicillin, 50). R. sp. IRBG74 (neomycin, 150; gentamicin, 150; tetracycline, 10; nitrofurantoin, 10). A. caulinodans (kanamycin, 30; gentamicin, 15; tetracycline, 10; nitrofurantoin, 10). Chemicals including inducers used in this study are listed in Table 7.

[0112] Strain Construction.

[0113] In order to increase transformation efficiency in R. sp. IRBG74, a type-I restriction modification system was inactivated by deleting hsdR, which encodes a restriction enzyme for foreign DNA (this strain was the basis for all experiments) (Ferri, L., Gori, A., Biondi, E. G., Mengoni, A. & Bazzicalupo, M. J. P. Plasmid electroporation of Sinorhizobium strains: The role of the restriction gene hsdR in type strain Rm1021. 63, 128-135 (2010)). A sacB markerless insertion method was utilized to allow replacements of a native locus with synthetic parts by homologous recombination. Two homology arms of -500 bp flanking the hsdR gene were amplified by PCR, cloned and yielded a suicide plasmid pMR-44. The suicide plasmid was mobilized into R. sp. IRBG74 by triparental mating. Single-crossover recombinants were selected for resistance to gentamicin and subsequently grown and plated on LB plates supplemented with 15% sucrose to induce deletion of the vector DNA part containing the counter selective marker sacB which converts sucrose into a toxic product (levan). Two native nif gene clusters encompassing nifHDKENX (genomic location 219.579-227, 127) and nifSW-fixABCX-nifAB-fdxN-nifTZ (genomic location 234, 635-234, 802) of R. sp. IRBG74 were sequentially deleted using pMR45-46. To increase genetic stability recA gene was deleted using the plasmid pMR47. The R. sp. IRBG74 .DELTA.nif, hsdR, recA strain was the basis for all experiments unless indicated otherwise. Two homology arms of .about.900 bp flanking the nifA gene were amplified by PCR, cloned and yielded a suicide plasmid pMR-47 to generate nifA deletion in A. caulinodans ORS571, The suicide plasmid pMR47 in E. coli was mobilized into A. caulinodans by triparental mating. Single-crossover recombinants were selected for resistance to gentamicin and subsequently grown and plated on plain TY plates supplemented with 15% sucrose to induce deletion of the vector DNA part. All markerless deletions were confirmed by gentamicin sensitivity and diagnostic PCR. A list of the mutant strains is provided in Table 3.

[0114] Plasmid System.

[0115] Plasmids with the pBBR1 origin were derived from pMQ131 and pMQ132. Plasmids with the pRO1600 origin were derived from pMQ80. Plasmids with the RK2 origin were derived from pJP2. Plasmids with the RSF1010 origin were derived from pSEVA651. Plasmids with the IncW origin were derived from pKT249. Plasmids used in this study are provided in Table 4.

[0116] Phylogenetic Analysis of Nif Clusters.

[0117] Phylogenetic analysis was performed based on the full-length 16S rRNA gene sequences (K. oxytoca, BWI76_05380; A. vinelandii, Avin_55000; R. sphaeroides, DQL45_00005; Cyanothece ATCC51142, cce_RNA045; A. brasilense, AMK58_25190; R. palustris, RNA_55; P. protegens, PST_0759; Paenibacillus sp. WLY78, JQ003557). A multiple sequence alignment was generated using MUSCLE (Edgar, R. C. J. N. a. r. MUSCLE: multiple sequence alignment with high accuracy and high throughput. 32, 1792-1797 (2004)). A phylogenetic tree was constructed using the Geneious software (R9.0.5) with the Jukes-Cantor distance model and UPGMA as a tree build method, with bootstrap values from 1,000 replicates.

[0118] Nif Cluster Construction.

[0119] To obtain large nif clusters on mobilizable plasmids that carry origin of transfer (oriT) for conjugative transfer of the plasmids, the genomic DNAs from K. oxytoca, P. stutzeri, A. vinelandii, A. caulinodans and R. sphaeroides were purified using Wizard genomic DNA purification kit, following the isolation protocol for gram negative bacteria (Promega, Cat #A1120). The genomic DNAs of Cyanothece ATCC51142, A. brasilense ATCC29729, R. palustris ATCC BAA-98, and G. diazotrophicus ATCC49037 were obtained from ATCC. Each nif cluster was amplified into several fragments (4-10 kb) with upstream and downstream 45 bp linkers at the 5' and 3' most end of the cluster by PCR with primer sets (Table 2) and assembled onto linearized E. coli-yeast shuttle vectors pMR-1 for E. coli and Rhizobia, and pMR-2 for P. protegens Pf-5 using yeast recombineering. For the nif cluster of Paenibacillus sp. WLY78, the DNA sequence information were gleaned from contig ALJV01 and the DNA of the nif cluster was synthesized by GeneArt gene synthesis (Thermo Fisher Scientific, MA) into four fragments that were used as templates for PCR amplification and assembly. Amplified fragments from two to eight (Table 2) were assembled with a linearized vector into a single large plasmid by one-pot yeast assembly procedure(Shanks, R. M. et al. Saccharomyces cerevisiae-based molecular tool kit for manipulation of genes from gram-negative bacteria. 72, 5027-5036 (2006)). Once assembled, the nif cluster-plasmids were isolated from yeast using Zymoprep Yeast Miniprep kit (Zymo Research Cat #D2004) and transformed into E. coli. The purified plasmid was isolated from E. coli and sequenced to verify the correct assembly and sequence (MGH CCIB DNA Core facility, Cambridge, Mass.). E. coli containing a mutation-free plasmid were stored for further experiments. Plasmids containing nif clusters are provided in Table 4.

[0120] Construction of Refactored Nif v3.2.

[0121] The six transcriptional units (nifHDKTY, nifENX, nifJ, nifBQ, nifF, nifUSVWZM) were amplified from the plasmid pMR-3 that harbors the native Klebsiella nif cluster. Each unit was divided onto six level-1 module plasmids where the nif genes are preceded by a terminator. T7 promoter wild-type or T7 promoter variant PT7.P2 was placed between a terminator and the first gene of the transcriptional unit. Assembly linkers (.about.45 bp) were placed at both ends of the units. The level-1 plasmids (pMR32-37) were provided in Table 4 and 5. Each of the six plasmids was linearized by digestion with restriction enzymes and assembled with a linearized pMR-1 or pMR-2 vector into a single large plasmid by one-pot yeast assembly procedure, yielding pMR38 and pMR39.

[0122] Transformation.

[0123] Electroporation was used to transfer plasmids into P. protegens Pf-5. A single colony was inoculated in 4 mL of LB and grown for 16 h at 30.degree. C. with shaking at 250 rpm. The cell pellets were washed twice with 2 mL of 300 mM sucrose and dissolved in 100 .mu.l of 300 mM sucrose at RT. A total of 50-100 ng DNA was electroporated and recovered in 1 mL of LB media for 1 h before plating on selective LB plates. Triparental mating was used to transfer DNA from E. coli to Rhizobia. An aliquot of 40 .mu.l of late-log phase (OD.sub.600.about.0.6) donor cells and 40 .mu.l of late-log phage helper cells containing pRK7013 were mixed with 200 .mu.l of late-log phase (OD.sub.600.about.0.8) recipient Rhizobia cells and washed in 200 .mu.l of TY medium. Mating was initiated by spotting 20 .mu.l of the mixed cells on TY plates and incubated at 30.degree. C. for 6 h. The mating mixtures were plated on TY medium supplemented with nitrofurantoin to isolate Rhizobia transconjugants.

[0124] Construction and Characterization Genetic Parts for Rhizobia.

[0125] Genetic part libraries were built on a pBBR1-ori plasmid pMR-1 using Gibson assembly (New England Biolabs, Cat #E2611). The fluorescence proteins, GFPmut3b and mRFP1, were used as reporters. The Anderson promoter library (Anderson, J. et al. BglBricks: A flexible standard for biological part assembly. 4, 1 (2010)) on the BioBricks Registry were utilized for the characterization of constitutive promoters (FIGS. 11A-11C). To characterize inducible promoters, a regulator protein is constitutively expressed by the PlacIq promoter, and GFP expression is driven by a cognate inducible promoter from the opposite direction, facilitating replacement of the reporter with gene of interest (e.g., T7 RNAP and nifA) and transfer of the controller unit across different plasmid backbones for diverse microbes. The following combinations of cognate regulators and inducible promoters were characterized. IPTG inducible LacI-A1lacO1, DAPG inducible Ph1F-PPh1, aTc inducible TetR-PTet, 3OC6HSL inducible LuxR-P.sub.Lux, salicylic acid inducible NahR-P.sub.Sal, and cuminic acid inducible CymR-P.sub.Cym systems were optimized for R. sp. IRBG74 (FIG. 14). Opine inducible OccR-P.sub.occ, and nopaline inducible NocR-Pnoc systems were optimized for A. caulinodans (FIGS. 20A-20F and Tables 4 and 5). For RBS characterization, an IPTG-inducible GFP expression plasmid pMR-40 was used and GFP was expressed to the highest levels with 1 mM IPTG (FIGS. 12A-12B). RBS library for GFP was designed using the RBS library calculator at the highest-resolution mode, and the 3' end of the 16S rRNA sequences were adjusted according to the species (3'-ACCTCCTTC-5' for R. sp. IRBG74). Terminators for T7 RNAP were characterized by placing a terminator between two fluorescence reporters expressed from a single T7 wild-type promoter located upstream of the first fluorescence protein GFP. The expression of the two fluorescence proteins is enabled by the controller strain MR18 encoding the IPTG-inducible T7 RNAP system by 1 mM IPTG (FIGS. 13A-13B). The terminator strength (Ts) was determined by normalizing fluorescence levels of a terminator construct by a reference construct pMR-66 where a 40 bp spacer was placed between the reporters. All genetic parts for Rhizobia were characterized as follows. Single colonies were inoculated into 0.5 ml TY supplemented with antibiotics in 96-deepwell plates (USA Scientific, Cat #18962110) and grown overnight at 30.degree. C., 900 rpm in a Multitron incubator (INFORS HT, MD). 1.5 .mu.l of overnight cultures was diluted into 200 .mu.l of TY with antibiotics and appropriate inducers in 96-well plates (Thermo Scientific, Cat #12565215) and incubated for 7 h at 30.degree. C., 1,000 rpm in an ELMI DTS-4 shaker (ELMI, CA). After growth, 8 .mu.l of culture sample was diluted into 150 .mu.l PBS with 2 mg/mL kanamycin for flow cytometry analysis. Plasmids and genetic parts are listed in Table 4 and 5.

[0126] Construction and Characterization Genetic Parts for P. protegens.

[0127] Genetic part libraries were built on a pRO1600-ori plasmid pMR-2 using Gibson assembly (New England Biolabs, Cat #E2611). The fluorescence proteins, GFPmut3b and mRFP1 were used as reporters. The Anderson promoter library on the BioBricks Registry were utilized for the characterization of constitutive promoters (FIGS. 11A-11C). The following combinations of cognate regulators and inducible promoters were characterized. IPTG inducible LacI-P.sub.tac, DAPG inducible Ph1F-P.sub.Phl, aTc inducible TetR-P.sub.Tet, 3OC6HSL inducible LuxR-P.sub.Lux, arabinose inducible AraC-P.sub.BAD, cuminic acid inducible CymR-P.sub.Cym, and naringenin inducible FdeR-P.sub.Fde were optimized (FIGS. 15A-15C). For RBS characterization, an arabinose-inducible GFP expression plasmid pMR-65 was used and GFP was expressed with 1 mM IPTG (FIGS. 12A-12B). RBS library for GFP was designed using the RBS library calculator at the highest-resolution mode, and the 3' end of the 16S rRNA sequences were adjusted according to the species (3'-ACCTCCTTA-5' for P. protegens Pf-5). Terminators for T7 RNAP were characterized by placing a terminator between two fluorescence reporters expressed from a single T7 wild-type promoter located upstream of the first fluorescence protein GFP. The expression of the two fluorescence proteins is enabled by an IPTG-inducible T7 RNAP expression system of the controller strain MR7 (FIGS. 13A-13B). All genetic parts for P. protegens Pf-5 were characterized as follows. Single colonies were inoculated into 1 ml LB supplemented with antibiotics in 96-deepwell plates (USA Scientific, Cat #18962110) and grown overnight at 30.degree. C., 900 rpm in a Multitron incubator (INFORS HT, MD). 0.5 .mu.l of overnight cultures was diluted into 200 .mu.l of LB with antibiotics and appropriate inducers in 96-well plates (Thermo Scientific, Cat #12565215) and incubated for 7 h at 30.degree. C., 1,000 rpm in an ELMI DTS-4 shaker (ELMI, CA). After growth, 10 .mu.l of culture sample was diluted into 150 .mu.l PBS with 2 mg/mL kanamycin for flow cytometry analysis. Plasmids and genetic parts are listed in Tables 4 and 5.

[0128] Genomic Integration and Characterization of Controllers.

[0129] The mini-Tn7 insertion system was used to introduce a controller into the genome of P. protegens Pf-5. The IPTG-inducible T7 RNAP expression system and a tetracycline resistant marker tetA was placed between two Tn7 ends (Tn7L and Tn7R). The controller plasmid pMR-85 was introduced into P. protegens Pf-5 by double transformation with pTNS3 encoding the TnsABCD transposase. A genomically-integrated controller located 25 bp downstream of the stop codon of glmS was confirmed by PCR and sequencing. A markerless insertion method using homologous recombination was employed in R. sp. IRBG74. A controller encoding inducible T7 RNAP system flanked by two homology fragments that enables the replacement of recA was cloned into a suicide plasmid. These controller plasmids (IPTG-inducible, pMR82-84; DAPG-inducible, pMR85) in E. coli was mobilized into R. sp. IRBG74 MR18 (.DELTA.hsdR. .DELTA.nif) by triparental mating, generating the controller strains (MR19, 20, 21 and 22, respectively). The controller integration in the genome was confirmed by gentamicin sensitivity and diagnostic PCR. All controllers were characterized in a manner identical to that described in genetic part characterization.

[0130] Construction and Characterization of Marionette-Based Controllers.

[0131] To regulate nitrogenase expression in the E. coli Marionette MG1655, the yfp in the 12 reporter plasmids was replaced with T7 RNAP while keeping other genetic parts (e.g., promoters and RBSs) unchanged (FIGS. 28A-28C). The reporter plasmid pMR-120 in which gfpmut3b is fused to the PT7(P2) promoter (FIGS. 28A-28C) was co-transformed to analyze the response functions of each of the 12 T7 RNAP controller plasmids. To characterize controllers, single colonies were inoculated into 1 ml LB supplemented with antibiotics in 96-deepwell plates (USA Scientific, Cat #18962110) and grown overnight at 30.degree. C., 900 rpm in a Multitron incubator (INFORS HT, MD). 0.5 .mu.l of overnight cultures was diluted into 200 .mu.l of LB with antibiotics and appropriate inducers in 96-well plates (Thermo Scientific, Cat #12565215) and incubated for 6 h at 30.degree. C., 1,000 rpm in an ELMI DTS-4 shaker (ELMI, CA). After growth, 4 .mu.l of culture sample was diluted into 150 .mu.l PBS with 2 mg/mL kanamycin for flow cytometry analysis.

[0132] Flow Cytometry.

[0133] Cultures with fluorescence proteins were analyzed by flow cytometry using a BD Biosciences LSRII Forterssa analyzer with a 488 nm laser and 510/20-nm band pass filter for GFP and a 561 nm laser and 610/20 nm band pass filter for mCherry and mRFP1. Cells were diluted into 96-well plates containing phosphate buffered saline solution (PBS) supplemented with 2 mg/mL kanamycin after incubation. Cells were collected over 20,000 events which were gated using forward and side scatter to remove background events using FlowJo (TreeStar Inc., Ashland, Oreg.). The median fluorescence from cytometry histograms was calculated for all samples. The median autofluorescence was subtracted from the median fluorescence and reported as the fluorescence value in arbitrary unit (au).

[0134] Nitrogenase Assay (E. coli and K. oxytoca).

[0135] Cultures were initiated by inoculating a single colony into 1 mL of LB supplemented with appropriate antibiotics in 96-deepwell plates (USA Scientific, Cat #18962110) and grown overnight at 30.degree. C., 900 rpm in a Multitron incubator. 5 .mu.l of overnight cultures was diluted into 500 .mu.l of BB medium with 17.1 mM NH4CH3CO2 and appropriate antibiotics in 96-deepwell and incubated for 24 h at 30.degree. C., 900 rpm in a Multitron incubator. Cultures were diluted to an OD600 of 0.4 into 2 mL of BB medium supplemented with appropriate antibiotics, 1.43 mM serine to facilitate nitrogenase depression, and an inducer (if necessary) in 10 mL glass vials with PTFE-silicone septa screw caps (Supelco Analytical, Cat #SU860103). Headspace in the vials was replaced with 100% argon gas using a vacuum manifold. Acetylene freshly generated from CaC.sub.2 in a Burris bottle was injected to 10% (vol/vol) into each culture vial to begin the reaction. The acetylene reduction was carried out for 20 h at 30.degree. C. with shaking at 250 rpm in an Innova 44 shaking incubator (New Brunswick) to prevent cell aggregations, followed by quenching via the addition of 0.5 mL of 4 M NaOH to each vial.

[0136] Nitrogenase Assay (P. protegens Pf-5).

[0137] Cultures were initiated by inoculating a single colony into 1 mL of LB supplemented with appropriate antibiotics in 96-deepwell plates (USA Scientific, Cat #18962110) and grown overnight at 30.degree. C., 900 rpm in a Multitron incubator. 5 .mu.l of overnight cultures was diluted into 500 .mu.l of BB medium with 17.1 mM NH.sub.4CH.sub.3CO.sub.2 and appropriate antibiotics in 96-deepwell and incubated for 24 h at 30.degree. C., 900 rpm in a Multitron incubator. Cultures were diluted to an OD.sub.600 of 0.4 into 2 mL of BB medium supplemented with appropriate antibiotics, 1.43 mM serine and an inducer (if necessary) in 10 mL glass vials with PTFE-silicone septa screw caps. Headspace in the vials was replaced with 99% argon and 1% oxygen gas (Airgas, MA USA) using a vacuum manifold. Acetylene was injected to 10% (vol/vol) into each culture vial to begin the reaction. The acetylene reduction was carried out for 20 h at 30.degree. C. with shaking at 250 rpm, followed by quenching via the addition of 0.5 mL of 4 M NaOH to each vial.

[0138] Nitrogenase Assays (Rhizobia Strains).

[0139] Cultures were initiated by inoculating a single colony into 0.5 mL of TY medium supplemented with appropriate antibiotics in 96-deepwell plates (USA Scientific, Cat #18962110) and grown overnight at 30.degree. C., 900 rpm in a Multitron incubator. 5 .mu.l of overnight cultures was diluted into 500 .mu.l of UMS medium with 30 mM succinate, 10 mM sucrose, and 10 mM NH.sub.4C1 and appropriate antibiotics in 96-deepwell and incubated for 24 h at 30.degree. C., 900 rpm in a Multitron incubator. Cultures were diluted to an OD.sub.600 of 0.4 into 2 mL of UMS medium plus 30 mM succinate and 10 mM sucrose supplemented with appropriate antibiotics, 1.43 mM serine and an inducer (if necessary) in 10 mL glass vials with PTFE-silicone septa screw caps. Headspace in the vials was replaced with 99% argon and 1% oxygen gas using a vacuum manifold. Acetylene was injected to 10% (vol/vol) into each culture vial to begin the reaction. The acetylene reduction was carried out for 20 h at 30.degree. C. with shaking at 250 rpm, followed by quenching via the addition of 0.5 mL of 4 M NaOH to each vial.

[0140] Nitrogenase Assays (A. caulinodans and P. stutzeri).

[0141] Cultures were initiated by inoculating a single colony into 0.2 mL of TY medium supplemented with appropriate antibiotics in 96-deepwell plates and grown overnight at 37.degree. C. and 30.degree. C. for A. caulinodans and P. stutzeri, respectively, 900 rpm in a Multitron incubator. 5 .mu.l of overnight cultures was diluted into 500 .mu.l of UMS medium with 30 mM lactate and 10 mM NH.sub.4Cl and appropriate antibiotics in 96-deepwell and incubated for 24 h at 37.degree. C. and 30.degree. C. for A. caulinodans and P. stutzeri, respectively, 900 rpm in a Multitron incubator. Cultures were diluted to an OD.sub.600 of 0.4 into 2 mL of UMS medium plus 30 mM lactate supplemented with appropriate antibiotics and an inducer (if necessary) in 10 mL glass vials with PTFE-silicone septa screw caps. Headspace in the vials was replaced with 99% argon plus 1% oxygen gas using a vacuum manifold. Acetylene was injected to 10% (vol/vol) into each culture vial to begin the reaction. The acetylene reduction was carried out for 20 h at 30.degree. C. with shaking at 250 rpm, followed by quenching via the addition of 0.5 mL of 4 M NaOH to each vial.

[0142] Nitrogenase Assays (A. vinelandii).

[0143] Cultures were initiated by inoculating a single colony into 0.5 mL of Burk medium supplemented with appropriate antibiotics in 96-deepwell plates (USA Scientific, Cat #18962110) and grown overnight at 30.degree. C., 900 rpm in a Multitron incubator. 5 .mu.l of overnight cultures was diluted into 500 .mu.l of Burk medium with 17.1 mM NH4CH3CO2 and appropriate antibiotics in 96-deepwell and incubated for 24 h at 30.degree. C., 900 rpm in a Multitron incubator. Headspace in the vials was replaced with 97% argon and 3% oxygen gas (Airgas, MA USA) using a vacuum manifold. Acetylene was injected to 10% (vol/vol) into each culture vial to begin the reaction. The acetylene reduction was carried out for 20 h at 30.degree. C. with shaking at 250 rpm, followed by quenching via the addition of 0.5 mL of 4 M NaOH to each vial.

[0144] Nitrogenase Activity Assay in the Presence of Ammonium.

[0145] Following overnight incubation in minimal medium with a nitrogen source (described above), cultures were diluted to an OD.sub.600 of 0.4 in 2 mL of nitrogen-free minimal medium, 1.43 mM serine (for E. coli and P. protegens Pf-5) and an inducer (for inducible systems) in 10 mL glass vials with PTFE-silicone septa screw caps. Ammonium (17.1 mM NH.sub.4CH.sub.3CO.sub.2 for E. coli and P. protegens Pf-5 and 10 mM NH4Cl for Rhizobia) was added to a nitrogen-free minimal medium when testing ammonium tolerance of nitrogenase activity. Headspace in the vials was replaced with either 100% argon gas for E. coli, 99% argon plus 1% oxygen for Pseudomonas and Rhizobia using a vacuum manifold. Acetylene was injected to 10% (vol/vol) into each culture vial to begin the reaction. The acetylene reduction was carried out for 20 h at 30.degree. C. with shaking at 250 rpm followed by quenching via the addition of 0.5 mL of 4 M NaOH to each vial.

[0146] Nitrogenase Activity Assay at Varying Oxygen Levels.

[0147] Following overnight incubation in minimal medium with a nitrogen source (described above), cultures were diluted to an OD.sub.600 of 0.4 in 2 mL of minimal medium, 1.43 mM serine (for E. coli and P. protegens Pf-5), and an inducer (for inducible systems) in 10 mL glass vials with PTFE-silicone septa screw caps. The vial headspace was replaced with either 100% nitrogen gas for E. coli or 99% nitrogen plus 1% oxygen for P. protegens Pf-5 and A. caulinodans using a vacuum manifold. Cultures were incubated with shaking at 250 rpm at 30.degree. C. for 6 h and 9 h for P. protegens Pf-5 and A. caulinodans, respectively, after which oxygen concentrations in the headspace were recorded with the optical oxygen meter FireStingO2 equipped with a needle-type sensor OXF500PT (Pyro Science, Germany) After the induction period, no oxygen remained in the headspace for all species as confirmed by the oxygen meter. The initial oxygen levels in the headspace were adjusted by injecting pure oxygen via syringe into the headspace of the vials and stabilized with shaking at 250 rpm at 30.degree. C. for 15 m followed by the injection of acetylene to 10% (vol/vol) into each culture vial to begin the reaction and initial oxygen concentrations in the headspace were recorded concomitantly. The oxygen levels in the headspace were maintained around the setting points (<.+-.0.25% 02) while incubating at 250 rpm and 30.degree. C. by injecting oxygen every hour for 3 h with oxygen monitoring before and after oxygen spiking (FIGS. 26A-26B). The reactions were quenched after 3 h of incubation by the injection of 0.5 mL of 4 M NaOH to each vial using a syringe.

[0148] Ethylene Quantification.

[0149] Ethylene production was analyzed by gas chromatography using an Agilent 7890A GC system (Agilent Technologies, Inc., CA USA) equipped with a PAL headspace autosampler and flame ionization detector as follows. An aliquot of 0.5 mL headspace preincubated to 35.degree. C. for 30 s was injected and separated for 4 min on a GS-CarbonPLOT column (0.32 mm.times.30 m, 3 microns; Agilent) at 60.degree. C. and a He flow rate of 1.8 mL/min. Detection occurred in a FID heated to 300.degree. C. with a gas flow of 35 mL/min H2 and 400 mL/min air. Acetylene and ethylene were detected at 3.0 min and 3.7 min after injection, respectively. Ethylene production was quantified by integrating the 3.7 min peak using Agilent GC/MSD ChemStation Software.

[0150] Sample Preparation for RNA-Seq and Ribosome Profiling.

[0151] Cultures of K. oxytoca, E. coli, P. protegens Pf-5 or R. sp. IRBG74 were grown following the same protocol as used for nitrogenase activity assay (described above) with a few changes. Following overnight incubation in minimal medium with a nitrogen source, cultures were diluted to an OD.sub.600=0.4 in 25 mL of minimal medium (with an inducer, if needed) and antibiotics in 125 mL Wheaton serum vials (DWK Life Sciences, Cat #223748) with septum stoppers (Fisher Scientific, Cat #FB57873). The vial headspace was replaced with either 100% nitrogen gas for E. coli and K. oxytoca or 99% nitrogen plus 1% oxygen for P. protegens Pf-5 and R. sp. IRBG74 using a vacuum manifold. Cultures grown 6 h at 30.degree. C., 250 rpm were filtered onto a nitrocellulose filter 0.45 .mu.M pore size (Fisher Scientific, Cat #GVS1215305). Cell pellets were combined from three vials using a stainless-steel scoopula, followed by flash-frozen in liquid nitrogen. The frozen pellets were added to 650 .mu.l of frozen droplets of lysis buffer (20 mM Tris (pH 8.0), 100 mM NH.sub.4Cl, 10 mM MgCl.sub.2, 0.4% Triton X-100, 0.1% NP-40, 1 mM chloramphenicol and 100 U/mL DNase I) in prechilled 25 mL canister (Retsch, Germany, Cat #014620213) in liquid nitrogen and pulverized using TissueLyser II (Qiagen USA) with a setting at 15 Hz for 3 min for 5 times with intermittent cooling between cycles. The pellet was removed by centrifugation at 20,000 rcf at 4.degree. C. for 10 min and the lysate was recovered in the supernatant.

[0152] RNA-Seq Experiments.

[0153] RNA-seq and Ribosome-footprint profiling was carried out according to the method described earlier with a few modifications(Li, G.-W., Oh, E. & Weissman, J. S. J. N. The anti-Shine--Dalgarno sequence drives translational pausing and codon choice in bacteria. 484, 538 (2012); Li, G.-W., Burkhardt, D., Gross, C. & Weissman, J. S. Quantifying absolute protein synthesis rates reveals principles underlying allocation of cellular resources. Cell 157, 624-635 (2014)). The total RNA was isolated using the hot phenol-SDS extraction method. The rRNA fractions were determined and subtracted from the total using the MICROBExpress kit (Thermo Fisher Scientific, Cat #AM1905). The remaining mRNAs and tRNAs were fragmented by RNA fragmentation reagents (Thermo Fisher Scientific, Cat #AM8740) at 95.degree. C. for 1 m 45 s. RNA fragments (10-45 bp) were isolated from a 15% TBE-Urea polyacrylamide gel (Thermo Fisher Scientific, Cat #EC6885). The 3' ends of the RNA fragments were dephosphorylated using T4 polynucleotide kinase (1U/.mu.l, New England Biolabs, Cat #M0201S) in a 20 .mu.l reaction volume supplemented with 1 .mu.l of 20 U SUPERase. In at 37.degree. C. for 1 h, after which the denatured fragments (5 pmoles) were incubated at 80.degree. C. for 2 min and ligated to 1 .mu.g of the oligo (/5rApp/CTGTAGGCACCATCAAT/3ddc/, Integrated DNA technologies) (SEQ ID NO: 1) in a 20 .mu.l reaction volume supplemented with 8 .mu.l of 50% PEG 8000, 2 .mu.l of 10.times.T4 RNA ligase 2 buffer, 1 .mu.l of 200 U/.mu.l truncated K277Q T4 ligase 2 (New England Biolabs, Cat #M0351) and 1 .mu.l of 20 U/.mu.l of SUPERase. In (Invitrogen) at 25.degree. C. for 3 h. The ligated fragments (35-65 bp) were isolated from a 10% TBE-Urea polyacrylamide gel (Invitrogen, Cat #EC6875). cDNA libraries from the purified mRNA products were reverse-transcribed using Superscript III (Thermo Fisher Scientific, Cat #18080044) with oCJ485 primer (/5Phos/AGATCGGAAGAGCGTCGTGTAGGGAAAGAGTGT/iSp18/CAAGCAGAAGA CGGCATACGAGATATTGATGGTGCCTACAG (SEQ ID NO: 2, SEQ ID NO: 3)) at 50.degree. C. for 30 min and RNA products subsequently were hydrolyzed by the addition of NaOH at a final concentration of 0.1 M, followed by incubation at 95.degree. C. for 15 min. The cDNA libraries (125-150 bp) were isolated from on a 10% TBE-Urea polyacrylamide gel (Invitrogen, Cat #EC6875). The cDNA products were circularized in a 20 .mu.l reaction volume supplemented with 2 .mu.l of 10.times. CircLigase buffer, 1 .mu.l of 1 mM ATP, 1 .mu.l of 50 mM MnCl2 and 1 .mu.l of CircLigase (Epicenter, Cat #CL4115K) at 60.degree. C. for 2 h and heat-inactivated at 80.degree. C. for 10 min. 5 .mu.l of circularized DNA was amplified using Phusion HF DNA polymerase (New England Biolabs, Cat #M0530) with o231 primer (CAAGCAGAAGACGGCATACGA (SEQ ID NO: 4)) and indexing primers (AATGATACGGCGACCACCGAGATCTACACGATCGGAAGAGCACACGTCTGAACT CCAGTCACNNNNNNACACTCTTTCCCTACAC (SEQ ID NO: 5)) for 7 to 10 cycles. The amplified products (125-150 bp) were recovered from an 8% TBE-Urea polyacrylamide gel (Invitrogen, Cat #EC62152). The purified products were analyzed by BioAnalyzer (Agilent, CA USA) and sequenced with a sequencing primer (CGACAGGTTCAGAGTTCTACAGTCCGACGATC (SEQ ID NO: 6)) using an Illumina HiSeq 2500 with a rapid run mode. To generate the RNA-seq read profile for each nif cluster, the raw trace profiles are multiplied by 10.sup.7 and normalized by respective total reads from coding sequences of each species (K. oxytoca M5al, CP020657.1; E. coli MG1655, NC_000913.3; P. protegens Pf-5, CP000076; R. sp. IRBG74 HG518322, HG518323, HG518324 and an appropriate plasmid carrying a nif cluster). The mRNA expression level of each gene was estimated using total sequencing reads mapped onto the gene, representing fragments per kilobase of transcript per million fragments mapped units (FPKM).

[0154] Ribo-Seq Experiments.

[0155] 0.5 mg of RNA was diluted into 195 .mu.l of the lysis buffer including 0.5 U RNase inhibitor SUPERase. In (Invitrogen, Cat #AM2694), 5 mM CaCl2 and were treated with 5 .mu.l of 750 U of micrococcal nuclease (Sigma Aldrich, Cat #10107921001) at 25.degree. C. for 1 h to obtain ribosome-protected monosomes. The digestions were quenched by the addition of EGTA to a final concentration of 6 mM and then kept on ice before the isolation of monosomes. Subsequently, the monosome fraction was collected by sucrose density gradient (10-55% w/v) ultracentrifugation at 35,000 rpm for 3 h, followed by a hot phenol-SDS extraction to isolate ribosome-protected mRNA fragments. The mRNA fragments (15-45 bp) were isolated from a 15% TBE-Urea polyacrylamide gel. The 3' ends of the purified fragments were dephosphorylated and ligated to the modified oligo. cDNA libraries generated by Superscript III were circularized by CircLigase as described above. rRNA products were depleted by a respective biotinylated oligo mix for E. coli and P. protegens Pf-5.5 .mu.l of circularized DNA was amplified using Phusion HF DNA polymerase with o231 primer and indexing primers for 7 to 10 cycles. The amplified products (125-150 bp) were recovered from an 8% TBE-Urea polyacrylamide gel. The purified products were analyzed by BioAnalyzer and sequenced with a sequencing primer (CGACAGGTTCAGAGTTCTACAGTCCGACGATC (SEQ ID NO: 7)) using an Illumina HiSeq 2500 with a rapid run mode. Sequences were aligned to reference sequences using Bowtie 1.1.2 with the parameters--k1--m2--v1. A center-weighting approach was used to map the aligned footprint reads ranging from 22 to 42 nucleotides in length. To map P-site of ribosome from footprint reads, 11 nucleotides from the both ends were trimmed, and the remaining nucleotide were given the same score, normalized by the length of the center region. Aligned reads (10-45 nucleotides) were mapped to the reference with equal weight of each nucleotide. A Python 3.4 script was used to perform the mapping. To generate the Ribo-seq read profile for each nif cluster, the raw trace profiles are multiplied by 10.sup.8 and normalized by respective total reads from coding sequences of each species. To calculate the ribosome density of each gene, read densities were first normalized in the following ways: (i) The first and last 5 codons of the gene are excluded for the calculation to remove the effects of translation initiation and termination. (ii) A genome-wide read density profile was fitted to an exponential function and the density at each nucleotide on a given gene was corrected using this function. (iii) If the average read density on a gene is higher than 1, a 90% winsorization was applied to reduce the effect of outliers. The sum of normalized reads on a gene was normalized by the gene length and the total read densities on coding sequences to yield the ribosome density.

[0156] Calculation of Genetic Part Strengths Based On--Seq Data.

[0157] The activity of a promoter is defined as the change in RNAP flux .delta.J around a transcription start site x.sub.tss (Gorochowski, T. E. et al. Genetic circuit characterization and debugging using RNA-seq. 13, 952 (2017)). The promoter strength is calculated by

.delta. .times. J = .gamma. n .function. [ i = x tss + 1 x tss + 1 + n .times. m .function. ( i ) - i = x tss - 1 x 0 - 1 - n .times. m .function. ( i ) ] ( 1 ) ##EQU00004##

where m(i) is the number of transcripts at each position I from FPKM-normalized transcriptomic profiles, y=0.0067 s.sup.-1 is the degradation rate of mRNA, n is the window length before and after x.sub.tss. The window length is set to 10. The terminator strength T.sub.s is defined as the fold-decrease in transcription before and after a terminator, which can be quantified from FPKM-normalized transcriptomic profiles as

T s = i = x 1 + 1 x 1 + n .times. m .function. ( i ) i = x 0 - 1 x 0 - n .times. m .function. ( i ) ( 2 ) ##EQU00005##

where x.sub.0 and x.sub.1 are the beginning and end positions of the terminator part, respectively. Translation efficiency was calculated by dividing the ribosome density by the FPKM.

[0158] nifH Expression Analysis.

[0159] Complementation of NifA was tested using plasmid pMR-128 to 130 that contains the sfgfp fused to the nifH promoter in the A. caulinodans .DELTA.nifA mutant. The inducible NifA/RpoN expression was provided by the plasmid pMR-121 into which sfgfp driven by the nifH promoter was added to analyze nifH promoter activity, yielding pMR-131 (FIG. 29). The IPTG-inducible system in the plasmid pMR-124 was substituted with other inducible systems including the salicylic acid-inducible, nopaline-inducible and octopine-inducible systems, yielding pMR-125, 126, and 127, respectively. Each of the plasmids was mobilized into the A. caulinodans .DELTA.nifA mutant, which was grown following the same protocol as used for nitrogenase activity (described herein). Following overnight incubation in minimal medium with a nitrogen source, cultures were diluted to an OD.sub.600=0.4 in 2 mL of UMS medium plus 30 mM lactate, antibiotics and an inducer (for inducible systems) in 10 mL glass vials with PTFE-silicone septa screw caps. Headspace in the vials was replaced with 99% argon plus 1% oxygen using a vacuum manifold. The vials were incubated with shaking at 250 rpm at 30.degree. C. for 9 h, after which 10 .mu.l of cultures was diluted into 150 .mu.l PBS with 2 mg/mL kanamycin for flow cytometry analysis. To test activation of the nifH promoters by diverse NifA proteins, the plasmids pMR-51, 53, 88, 89 and 90 were introduced into E. coli MG1655 and the plasmids pMR-91, 92, 93, 94 and 95 to P. protegens Pf-5. The plasmid pMR-101 was used to provide inducible NifA expression by IPTG in E. coli. The controller encoding the IPTG-inducible NifA was inserted into the genome of P. protegens Pf-5 using the plasmids pMR-96, 97 and 98. The IPTG-inducible system of the NifA controller plasmid pMR-96 was replaced with the arabinose-inducible and the naringenin-inducible system, yielding pMR-99 and 100, respectively. The inducibility of nifH expression was assessed by the reporter plasmids pMR-105 to 107 and pMR102 to 104 or E. coli and P. protegens Pf-5, respectively. The controller plasmids were transformed into E. coli or P. protegens Pf-5 with the reporter plasmids. Following overnight incubation in minimal medium with a nitrogen source, cultures were diluted to an OD.sub.600=0.4 in 2 mL of BB medium, antibiotics and an inducer (for inducible systems) in 10 mL glass vials with PTFE-silicone septa screw caps. Headspace in the vials was replaced with either 100% argon for E. coli or 99% argon plus 1% oxygen for P. protegens Pf-5 using a vacuum manifold. The vials were incubated with shaking at 250 rpm at 30.degree. C. for 9 h, after which 10 .mu.l of cultures was diluted into 150 .mu.l PBS with 2 mg/mL kanamycin for flow cytometry analysis.

[0160] Sequence Alignment.

[0161] NifA sequences of R. sphaeroides 2.4.1 (RSP_0547) and A. caulinodans ORS571 (AZC_1049) were obtained from NCBI. NifA protein sequences were aligned with MUSCLE (https://www.ebi.ac.uk/Tools/msa/muscle/) with a default settings (FIG. 22).

[0162] Results

[0163] Performance of Native Nif Clusters in E. coli, P. Protegens Pf-5, and Symbiotic Rhizobia

[0164] A set of diverse native nif clusters were cloned in order to determine their relative performance in different strains and the associated species barriers (FIG. 1A). Previously-defined boundaries for the well-studied nif cluster from K. oxytoca (Arnold, W., Rump, A., Klipp, W., Priefer, U. B. & Paler, A. J. J. o. m. b. Nucleotide sequence of a 24,206-base-pair DNA fragment carrying the entire nitrogen fixation gene cluster of Klebsiella pneumoniae.

[0165] 203, 715-738 (1988)) and the small (10 kb) cluster from Paenibacillus polymyxa WLY7870 were used. Similarly, the published boundaries (43.7 kb) of the P. stutzeri A1501 (Yan, Y. et al. Nitrogen fixation island and rhizosphere competence traits in the genome of root-associated Pseudomonas stutzeri A1501. Proceedings of the National Academy of Sciences (2008)) and A. vinelandii DJ clusters were used (Hamilton, T. L. et al. Transcriptional profiling of nitrogen fixation in Azotobacter vinelandii. J Bacteriol 193, 4477-4486, doi:10.1128/JB.05099-11 (2011)). A region of the P. stutzeri A1501 nif cluster (Pst1307-Pst1312) was excluded as these genes are predicted to have no effect on nitrogenase. A. vinelandii DJ contains three putative electron transport systems (the Rnf1 and Rnf2 complexes and the Fix complex) located in other regions of the genome. RNA-seq data shows that Rnf2 is not co-expressed with the nif genes, so only the Rnf1 and Fix complexes were included by fusing their DNA to create a single 46.9 kb construct. The nif cluster

[0166] (40.1 kb) from Azospirillum brasilense Sp7 was selected because this species is a cereal endophyte and fixes nitrogen in free-living conditions. Several less-studied gene clusters were also cloned in order to probe species barriers. As a representative of cyanobacteria, the gene cluster from Cyanothece sp. ATCC51142 was cloned following published boundaries. Its transcriptional activator PatB occurs outside of the nif cluster, which was cloned along with its native promoter and fused to nif cluster to form a single construct (31.7 kb). Several gene clusters were selected from photosynthetic purple bacteria (Rhodopseudomonas palustris CGA009 (Oda, Y. et al. Functional genomic analysis of three nitrogenase isozymes in the photosynthetic bacterium Rhodopseudomonas palustris. 187, 7784-7794 (2005)) and Rhodobacter sphaeroides 2.4.1 (Haselkorn, R. & Kapatral, V. in Genomes and genomics of nitrogen-fixing organisms, 71-82 (Springer, 2005))) as these are members of the same alphaproteobacteria class as Rhizobia. The mf cluster, encoded on a separate chromosome of

[0167] R. sphaeroides 2.4.1, was added to the nif cluster to provide electrons to nitrogenase. Finally, the gene clusters from the sugarcane and rice endosymbiant Gluconacetobacter diazotrophicus PA1 5 (28.9 kb) as well as the three nif clusters from A. caulinodans ORS571 (64 kb).sup.37 were cloned together with an upstream regulator fixLJK, but these were found to be inactive in all species tested, so they are not shown in FIGS. 1A-1F. The precise genomic locations for all the nif clusters are provided in Table 2 and the plasmids containing nif clusters are provided in Table 3.

[0168] Each cluster was amplified from genomic DNA as multiple fragments by PCR and assembled with the plasmid backbone using yeast assembly (see Materials and Methods Section). The P. polymyxa WLY78 cluster was de novo synthesized based on the DNA sequence on contig ALJV01 (Shanks, R. M. et al. Saccharomyces cerevisiae-based molecular tool kit for manipulation of genes from gram-negative bacteria. 72, 5027-5036 (2006)). The clusters were cloned into different plasmid systems to facilitate transfer. For transfer to E. coli and R. sp. IRBG74, the broad-host range plasmid based on a pBBR1 origin was used (a second compatible RK2-origin plasmid was used for the nif cluster from A. caulinodans ORS571). These plasmids contain the RK2 oriT to enable the conjugative transfer of large DNA (see Materials and Methods). For transfer to P. protegens Pf-5, this plasmid system was found to be unstable and produce a mixed population. To transfer into this strain, the Pseudomonas-specific plasmid pRO1600 with the oriT was used. After construction, all of the plasmids were verified using next-generation sequencing (see Materials and Methods Section).

[0169] The set of 10 nif clusters were transferred into E. coli MG1655, the cereal epiphyte P. protegens Pf-5, and the cereal endophyte R. sp. IRBG74 to create 30 strains (FIG. 1A). E. coli was selected as a control as successful transfers to this recipient have been performed. Native P. protegens Pf-5 does not fix nitrogen. R. sp. IRBG74 contains two nif clusters in different genomic locations, which were left intact, but does not have nitrogenase activity under free living conditions. The genomic cluster does not have the required NifV enzyme as it obtains homocitrate from the plant. All of the clusters in the set have nifV, except the one from P. polymyxa WLY78. A test was run to determine whether the expression of recombinant WV from A. caulinodans ORS571 in R. sp. IRBG74 would result in active nitrogenase, but no activity was detected.

[0170] The bacteria were grown in appropriate media, including antibiotics, and then evaluated for nitrogenase activity using an acetylene reduction assay (see Methods and Materials Section). E. coli and Pseudomonas were grown at 30.degree. C. in BB minimal media, as described previously.sup.71. However, no growth was observed for R. sp. IRBG74 under these conditions. Different media and carbon sources were tested and it was found that UMS media with dicarboxylic acids (malate or succinate), the major carbon source from plants.sup.147, with 10 mM sucrose yielded the highest growth rates (FIG. 6). After overnight growth, cells were transferred to stoppered test tubes in ammonium-free minimal media to a final OD.sub.600 of 0.4. For E. coli, the headspace air is completely replaced with argon gas. For P. protegens Pf-5 and R. sp. IRBG74, the initial headspace concentration of oxygen was maintained at 1% because these bacteria require oxygen for their metabolism. The cells are incubated at 30.degree. for 20 hours in the presence of excess acetylene and the conversion to ethylene was quantified by GC-MS (see Materials and Methods Section). There was no significant growth for any of the strains under these conditions, so the nitrogenase activities reported correspond to the same cell densities.

[0171] A surprising 6 out of 10 clusters were functional in E. coli MG1655, with the K. oxytoca cluster producing the highest activity (FIG. 1A). The K. oxytoca cluster is also functional in P. protegens Pf-5, albeit with 60-fold less activity as compared to that in E. coli MG1655. Interestingly, the clusters from P. stutzeri and A. vinelandii--both obligate aerobes--are able to achieve high activities in P. protegens Pf-5. The resulting nitrogenase activities are 3- to 7-fold higher than that achieved from K. oxytoca, which only fixes nitrogen under strict anaerobic conditions. These clusters have common organizational features and similar electron transport chains, such as the Rnf complex.

[0172] A single gene cluster, from R. sphaeroides, yielded nitrogenase activity in R. sp. IRBG74 (FIG. 1A). Notably, both Rhizobium and Rhodobacter are alphaproteobacter and their nif clusters may contain interchangeable genes. When the native nif clusters are knocked out of R. sp. IRBG74, introducing the R. sphaeroides cluster alone does not yield active nitrogenase. These data point to a complex complementation between the endogenous and introduced gene clusters. To determine whether this approach could be generalized to other symbiotic Rhizobia, the Rhodobacter and Rhodopseudomonas gene clusters were transferred to a panel of 12 species isolated from diverse legumes (FIG. 1A). Remarkably, the transfer of these clusters was able to produce detectable nitrogenase activity in 7 of the strains.

[0173] Phylogenetic analysis was performed based on the full-length 16S rRNA gene sequences (K. oxytoca, BWI76_05380; A. vinelandii, Avin_55000; R. sphaeroides, DQL45_00005; Cyanothece ATCC51142, cce_RNA045; A. brasilense, AMK58_25190; R. palustris, RNA_55; P. protegens, PST_0759; Paenibacillus sp. WLY78, JQ003557). A multiple sequence alignment was generated using MUSCLE (Edgar, R. C. J. N. a. r. MUSCLE: multiple sequence alignment with high accuracy and high throughput. 32, 1792-1797 (2004)). A phylogenetic tree was constructed using the Geneious software (R9.0.5) with the Jukes-Cantor distance model and UPGMA as a tree build method, with bootstrap values from 1,000 replicates. This phylogenetic tree is shown in FIG. 30A. The scale bar indicates 2% substitutions per site. The clusters based on evolutionary closeness are circled. Using the same data from FIG. 1A, FIG. 30B summarizes the relative nitrogenase activity in the three host strains carrying each of the 10 nif clusters. The result indicates that the phylogenetic closeness has a predictive power for achieving highest nitrogenase activity in a new host that lacks a nif cluster.

[0174] Hereafter, studies were conducted to further characterize the extent to which changes in transcription and translation impacted the differences in activity observed when a native cluster is transferred between species. Differences in promoter activity, ribosome binding sites, and codon usage could change the expression levels of nif genes in detrimental ways. To quantify this effect, RNA-seq and ribosome profiling experiments were performed to evaluate the expression K. oxytoca nif cluster in K. oxytoca as well as E. coli MG1655, P. protegens Pf-5, and R. sp. IRBG74. RNA-seq experiments provide mRNA levels of genes (calculated as FPKM) and can be used to measure the performance of promoters and terminators. Ribosome profiling can be used to quantify protein synthesis rates, ribosome binding site (RBS) strength and ribosome pausing internal to genes. The ribosome density (RD) has been shown to correlate with protein expression rates. The translation efficiency is calculated by normalizing the RD by the number of transcripts (FPKM from Ribo-seq). Ribosome profiling has been applied to determine the relative levels of proteins expressed in multi-subunit complexes.

[0175] The RNA-seq profiles in both the sense and antisense direction are very close when compared between K. oxytoca and E. coli (FIGS. 1B-1C) and the ratios between mRNAs is preserved (R.sup.2=0.89) (FIG. 1D). This is consistent with the observation that this cluster yields a similar activity in both hosts. In contrast, the RNA-seq profiles differ more significantly for P. protegens Pf-5 and R. sp. IRBG74 (FIGS. 1B-1C), and there was no correlation between mRNA transcripts (FIG. 1D).

[0176] The ratios between protein expression rates were measured using ribosome profiling (FIG. 1E and FIG. 9). It is noteworthy that the ratios measured in K. oxytoca almost perfectly correlate with immunoblotting assays of A. vinelandii and the stoichiometry of H:D:K reflects the known 2:1:1 ratio. Interestingly, unlike mRNA levels, the ratios in expression rates are strongly correlated when the cluster is transferred between species: E. coli (R.sup.2=0.94), P. protegens Pf-5 (R.sup.2=0.61), and R. sp. IRBG74 (R.sup.2=0.71) (FIGS. 1E-1F). The production of NifH is significantly lower in R. sp. IRBG as compared to other strains. In an attempt to increase the induction of the cluster in this host, NifA was overexpressed, but this proved unsuccessful in producing high levels of active nitrogenase (FIGS. 10A-10B).

[0177] The following summarizes the results of the transfer of native nif clusters to new species. The most successful recipient was E. coli. However, this is not a viable agricultural strain and activity was eliminated in the presence of 17.1 mM ammonium (FIGS. 7A-7E, and FIGS. 8A-8B). Moderately high activity was obtained in P. protegens Pf-5, but this yielded a constitutively-on response (the K. oxytoca cluster) or was strongly repressed by ammonium (the A. vinelandii cluster). It was also found that the P. stutzeri cluster in P. protegens Pf-5 is inactive in the presence of ammonium, in disagreement with previously published results (Setten, L. et al. Engineering Pseudomonas protegens Pf-5 for nitrogen fixation and its application to improve plant growth under nitrogen-deficient conditions. PLoS One 8, e63666 (2013)). Only low levels of activity could be obtained by transferring clusters to Rhizobia. To address these issues, different approaches were applied to engineer the clusters to generate higher activity, exhibit less repression by ammonium, and be inducible.

Transfer of Refactored Klebsiella Nif Clusters to R. Sp. IRBG74

[0178] The process of refactoring a gene cluster involves the complete reconstruction of the genetic system from the bottom-up, using only well-characterized genetic parts. An exhaustive approach is to recode the genes (to eliminate internal regulation), reorganize into operons, control expression with synthetic ribosome binding sites (RBSs), and use T7 RNAP promoters and terminators. A separate "controller," carried in a genetically distinct location, links synthetic sensors and circuits to the expression of T7 RNAP. For various applications, this approach has proven useful for transferring multi-gene systems between species, simplifies optimization through part replacement and enzyme mining, and enables the replacement of environmental signals that naturally control the cluster with the stimuli that induce the synthetic sensors (Smanski, M. J. et al. Synthetic biology to access and expand nature's chemical diversity. Nature Reviews Microbiology 14, 135 (2016); Song, M. et al. Control of type III protein secretion using a minimal genetic system. 8, 14737 (2017); Guo, C.-J. et al. Discovery of reactive microbiota-derived metabolites that inhibit host proteases. 168, 517-526. e518 (2017); Ren, H., Hu, P., Zhao, H. J. B. & bioengineering. A plug-and-play pathway refactoring workflow for natural product research in Escherichia coli and Saccharomyces cerevisiae. 114, 1847-1854 (2017)). In previous studies, the Klebsiella nif cluster was refactored, which was subsequently used as a platform to optimize activity by changing the genetic organization and the parts controlling expression. The top variant (v2.1) fully recovered activity in a K. oxytoca nif knockout and is functional in E. coli. To transfer into E. coli, a controller based on the isopropyl-.beta.-D-thiogalactoside (IPTG)-inducible T7 RNAP carried on a plasmid was used (FIG. 2A). An interesting observation during optimization is that the genetic organization of the native cluster, including the existence of operons, was not correlated with activity.

[0179] An advantage of using T7 RNAP is that it is functional in essentially all prokaryotes, so the refactored cluster can be transferred as-is and transcription induced by expressing T7 RNAP in the new host. However, a new controller needs to be built for each host based on regulation and regulatory parts that work in that species. A controller for E. coli was designed based on the IPTG-inducible T7 RNAP carried on a plasmid (pKT249) (FIG. 2A). To transfer the refactored cluster to R. sp. IRBG74, first a controller was constructed that functions in this species and produces an equivalent range of T7 RNAP expression.

[0180] While a handful of inducible systems and sets of genetic parts have been previously described for Rhizobia, a new part collection needed to be built and characterized in order to have those needed to create a controller with sufficient dynamic range. First, a set of 20 constitutive promoters (Anderson, J. et al. BglBricks: A flexible standard for biological part assembly. 4, 1 (2010)) and seven T7 RNAP-dependent promoters (emme, K., Zhao, D. & Voigt, C. A. Refactoring the nitrogen fixation gene cluster from Klebsiella oxytoca. Proceedings of the National Academy of Sciences 109, 7085-7090 (2012)) that were found to span a range of 382-fold and 23-fold expression, respectively, were characterized (FIGS. 11A-11C). Second, a library of 285 ribosome binding sites (RBSs) were screened using the RBS Library Calculator, representing an expression range of 5,600-fold (FIGS. 12A-12B). Finally, a set of 29 terminators was characterized, of which 17 were found to have a terminator strength >10 (FIGS. 13A-13B). Using these part libraries, six inducible systems for R. sp. IRBG74 were then constructed that respond to IPTG, the quorum signal 3OC6HSL, aTc, cuminic acid, DAPG, and salicylic acid (FIG. 14). After optimization, these systems generate between 7- to 400-fold induction.

[0181] A controller was then constructed by using the optimized IPTG-inducible system to drive the expression of a variant of T7 RNAP (R6232S, N-terminal lon tag, GTG start codon) (FIG. 2A). RBS variants controlling T7 RNAP expression were tested and an intermediate strength was selected to maximize induction while limiting toxicity (FIG. 16). The controller was carried on the genome by replacing recA (see Materials and Methods). The response function of the final controller is compared to that obtained for pKT249 in E. coli, showing that they sweep through the same range of expression at intermediate levels of induction (FIG. 2B). To achieve the same level of induction in the two species, 0.1 mM IPTG is selected for E. coli and 0.5 mM for R. sp. IRBG74 (circled points in FIG. 2B).

[0182] The refactored v2.1 cluster was then transferred to R. sp. IRBG74, but no activity was observed (FIGS. 2C-2D). Activity was also not observed when the v2.1 cluster was transferred to P. protegens Pf-5 (FIG. 17). To determine if the genetic parts that make up the refactored cluster were functioning as designed, RNA-seq and ribosome profiling experiments were performed (FIG. 18). From these data, the strengths of promoters/terminators and the transcription level and translation rates of genes could be calculated (see Materials and Methods). The performance of the promoters in R. sp. IRBG74 was systematically lower than E. coli, particularly the first promoter controlling nifH (FIG. 2E). The terminators were functioning the same in the two species, albeit weakly, and no termination could be detected from the three terminators in the center of the cluster (FIG. 2E). The translation of the genes differed significantly between organisms (FIG. 2F). When the expression rates of the nif genes from the refactored cluster are compared with their levels in their native context in K. oxytoca, there is almost no correlation (FIG. 2F). Importantly, there is 9-fold less NifH expressed from the refactored cluster in R. sp. IRBG74 as compared to the same cluster in E. coli. Thus, the refactored cluster produces wildly different expression levels of the component genes when transferred between organisms, even when transcription is matched between them using different controllers.

[0183] Based on these results, a new refactored cluster (v3.2) (FIG. 2G) was designed. A very strong promoter was chosen for nifH. The transcription was broken up by adding promoters to divide nifENX and nifJ and selecting stronger terminators. Noting that the expression ratios between nif genes are better preserved when the native cluster is transferred to a new host (FIG. 1D) but not the refactored cluster (FIG. 2F), it was hypothesized that this could be due to the disruption of the operon structures and the associated translational coupling between genes. The K. oxytoca operons were cloned intact, including native RBSs and replaced these regions of the refactored cluster (FIG. 2G). Note that this also preserves nifT and nifX, which were not included in first versions because they were either inessential(Simon, H. M., Homer, M. J. & Roberts, G. P. J. J. o. b. Perturbation of nifT expression in Klebsiella pneumoniae has limited effect on nitrogen fixation. 178, 2975-2977 (1996)) or inhibitory (Gosink, M. M., Franklin, N. M. & Roberts, G. P. J. J. o. b. The product of the Klebsiella pneumoniae nifX gene is a negative regulator of the nitrogen fixation (nif) regulon. 172, 1441-1447 (1990)).

[0184] Compared to v2.1, the v3.2 cluster is less active in E. coli but is active in R. sp. IRBG74 (FIG. 2H) and P. protegens Pf-5 (FIG. 17). This experiment was performed in the double nif knockout strain in R. sp. IRBG74, thus indicating that the refactored cluster is self-contained in producing nitrogenase activity. RNA-seq and ribosome profiling was applied to evaluate the performance of v3.2 in all three species (FIG. 21, FIG. 19, and FIGS. 20A-20F). The promoters perform similarly in the different hosts, but there was significant diversity in terminator function. Despite this, the translation rates (RD) of the genes were remarkably consistent and NifH expression is nearly identical (FIG. 2J). The higher expression of NifH and the preserved ratios between proteins is the likely reason that the refactored cluster is functional in R. sp. IRBG74. The next attempt was to increase expression level of the nif genes in R. sp. IRBG74 by increasing the concentration of inducer used, but a clear optimum beyond which increased expression caused a rapid decline in activity was found (FIG. 2M). This indicates a potential upper limit in obtaining activity in R. sp. IRBG74 under free living conditions using only the genes from K. oxytoca.

Replacement of A. caulinodans Nif Regulation with Synthetic Control

[0185] The A. caulinodans nif genes are distributed across three clusters in different genomic locations. The regulatory signals converge on the NifA activator that, in concert with the RpoN sigma factor, turns on transcription of the genomic nif clusters. Numerous and not fully characterized environmental signals are integrated upstream of this node, including NtrBC (Kaminski, P. A. & Elmerich, C. J. M. m. The control of Azorhizobium caulinodans nifA expression by oxygen, ammonia and by the HF-I-like protein, NrfA. 28, 603-613 (1998)), NtrXY (Pawlowski, K., Klosse, U., De Bruijn, F. J. M. & MGG, G. G. Characterization of a novel Azorhizobium caulinodans ORS571 two-component regulatory system, NtrY/NtrX, involved in nitrogen fixation and metabolism. 231, 124-138 (1991)), FixLJK(Kaminski, P. & Elmerich, C. J. M. m. Involvement of fixLJ in the regulation of nitrogen fixation in Azorhizobium caulinodans. 5, 665-673 (1991); Kaminski, P., Mandon, K., Arigoni, F., Desnoues, N. & Elmerich, C. J. M. m. Regulation of nitrogen fixation in Azorhizobium caulinodans: identification of a fixK-like gene, a positive regulator of nifA. 5, 1983-1991 (1991)), NrfA (Kaminski, P. A. & Elmerich, C. J. M. m. The control of Azorhizobium caulinodans nifA expression by oxygen, ammonia and by the HF-I-like protein, NrfA. 28, 603-613 (1998)), and PII proteins (e.g., GlnB and GlnK (Michel-Reydellet, N. & Kaminski, P. A. J. J. o. b. Azorhizobium caulinodans Plland GlnK proteins control nitrogen fixation and ammonia assimilation. 181, 2655-2658 (1999))). The clusters (64 kb total, containing 76 genes) were cloned into the plasmid systems described above and transferred into R. sp. IRBG74 and P. protegens Pf-5, but no activity was found in either strain. Overexpression of A. caulinodans NifA and RpoN did not lead to activity and, upon further investigation, these regulators were found to be inactive in these strains. The size of the clusters and the lack of genetic and gene function information would complicate fully refactoring the system. For these reasons, it was decided to modify the regulation controlling nif such that it can be placed under the control of synthetic sensors.

[0186] One goal herein was to eliminate ammonium repression of nitrogenase activity, which converges on the regulation of NifA. The native nifA gene was knocked out of the genome using the sacB markerless deletion method (see Materials and Methods), with the intent of placing NifA under inducible control (FIG. 3A). There is only basal activity from the nifH promoter in the .DELTA.nifA strain (FIG. 3B). When NifA is overexpressed, the promoter turns on and its activity is further enhanced by the co-expression of RpoN in an operon (note that the genomic rpoN gene is left intact for these experiments). The IPTG-inducible system designed for Rhizobium (previous section) was tested in A. caulinodans carried on a pBBR1-ori plasmid. Using GFP, this was found to induce expression over several orders of magnitude (FIG. 21). Then, the A. caulinodans nifA and rpoN gene was placed under IPTG control and the fluorescent reporter fused to the A. caulinodans nifH promoter (encompassing 281 nt upstream of the ATG), carried on the same plasmid (see Materials and Methods). The response function from the nifH promoter was analyzed at the condition used for nitrogen fixation, exhibiting a wide dynamic range to 45-fold (FIG. 3C).

[0187] The controller was designed to co-express NifA and RpoN and tested for its ability to induce nitrogenase (FIG. 3D). When fully induced, there was a complete recovery of activity as compared to the wild-type strain. The repression of nitrogenase activity by ammonium was then evaluated. The presence of 10 mM ammonium chloride leads to no detectible activity by the wild-type strain (FIG. 3E). Even when both NifA and RpoN are under inducible control, there is strong repression with only 5% of the nitrogenase activity of the wild-type. This suggests that the post-transcriptional control of NifA activity by ammonium remains intact.

[0188] In related alphaproteobacteria, mutations have been identified in NifA that abrogate ammonium repression (Paschen, A., Drepper, T., Masepohl, B. & Klipp, W. Rhodobacter capsulatus nifA mutants mediating nif gene expression in the presence of ammonium. FEMS microbiology letters 200, 207-213 (2001); Rey, F. E., Heiniger, E. K. & Harwood, C. S. Redirection of metabolism for biological hydrogen production. Applied and environmental microbiology 73, 1665-1671 (2007)). These mutations occur in the N-terminal GAF domain. Using a multiple sequence alignment, two equivalent residues were identified to mutate in A. caulinodans (L94Q and D95Q) (FIG. 22). These mutations were made and then tested individually and in combination (FIG. 3D). When the double mutant of NifA is co-expressed with RpoN, the presence of ammonium only results in a slight decrease in activity.

[0189] Oxygen irreversibly inhibits nitrogenase and represses nif clusters. The inducible nif clusters were tested for oxygen sensitivity, noting that A. caulinodans is an obligate aerobe and fixes nitrogen under micro-aerobic conditions. The tolerance of nitrogenase to oxygen was then assessed as a function of the concentration of oxygen in the headspace, held constant by injecting oxygen while monitoring its level (Methods and FIG. 26A). The native and inducible gene clusters responded nearly identically to oxygen (FIG. 3F). The optimum activity occurs between 0.5% to 1% with a wide tolerance (30% activity at 3% oxygen).

Introduction of Controllable Nif Activity in P. protegens Pf-5

[0190] The native K. oxytoca, P. stutzeri, and A. vinelandii nif clusters are all functional in P. protegens Pf-5 (FIG. 1A). However, when the native P. stutzeri and A. vinelandii clusters are transferred, nitrogenase is strongly repressed. In contrast, transferring the native K. oxytoca cluster produces uncontrolled (constitutively on) nitrogenase activity (FIG. 4E). For these three clusters in P. protegens Pf-5, it was sought to gain regulatory control by removing the nifA master regulators from the clusters and expressing them from a controller (FIG. 4A).

[0191] As with Rhizobia, it was found that first, part libraries for P. protegens Pf-5 had to be built before building controllers with sufficient dynamic range. A range of 20 constitutive promoters and seven T7 promoters that span a range of 778-fold and 24-fold expression, respectively, was characterized (FIGS. 11A-11C). A library of 192 RBSs was screened, representing an expression range of 4,079-fold (FIGS. 12A-12B). A set of seven terminators that share no sequence homology between each other and have a terminator strength >10 in R. sp. IRBG74 was selected and characterized together with the three well-used terminators (e.g., T7 terminator, rrnBT1, and L3S2P21). These seven terminators showed a terminator strength >50 (FIGS. 13A-13B).

[0192] The inducible systems designed for Rhizobium were transferred as-is to a Pseudomas-specific pRO1600 plasmid (see Materials and Methods). The 3OC6HSL-, aTc-, cuminic acid-, and DAPG-inducible systems were all found to be functional (FIG. 15A). In addition, a naringenin-inducible system based on the P.sub.fde promoter was constructed and found to be functional. The strength of arabinose inducible system was increased by substituting the -10 box in P.sub.BAD promoter and arabinose import was improved by constitutive expression of the arabinose transporter AraE (FIG. 15B). Finally, the IPTG-inducible system was optimized for P. protegens Pf-5 by replacing the P.sub.A1lacO1 promoter with the P.sub.tac promoter and making three amino acid substitutions to Lad (Meyer, A. J., Segall-Shapiro, T. H., Glassey, E., Zhang, J. & Voigt, C. A. J. N. c. b. Escherichia coli "Marionette" strains with 12 highly optimized small-molecule sensors. 1 (2018)). This effort resulted in seven new inducible systems that produce 41- to 554-fold induction in P. protegens Pf-5 (FIG. 15C).

[0193] To simplify the comparison between clusters, it was sought to build a single, universal controller that could induce all three. Each has a different NifA sequence, so the ability to cross induce the gene clusters was tested. To do this, the nifH promoters from each nif cluster were cloned and fused to gfp to build plasmid-based reporters (see Materials and Methods). The ability of the various NifA homologues to activate the nifH promoters was evaluated in E. coli and P. protegens Pf-5 (FIG. 23A-23B). The results suggest that it is more important to express a NifA variant from a similar species as the host, as opposed to expressing the NifA variant that is cognate to the transferred cluster. This may be due to the need for NifA to recruit host transcriptional machinery, whereas the NifA binding sites in the promoters are well conserved across species. Based on these data, the controller was constructed using the P. stutzeri NifA, placed under the control of the optimized IPTG-inducible system, described above. The RBSs of NifA were synthetically designed to span a wide range of expression of nif genes (FIG. 24A). The controller was inserted into the genome 25 bp downstream of the stop codon of glmS using the mini-Tn7 system. The ability for this controller to induce the nifH promoter from each cluster using a fluorescent reporter is shown in FIG. 4C and FIG. 24B.

[0194] The nitrogenase activity for each of the gene clusters in P. protegens Pf-5 was then assessed (FIG. 4D). The three P. protegens Pf-5 strains containing the transferred clusters were modified to insert the controller and delete the native nifLA genes from each cluster (FIG. 4B). All three are inducible, with nitrogenase activity showing dynamic ranges of 1,200-fold, 2,300-fold, and 130-fold for the K. oxytoca, P. stutzeri, and A. vinelandii nif clusters, respectively. When induced, these systems all produce similar or even higher nitrogenase activities than can be achieved by the transfer of the unmodified native clusters (FIG. 4D). For reference, the nitrogenase activities produced by K. oxytoca, P. stutzeri, and A. vinelandii are shown as dashed lines in FIG. 4D (top to bottom) (see Methods and Materials). All three inducible clusters produce similar levels of activity that approach those measured from wild-type P. stutzeri and A. vinelandii.

[0195] The native P. stutzeri and A. vinelandii clusters are strongly repressed by ammonium: the presence of 17.1 mM eliminates activity or reduces it 7-fold, respectively (FIG. 4E and FIGS. 8A-8B). The inducible clusters show little reduction in activity and the inducible A. vinelandii cluster exhibits almost no ammonia repression. While the native K. oxytoca cluster in P. protegens Pf-5 generates a constitutive response, there is still some repression, which is reduced by the inducible version.

[0196] The inducible nif clusters were tested for oxygen sensitivity. Note that wild-type A. vinelandii is able to fix nitrogen under ambient conditions due to genetic factors internal and external to the cluster. First, it was established that the controller in P. protegens Pf-5 could induce transcription from the three nifH promoters in the presence of oxygen (FIGS. 26A-26B). The tolerance of nitrogenase to oxygen was then assessed as a function of the concentration of oxygen in the headspace, as described for A. caulinodans (previous section). The native and inducible clusters exhibited the same oxygen response (FIG. 4F). The nif cluster from K. oxytoca was the most sensitive, generating the highest activity under anaerobic conditions, but this is quickly abolished in the presence of 02. In contrast, the nif clusters from P. stutzeri and A. vinelandii showed wider tolerance with optima at 1% and 0.5%, respectively. However, both clusters lose activity at lower oxygen concentrations than A. caulinodans.

[0197] To explore the impact of the electron transport chains, several mutants to the A. vinelandii cluster were made (FIG. 27). The A. vinelandii cluster contains two potential electron transport systems to nitrogenase and the redundant system may help maintain redox status for nitrogenase at various oxygen levels. The dependence of nitrogenase activity on the oxygen concentration in various mutant backgrounds was re-measured. No effect was seen by adding the rnf2 operon or deleting the fix operon, however deleting rnf1 eliminated activity. This suggests that the rnf1 operon is the sole source of electrons in P. protegens Pf-5 under these conditions and the Fix complex cannot compensate the Rnf complex unlike the case of A. vinelandii.

Control of Nitrogen Fixation with Agriculturally-Relevant Sensors

[0198] The careful design and characterization of the controller has the benefit of simplifying the process by which different synthetic sensors can be used to induce nitrogenase expression. By knowing the dynamic range required to go from inactive to active nitrogenase, one can quantitatively select sensors that have the produce a compatible response. This allows different environmental signals--or combinations of signals using genetic logic circuits--to be used to control expression. To demonstrate this, 11 synthetic sensors were selected that respond to a variety of chemical signals of relevance to the rhizosphere and demonstrate that these can be used to create inducible nitrogenase in for example, engineered strains of E. coli (carrying the refactored v2.1 nif), R. sp. IRBG74 (carrying the refactored v3.2 nif), P. protegens Pf-5 (carrying the inducible A. vinelandii nif), and A. caulinodans (inducible nifA/rpoN) (FIGS. 5A-5D).

[0199] The roles of the chemical signals in the rhizosphere are shown in FIG. 5A. Cuminic acid is present in plant seeds and functions as a fungicide. Natural root exudates may include sugars, amino acids, organic acids, phenolic compounds, phytohormones, and flavonoids. These represent potential signals to control nitrogenase production close to the root surface. Cereals have been shown to release arabinose, vanillic acid, and salicylic acid. In addition, salicylic acid regulates the plant innate immune response and the impact of its exogenous addition to cereals has been studied. Naringenin is a common precursor for many flavonoids and improves endophytic root colonization when applied to rice and wheat. Genistein, a product from naringenin catalyzed by the isoflavone synthase, is released from maize roots. A quorum sensing mimic released by rice can regulate the 3OC6HSL receptor protein LuxR, which has been visualized using E. coli biosensor strains.

[0200] Bacteria either native to the rhizome or added as biocontrol agents introduced as a spray inoculant or seed coating produce chemical signatures. Inoculation of cereals with root colonizing Pseudomonas strains that produce DAPG elicits protection against fungal pathogens. Many bacteria produce quorum molecules, such as N-acyl homoserine lactones, as a means of communication and plants can respond to these signals. The bacterium Sinorhizobium meliloti produces 3OC14HSL, which enhances Medicago nodulation and has been shown to induce systemic resistance in cereals. DHBA can be produced by root colonizing bacteria to increase iron solubility and play a role as a chemoattractant for Agrobacterium and Rhizobium.

[0201] Sensors for these chemicals were constructed based on the controllers for each species. For E. coli MG1655, a strain that contains 12 optimized sensors, carried in the genome, that respond to various small molecules ("Marionette") had been previously constructed (Meyer, A. J., Segall-Shapiro, T. H., Glassey, E., Zhang, J. & Voigt, C. A. J. N. b. Escherichia coli "Marionette" strains with 12 highly optimized small-molecule sensors. 1 (2018).). The response functions of these sensors were characterized in standard units, making it simple to identify those that can be connected to nitrogenase expression without further tuning. Marionette contains sensors for vanillic acid, DHBA, cuminic acid, 3OC6HSL, and 3OC14HSL. For each sensor, the output promoter was transcriptionally fused to T7 RNAP and the response of the responsive promoter (PT7) was measured as a function of inducer concentration (FIG. 5B and FIG. 28B). Then, the v2.1 refactored nif cluster was introduced and nitrogenase activity was measured in the presence and absence of inducer (FIG. 5C and FIG. 28C). The inducible systems constructed for P. protegens Pf-5 that respond to arabinose and naringenin were used to drive NifA expression for the control of the A. vinelandii nif cluster (FIG. 4A). The induction of the nifH promoter by these sensors was first confirmed using a reporter (FIG. 5B). When this is replaced with the nif gene cluster, it results in an inducible response of nitrogenase activity (FIG. 5C). The best nitrogenase activity in R. sp. IRBG74 is low; however, herein it was demonstrated that it could be placed under inducible control. The DAPG-inducible system developed for R. sp. IRBG74 was connected to the control of T7 RNAP and this produces a strong response from PT7 (FIG. 5B). However, when used to drive the expression of the v3.2 refactored pathway, only a 9-fold induction is observed, consistent with the low nitrogenase activity observed in this strain (FIG. 5C). Finally, the salicylic acid sensor designed for Rhizobium was used to control NifA (L94Q/D95Q)/RpoN expression in A. caulinodans (FIG. 3A and FIG. 5B). This yielded a 1000-fold dynamic range of nitrogenase activity (FIG. 5C).

[0202] Plants could be engineered to release an orthogonal chemical signal that could then be sensed by a corresponding engineered bacterium. This would have the benefit of only inducing nitrogenase in the presence of the engineered crop. Further, if the molecule is metabolizable by the engineered bacterium, it could serve as a mechanism around which a synthetic symbiosis could be designed, where the plant provides the carbon and the bacterium fixed nitrogen in an engineered relationship. To this end, legumes and Arabidopsis have been engineered to produce opines, including nopaline and octopine. Sensors were constructed for these two opines for A. caulinodans based on the LysR-type transcriptional activators OccR (octopine) and NocR (nopaline) and their corresponding P.sub.occ and P.sub.noc promoters (FIG. 5D and FIG. 21). These sensors were connected to the expression of NifA(L94Q/D95Q)/RpoN and the response from P.sub.nifH was measured using a fluorescent reporter. Both response functions had a large dynamic range (FIG. 5B) and produced highly-inducible nitrogenase activity (FIG. 5C). The nopaline sensor yielded a 412-fold dynamic range and the octopine sensor led to 40% higher nitrogenase activity than the wild-type.

Discussion

[0203] Towards designing a bacterium that can deliver fixed nitrogen to a cereal crop, this work provides a side-by-side comparison of diverse species, natural nif clusters, and engineering strategies that can be used to obtain inducible nitrogenase activity in a strain that can associate with cereals as an endophyte or epiphyte. To this end, .about.100 strains involving the transfer of 10 natural nif clusters ranging in size from 10 kb to 64 kb to 16 diverse species of Rhizobia, Azorhizobium, Pseudomas, and E. coli were constructed. Different approaches were taken to make these nif clusters inducible, from bioinformatics and protein engineering to complete genetic reconstruction from the ground-up (refactoring). In addition to the highest activity, it is important that nitrogen fixation be robust to the addition of nitrogenous fertilizer (ammonia) and microaerobic environments. For example, an endophyte such as a variant of Azorhizobium where nifA is knocked out of the genome and a nifA mutant and rpoN are complemented on a plasmid can be used to obtain high nitrogenase activities. For an epiphyte, P. protegens Pf-5, is a versatile strain based on the transfer of the A. vinelandii nif cluster and placement of nifA of P. stutzeri under inducible control. In both such cases, nitrogenase activities were obtained that are nearly identical to wild-type A. caulinodans and P. stutzeri, respectively. Neither showed significant repression by ammonia and optimal activity was obtained in 1% oxygen. Based on these strains, it was demonstrated that nitrogenase can be placed under inducible control in response to cereal root exudates (arabinose, salicylic acid), phytohormones (naringenin) and putitive signaling molecules that could be released by genetically modified plants (e.g., can express or exudate nopaline or octopine).

[0204] Because R. sp. IRBG74 can fix nitrogen in a legume nodule and also associates with rice, significant effort was directed to engineering this strain to fix nitrogen when cereal-associated. The first attempt was simply complementing nifV, as this is absent in R. sp. IRBG74 and produces a metabolite provided by the plant, but this attempt was unsuccessful. Then, it was found that all of the initial nif clusters transferred, some of which have high activity in P. protegens Pf-5 and E. coli, are non-functional in R. sp. IRBG74, which led to trying clusters from alphaproteobacteria, one of which produced a very low level of activity that was dependent on the nif genes native to R. sp. IRBG74. The previously-published refactored gene clusters based on Klebsiella nif were attempted in R. sp. IRBG74 but these showed no activity. It was only after the construction of a new refactored cluster (v3.2) that activity was obtained under free-living conditions that was not dependent on the native nif genes. This allowed an increase in the expression levels, and an optimum was discovered beyond which activity was lost. This is the first time that nif activity has been engineered in a Rhizobium under free-living conditions that could otherwise not perform this function.

[0205] The present disclosure encompasses different degrees of nif pathway re-engineering to promote heterologous transfer. The most ambitious is the complete refactoring of all the nif genes and regulation, where all regulatory genetic parts are replaced, genes are recoded, operons are reorganized, and transcription is performed by the orthogonal T7 RNAP. Initially, the evaluation of performance relied on the overall nitrogenase activity, rather than an understanding of the underlying parts. As such, the first refactored pathway performed poorly. In subsequent studies, better part libraries and DNA assembly and automation platforms enabled the synthesis of many variants. Further, as the cost of RNA-seq declined, it was used to evaluate the performance of internal parts, such as promoters and terminators. This revealed that the first designs were effectively large single operons with little differential control over the transcription levels of individual genes. With these techniques allowed the tailoring of the function of the refactored nif pathway and the discovery that many of the underlying genetic structure were not needed to achieve high activities.

[0206] Ribosome profiling, a new technique that enables the measurement of translational parts (e.g., ribosome binding sites), was applied and expression levels were inferred. Further, nitrogenase activity and the function of underlying parts were assessed as the clusters were moved between species. Interestingly, the native Klebsiella nif cluster could be transferred and it performed similarly but the refactored cluster yielded widely varying expression levels in the different hosts, sometimes leading to a total loss in activity. This could be recovered by maintaining the native operon structure in the refactored cluster, implying that it was not due to the synthetic sensors, T7 RNAP, or promoters/terminators. This is one of the hypothesized functions of operons. Achieving this required maintenance of the codon usage and translational coupling of the native cluster. However, this does not mean that it will not be possible to also encode this function synthetically. There have been computational advances that enable the calculation of RBSs internal to upstream genes when encoded on an operon. If coupled with codon optimization algorithms, this would allow the design of de novo genetic parts that achieve a desired degree of translational coupling and expression level.

[0207] The present disclosure demonstrates the deregulation of nif clusters in A. caulinodans and P. protegens Pf-5, enabling them to be placed under the control of cereal root exudates. This derepresses the pathway in the presence of exogenous nitrogenous fertilizer--critical for the use of the bacterium as part of an integrated agricultural solution. Further, these organisms retain the ability to fix nitrogen in microaerobic environments, thus avoiding the need for a root nodule that enforces strict anaerobiosis. The complete deregulation of the nif pathway makes the bacterium non-competitive in the soil and lost quickly, thus limiting its impact to particular phases of the growth cycle. Thus, it is demonstrated that nitrogenase can be placed under the control of chemical root exudates.

EMBODIMENTS

[0208] 1. A rhizobium that can fix nitrogen under aerobic free-living conditions, comprising a symbiotic rhizobium having an exogenous nif cluster, wherein the exogenous nif cluster confers nitrogen fixation capability on the symbiotic rhizobium under aerobic free-living conditions, and wherein the rhizobium is not Azorhizobium caulinodans.

[0209] 2. The rhizobium of paragraph 1, wherein the exogenous nif cluster is from a free-living diazotroph.

[0210] 3. The rhizobium of paragraph 1, wherein the exogenous nif cluster is from a symbiotic diazotroph.

[0211] 4. The rhizobium of paragraph 1, wherein the exogenous nif cluster is from a photosynthetic Alphaproteobacteria.

[0212] 5. The rhizobium of paragraph 1, wherein the exogenous nif cluster is from a Gammaproteobacteria.

[0213] 6. The rhizobium of paragraph 1, wherein the exogenous nif cluster is from a cyanobacteria.

[0214] 7. The rhizobium of paragraph 1, wherein the exogenous nif cluster is from a firmicutes.

[0215] 8. The rhizobium of paragraph 1, wherein the exogenous nif cluster is from Rhodobacter sphaeroides.

[0216] 9. The rhizobium of paragraph 1, wherein the exogenous nif cluster is from Rhodopseudomonas palustris.

[0217] 10. The rhizobium of paragraph 1, wherein the exogenous nif cluster is an inducible refactored nif cluster.

[0218] 11. The rhizobium of paragraph 10, wherein the inducible refactored nif cluster is an inducible refactored Klebsiella nif cluster.

[0219] 12 The rhizobium of any one of the preceding paragraphs, wherein the rhizobium is IRBG74.

[0220] 13. The rhizobium of any one of the preceding paragraphs, wherein the exogenous nif cluster comprises 6 nif genes.

[0221] 14. The rhizobium of paragraph 13, wherein the 6 nif genes are nifHDK(T)Y, nifEN(X), nifJ, nifBQ, nifF, and nifUSVWZM.

[0222] 15. The rhizobium of paragraphs 13 or 14, wherein each nif gene of the exogenous nif cluster is preceded by a T7 promoter.

[0223] 16. The rhizobium of paragraph 15, wherein the T7 promoter is a wild-type promoter.

[0224] 17. The rhizobium of any one of the preceding paragraphs, further comprising an endogenous nif cluster.

[0225] 18. The rhizobium of any one of the preceding paragraphs, wherein the nif cluster has a nifV gene.

[0226] 19. The rhizobium of paragraph 18, wherein the nifV gene is endogenous.

[0227] 20. The rhizobium of any one of the preceding paragraphs, wherein the exogenous nif cluster further comprises a terminator.

[0228] 21. The rhizobium of any one of paragraphs 15-20, wherein the T7 promoter has a terminator and wherein the terminator is downstream from the T7 promoter.

[0229] 22. The rhizobium of paragraph 12, wherein the exogenous nif cluster is a refactored rhizobium IRBG74 nif cluster.

[0230] 23. A plant growth promoting bacterium that can fix nitrogen under aerobic free-living conditions, comprising a bacterium having an exogenous nif cluster having at least one inducible promoter, wherein the exogenous nif cluster confers nitrogen fixation capability on the bacterium, under aerobic free-living conditions, and wherein the bacterium is not Azorhizobium caulinodans.

[0231] 24. The plant growth promoting bacterium of paragraph 23, wherein the bacterium is a symbiotic bacterium.

[0232] 25. The plant growth promoting bacterium of paragraph 23, wherein the bacterium is an endophyte.

[0233] 26. The plant growth promoting bacterium of paragraph 25, wherein the endophyte is rhizobium IRBG74.

[0234] 27. The plant growth promoting bacterium of paragraph 23, wherein the bacterium is an epiphyte.

[0235] 28. The plant growth promoting bacterium of paragraph 27, wherein the epiphyte is pseudomonas protogens PF-5.

[0236] 29. The plant growth promoting bacterium of any one of paragraphs 23-28, wherein the plant growth promoting bacterium is associated with a genetically modified cereal plant.

[0237] 30. The plant growth promoting bacterium of paragraph 29, wherein the genetically modified cereal plant includes an exogenous gene encoding a chemical signal.

[0238] 31. The plant growth promoting bacterium of paragraph 29, wherein the nitrogen fixation is under the control of the chemical signal.

[0239] 32. The plant growth promoting bacterium of paragraphs 30 or 31, wherein the chemical signal is opine, phlorogluconol or rhizopene.

[0240] 33. The rhizobium of any one of paragraphs 23-32, wherein the exogenous nif cluster comprises 6 nif genes.

[0241] 34. The rhizobium of paragraph 33, wherein the 6 nif genes are nifHDK(T)Y, nifEN(X), nifJ, nifBQ, nifF, and nifUSVWZM.

[0242] 35. The rhizobium of any one of paragraphs 23-34, wherein the inducible promoter is a T7 promoter.

[0243] 36. The rhizobium of any one of paragraphs 23-34, wherein the inducible promoter is P.sub.A1lacO1 promoter.

[0244] 37. The rhizobium of any one of paragraphs 23-36, wherein the inducible promoter is activated by an agent selected from a group that includes IPTG, sodium salicylate, octapine, nopaline, the quorum signal 3OC6HSL, aTc, cuminic acid, DAPG, and salicylic acid.

[0245] 38. The rhizobium of any one of paragraphs 23-37, wherein the exogenous nif cluster further comprises a terminator.

[0246] 39. The rhizobium of any one of paragraphs 23-37, wherein the inducible promoter has a terminator and wherein the terminator is downstream from the inducible promoter.

[0247] 40. An Azorhizobium caulinodans capable of inducible ammonium-independent nitrogen fixation in a cereal crop, comprising:

[0248] (i) a modified nif cluster, wherein an endogenous nifA gene is deleted or altered; and

[0249] (ii) at least one operon comprising nifA and RNA polymerase sigma factor (RpoN), wherein the operon comprises a regulatory element including an inducible promoter.

[0250] 41. The Azorhizobium caulinodans of claim 40, wherein the inducible promoter is P.sub.A1lacO1 promotor.

[0251] 42. The Azorhizobium caulinodans of paragraphs 40 or 41, wherein the inducible promoter is activated by an agent selected from IPTG, sodium salicylate, octapine, nopaline, the quorum signal 3OC6HSL, aTc, cuminic acid, DAPG, and salicylic acid.

[0252] 43. The Azorhizobium caulinodans of any one of paragraphs 40-42, wherein the endogenous nifA gene is altered with at least one of the following substitutions:

[0253] (i) L94Q;

[0254] (ii) D95Q; and

[0255] (iii) both L94Q and D95Q.

[0256] 44. A method of engineering a rhizobium that can fix nitrogen under aerobic free-living conditions, comprising transferring an exogenous nif cluster to a symbiotic rhizobium, wherein the exogenous nif cluster confers nitrogen fixation capability on the symbiotic rhizobium, under aerobic free-living conditions, and wherein the rhizobium is not Azorhizobium caulinodans.

[0257] 45. The method of paragraph 44, wherein the exogenous nif cluster comprises 6 nif genes.

[0258] 46. The method of paragraph 45, wherein the 6 nif genes are nifHDK(T)Y, nifEN(X), nifJ, nifBQ, nijF and nifUSVWZM.

[0259] 47. The method of paragraph 45 or 46, wherein each of the nif genes is preceded by a wild-type T7 promoter.

[0260] 48. The method of any one of paragraphs 44-47, wherein the exogenous nif cluster is transferred to the rhizobium in a plasmid.

[0261] 49. The method of any one of paragraphs 44-48, wherein the exogenous nif cluster further comprises a terminator.

[0262] 50. The method of any one of paragraphs 47-49, wherein the wild-type T7 promoter has a terminator, and wherein the terminator is downstream from the wild-type T7 promoter.

[0263] 51. The method of any one of paragraphs 44-50, wherein the endogenous NifL gene is deleted.

[0264] 52. A method of producing nitrogen for consumption by a cereal plant, comprising providing a plant growth promoting bacterium that can fix nitrogen under aerobic free-living conditions in proximity of the cereal plant, wherein the plant growth promoting bacterium is a symbiotic bacterium having an exogenous nif cluster, wherein the exogenous nif cluster confers nitrogen fixation capability on the symbiotic bacterium, enabling nitrogen fixation under aerobic free-living conditions.

[0265] 53. The method of paragraph 52, wherein the plant growth promoting bacterium is a rhizobium.

[0266] 54. The method of paragraph 52, wherein the plant growth bacterium is the bacterium of any one of paragraphs 1-22 and 23-39.

[0267] 55. The method of any one of paragraphs 52-54, wherein the cereal plant is a genetically modified cereal plant.

[0268] 56. The method of paragraph 55, wherein the genetically modified cereal plant includes an exogenous gene encoding a chemical signal.

[0269] 57. The method of paragraph 56, wherein the nitrogen fixation is under the control of the chemical signal.

[0270] 58. The method of paragraph 56 or 57, wherein the chemical signal is opine, phlorogluconol or rhizopene.

[0271] 59. The method of any one of paragraphs 52-55, wherein the nitrogen fixation is under the control of a chemical signal.

[0272] 60. The method of paragraph 57 or 59, wherein the chemical signal is a root exudate, biocontrol agent or phytohormone.

[0273] 61. The method of paragraph 60, wherein the root exudate is selected from the group consisting of sugars, hormones, flavonoids, and antimicrobials.

[0274] 62. The method of paragraph 57 or 59, wherein the chemical signal is vanillate.

[0275] 63. The method of paragraph 57 or 59, wherein the chemical signal is IPTG, aTc, cuminic acid, DAPG, and salicylic acid, 3,4-dihydroxybenzoic acid, 3OC6HSL or 3OC14HSL.

[0276] All of the features disclosed in this specification may be combined in any combination. Each feature disclosed in this specification may be replaced by an alternative feature serving the same, equivalent, or similar purpose. Thus, unless expressly stated otherwise, each feature disclosed is only an example of a generic series of equivalent or similar features. From the above description, one skilled in the art can easily ascertain the essential characteristics of the present invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions. Thus, other embodiments are also within the claims.

EQUIVALENTS

[0277] While several inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the inventive teachings is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.

[0278] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.

[0279] All references, patents and patent applications disclosed herein are incorporated by reference with respect to the subject matter for which each is cited, which in some cases may encompass the entirety of the document.

[0280] The indefinite articles "a" and "an," as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean "at least one."

[0281] The phrase "and/or," as used herein in the specification and in the claims, should be understood to mean "either or both" of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with "and/or" should be construed in the same fashion, i.e., "one or more" of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the "and/or" clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to "A and/or B", when used in conjunction with open-ended language such as "comprising" can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0282] As used herein in the specification and in the claims, "or" should be understood to have the same meaning as "and/or" as defined above. For example, when separating items in a list, "or" or "and/or" shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as "only one of" or "exactly one of," or, when used in the claims, "consisting of," will refer to the inclusion of exactly one element of a number or list of elements. In general, the term "or" as used herein shall only be interpreted as indicating exclusive alternatives (i.e. "one or the other but not both") when preceded by terms of exclusivity, such as "either," "one of," "only one of," or "exactly one of." "Consisting essentially of," when used in the claims, shall have its ordinary meaning as used in the field of patent law.

[0283] As used herein in the specification and in the claims, the phrase "at least one," in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase "at least one" refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B," or, equivalently "at least one of A and/or B") can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

[0284] It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited.

ADDITIONAL TABLES

TABLE-US-00002 [0285] TABLE 2 Primers used for nif cluster cloning. Nif cluster Forward primer (SEQ ID NOs: 8-64) Reverse Primer (SEQ ID NOs: 65-121) Genomic location GenBank accession No. Klebsiella oxytoca CGTAGGGCGCATTAATGCAGCTGGCACGA GTGACGCTCGCGTATCAGGTTTG 3,897,443-3,909,294 CP020657.1 M5aI CAGGTGAATTC TAGACTGCTGGATACGCTGCTTAAGGTC TACGCTGTTTGAGCTGGCAAACCT ATCAGGCGCATATTTGAATGTATTTACTGCA 3,909,255-3,920,878 CP020657.1 GCGGCCGCTTCTAG AGTGACCAAAAGCTTCCGCAACCC Pseudomonas GCCCGGAGAGCAAGCCCGTAGGGCGCATT ACTACGCATCACTAGCAGGGCACGCACCGCG 1,410,207-1,414,229 NC_009434 stutzeri AATGCAGCTGG GACGAAATCGAAGT A1501 CACGACAGGTGTTAGGTTGGCCTGAATTC GAG GGTGT GGCTCACTTCGATTTCGTCCGCGGTGCGT TTGTCGACTCCCGGGGTCTGAC 1,419,757-1,424,637 NC_009434 GCCCTGCTAGT GATGCGTA CGCCTGATTTCGCCTGATGAACAGG GGCTTTAACGGCATGTTCCGGGT 1,424,588-1,429,971 NC_009434 TGACGCTGTTGACCACCGCC GTAGTCGTCGTTGTGGCCGAACTC 1,429,922-1,434,417 NC_009434 ATGGAAGTGGTCGGCACCGGCTA AAAGCATCATCTCGGGTCGGGC 1,434,370-1,438,503 NC_009434 CGCAACGGTTGGGGTAGGTTGG CGTCGAGCGACAACGCCTCGA 1,438,454-1,442,613 NC_009434 GACGTCCATCGCTTCGGCTTCGA CTATGAGCTGGACTGAACCGCGATG 1,442,565-1,448,340 NC_009434 CTGCGAAATCGACGCTGTCGAGCATCATC GAAAATACCGCATCAGGCGCATATTTGAATG 1,448,291-1,459,252 NC_009434 GCGGTTCA TATTTACTGCAGCG GCCGCTGGCGAATCTCCTTCCTCGGTTCG Azotobacter ATCCATTCTCAGGCTGTCTCGTCTCGTCT GCCTTCGAACATGTTGTCCCAG 134,732-144,115 NC_012560 vinelandii CTACGTACGCG DJ GATCCCAGGCAACGTCTTCGTACTGCGGT ACCGGGTTGCG GGGGCAGCCAGTGGAAAAAGG CTACGGCACGCCCTGGTTCGA TCGAGTTCGAGCAGTTTCTCCAGC 144.076-148,534 NC_012560 GCTCGGAAAGTGCTGGAGAAAC AGCGAACAATACCTGTGGCC 148,500-152,895 NC_012560 AAATCAGACATTCATGGCCACAGG TGGCGCTTGCCCTTGTTCCAA 152,861-157,152 NC_012560 TCTACCATGGCGTGACTCTCGG GCGCGGTGGTAGAGTTCCGGGAGTTTAAACG 157,101-162,181 NC_012560 GACAGAAGACGAGT CGTGCGGGC ACTCGTCTTCTGTCCGTTTAAACTCCCGG TTGCTCAGGGTCGGGTTGGC 5,161,399-5,168,611 NC_012560 AACTCTACCAC CGC CTTGGATAGACGAGGCACAGC CATCATCCTCGGCCCCTTCAGGTTGCAGGAG 5,168,561-5,175,635 NC_012560 CCGGCTTG GCCGGCTCCTGCAACCTGAAGGGGCCGAG GCAAGCCACTCCACTGACGAA 995,860-1,000,698 NC_012560 GATGATG Paenibacillus GAATTGAGGATAAATGTCAGGGATTTCAT ACAGGTTCCGCAGTTCACAAGC 23,686-26,413 ALJV01.1 polymyxa G contig00089 WLY78 CCAAGCATTTTGAGATCGCGGATG GCTGATTGTGATCGACAATATTCGG 26,364-27,763 ALJV01.1 contig00089 CGGAGGTGCCGGTATGAGCGA GAAAGCCTACACGAAGCAAAGG 27,714-29,113 ALJV01.1 contig00089 GAAGTTTGCAGCGAAAGAGGCG CTTGAGAATCTGCCGGGCGCCT 29.064-30,463 ALJV01.1 contig00089 GGGATGATGCAGAATACATCCCG ATCCACAAATCAACACCCTGCG 30,414-31,813 ALJV01.1 contig00089 GGTGACCTGGATGATGCAGAGGAGAG AAAGCGTTCCAGTCACGGTCAC 31,764-34,402 ALJV01.1 contig00089 Cyanothece GGCCCGCGTTAGGTTGGCCTGAATTCGGT GAGACTTTCCCCACCTTATTATGCATGCAGA 1,931,343-1,929,132 NC_010546.1 ATCC51142 GTGTATCCCCC TGTTATGGGAATTA ACG GGAGATACGTAAAAAAAAAAACCCCGCCC TGTCAGGGGCG GGGTTTTTTTTTGATAAGTCAAGCTATCA GAACCGATC TAATTCCCATAACATCTGCATGCATAATA ACCTTGACAATCATTACACAGCG 555,364-562,941 NC_010546.1 AGGTGGGGAAA GTCTCAGC AATGTATTTCTGATCGATGCGACG CAAATATAATGATCGACATTTTCACCAC 562,897-570,603 NC_010546.1 GTTATCTGGCTGATGTTTGTGGTG CGTTAACTTTGTCGCAAAACTTCG 570,558-577,494 NC_010546.1 GTCAAACTGTCTTGTTTAAAGCCG ACCAAGGCGAATCTCCTTCCTCGGTTCGCGA 577,449-584,687 NC_010546.1 TCACGCTACTCCGC CAATAAAAAAGCCCCCGGAATGATCTTCCGG GGGCCAGATTCAGG TAACTGCTCAAG Azospirillum TTAAGGTCATGCAGCAGGAGAACTAAAGG TGCGTCTTCTTCGGGCATCGTCA 1.043,795-1,035,568 CP012914 brasilense CCCGCGTTAGG Sp7 TTGGTAATAAAAAAGCCCCCGGAATGATC TTCCGGGGGCC CTGCGCAAATACAACATCGAGATC GACGACTGAATAAGGATCGCGGAATG AGAAAATTGATTGCGGACGAGCG 1,035,614-1,027,483 CP012914 TATGTCACAGGCCCGACAAAGCG TTCAATAAGTTAAGCAGATCGGCCTCG 1,027,533-1,019,166 CP012914 GATTGTCGGGTATCGCACACGAG CGGTGTTACGAATAAATATTTCTACGAATAG 1,019,211-1,010,628 CP012914 AC CGAAGGAGTTCGCCCCAGTCTATTC GCTCCAAAAGGAGCCTTTAATTGTATCGGTT 1,010,677-1,003,838 CP012914 TATCAGCTTGCTTT GTTCCGCGGGTCTCGATACAACG Rhodopseudomonas AATACGATCGCATGTCCTAGGTAATACGA GGTCTTGCGGATCATCACTTTC 5,215,514-5,207,699 NC_005296.1 palustris CTCACTATAGG CGA009 GAGAGGTAATCAGTGGTGGATTTGATGT CCAAGCAAAGGACCACCCTC GACGGTCAGGTGGTCCGAAC 5,207,743-5,201,639 NC_005296.1 AGCTTCGATATCATCCGCTGAT GGTGAGAATGATCATGATCGGCC 5,201,687-5,196,113 NC_005296.1 TTGTTCATGTCGGACCTAACCGA CTCCAAAAGGAGCCTTTAATTGTATCGGTTT 5,196,162-5,187,847 NC_005296.1 ATCAGCTTGCTTTG ACGACAAGTGGAGAAGGGATAG Rhodobacter CAATACGATCGCATGTCCTAGGTAATACG TCCCATGGTCATGTCCTTTGCG 2,285,634-2,279,216 NC_007493 sphaeroides ACTCACTATAG 2.4.1. GGAGATGCATTTCACGCTTCGCGATTC CCGCCTTCACCAGAGACACC GTGCGCTTTTCCACGAGGAGC 2,279,260-2,271,404 NC_007493 ATCGAGAAGTTCTACGATGCCGT AATTGAAAAAAAAAACCCCGCCCTGTCAGGG 2,271,450-2,264,419 NC_007493 GCGGGGTTTTTTTT TGCAGCGCCCATTCCGTCTTC GCAAAAAAAAACCCCGCCCCTGACAGGGC GCTCCAAAAGGAGCCTTTAATTGTATCGGTT 245,956-252,936 NC_007494 GGGGTTTTTTT TATCAGCTTGCTTT TTTCAATTGGACCTGGATGGGCAGCAAG GGAGAAAGCCTGCGCGGCTAG Azorhizobium CTCGCATCCATTCTCAGGCTGTCTCGTCT GCCCCCGGAAGGTGATCTTCCGGGGGCTTTC 5,290,244-5,293,483 NC_009937 caulinodans CGTCTCTCTAG TCATGCGTTGA ORS571 AGTCGGAGCTCTTGGGGCCTCTAAACGGG CAGCCTTGAGATAGATCAAGTGC TCTTGAGGGGT TTTTTGTTGTCTTCGACGCGAAGCTC ATAGGCAATACGATCGCATGTCCGTTTAA CTGATCCAGGCCTTCATCGG 1,183,854-1,175,614 NC_009937 ACTGATAAGGA CGGCACTGGCTGG CGATGCCGTCCAGCACCTC GACATGTCTGGTCTCCTTGGAAC 1,175,653-1,170,712 NC_009937 CTGCCACGGTTCCCAAGGTTC TTCTGGAATTTGGTACCGAGTCAGTAACGTG 1,179,751-1,162,529 NC_009937 CCACAGCCTCG TAAAAAAGCGGCTAACCACGCCGCTTTTT ATCAGGCGCATATTTGAATGTATTTACTGCA 3,922,323-3,919,341 NC_009937 TTACGTCTGCA GCGGCCGCTAC GTGTTGTCGAAGCTTGATGCGC GTACTTGTGGGGTCAGTTCCGGCTGGGGGTT CAGCAGCCACC TGCAGTTAATTAAGGCGCTCCTTTCCTGATT CG CGCTGCTTAAGGTCATGCAGCAGGAGAAC GCTGCTGTGTGGAGAGATCG 3,930,607-3,934,260 NC_009937 TAAAGGCCCGC TCTGCGAAAGGAATAGCGTC CTATCGCCGCCACCTGACC GTCGGTGAGATTGATCATGGCC 3,934,220-3,937,923 NC_009937 CGTCAGAACGGCTCTGACGCATCAGGGAG TGCATGTCCGTTCCTCGCTG 3,937,871-3,941,205 NC_009937 A AGTAATATTGCGGATCGGCCAGCAGCGAG ACATGTCTTGAATTCCTTCGAACC 3,941,164-3,959,444 NC_009937 GAA GGTGGTCATTGGCAACGGTTCGAAG TGCATTGCGTTCGCTCCC 3,959,405-3,962,598 NC_009937 TCCCCAAGAGCCCAACCGTTCCGGGAGCG TGTCAGGGCAGGCAGGGCC 3,962,559-3,966,562 NC_009937 AA Gluconacetobacter TTAAGGTCATGCAGCAGGAGAACTAAAGG TCACCAGCCGTATCCGGAATATGTCAGGATC 1,759,465-1,754,718 CP001189 diazotrophicus CCCGCGTTAGG ATGACATCCC PA1 5 TTGGTAATAAAAAAGCCCCCGGAATGATC TTCCGGGGGCC GATCGAGGAAATCGACGTG ATATTCCGGATACGGCTGGTGAGGTGGA ACGATTTCCATGCCCAGGTC 1,754,739-1,746,565 CP001189 CGCCACGTCGTCAATGCCTATAAC CCTCCAGCACCTCTTCGATG 1,746,608-1,738,322 CP001189 TGACCACCGTGCAGAAGATCC GCTCCAAAAGGAGCCTTTAATTGTATCGGTT 1,738,366-1,730,601 CP001189 TATCAGCTTGC TTTGGGCAATACCTGAGACGTTTCA

TABLE-US-00003 TABLE 3 Strains used in this study Name Strain Source Description MR1 E. coli DH10-beta NEB Cat# C3019 MR2 E. coli K-12 MG1655 Voigt lab MR3 Klebsiella oxytoca M5al Voigt lab MR4 Pseudomonas stutzeri A1501 Poole lab MR5 Azotobacter vinelandii DJ Peters lab MR6 Pseudomonas protegens Pf-5 ATCC BAA-477 MR7 P. protegens Pf-5 controller (P.sub.tac-T7RNAP) This study generated by pMR86 MR8 P. protegens Pf-5 controller v1 (P.sub.tac-nifA) This study generated by pMR97 MR9 P. protegens Pf-5 controller v2 (P.sub.tac-nifA v2) This study generated by pMR98 MR10 P. protegens Pf-5 controller v3 (P.sub.tac-nifA v3) This study generated by pMR99 MR11 P. protegens Pf-5 controller v4 (P.sub.BAD.10-nifA) This study generated by pMR100 MR12 P. protegens Pf-5 controller v5 (P.sub.Fde-nifA) This study generated by pMR101 MR13 Rhizobium sp. IRBG74 Ane lab MR14 R. sp. IRBG74 .DELTA.hsdR This study generated by pMR44 MR15 R. sp. IRBG74 .DELTA.recA This study generated by pMR47 MR16 R. sp. IRBG74 .DELTA.nif This study generated by pMR45-46. Two nif clusters (227,127- 219,579 and 234,635-234,802) were removed. MR17 R. sp. IRBG74 .DELTA.hsdR, recA This study MR18 R. sp. IRBG74 .DELTA.hsdR, .DELTA.nif This R. sp. IRBG74 .DELTA.hsdR, recA .DELTA.nif study MR19 R. sp. IRBG74 .DELTA.hsdR .DELTA.nif .DELTA.recA::P.sub.A1lacO1-T7RNAP This generated by pMR82 v1 study MR20 This study MR21 R. sp. IRBG74 .DELTA.hsdR .DELTA.nif .DELTA.recA::P.sub.A1lacO1-T7RNAP This study generated by pMR83 v2 MR22 R. sp. IRBG74 .DELTA.hsdR .DELTA.nif .DELTA.recA::P.sub.A1lacO1-T7RNAP This study generated by pMR84 v3 MR23 R. sp. IRBG74 .DELTA.hsdR .DELTA.nif .DELTA.recA::P.sub.Phl-T7RNAP This study generated by pMR85 MR24 Azorhizobium coulinodans ORS571 Poole lab MR25 Azorhizobium coulinodans ORS571 .DELTA.nifA This study generated by pMR48 MR26 R. spp NGR234 Poole lab MR27 R. leguminosarum bv. Trifolii WSM1325 Poole lab MR28 Sinorhizobium medicae WSM419 Poole lab MR29 R. leguminosarum 8002 Poole lab MR30 Sinorhizobium meliloti WSM1022 Poole lab MR31 R. leguminosarum A34 Poole lab MR32 Sinorhizobium fredii HH103 Poole lab MR33 Sinorhizobium meliloti 1021 Poole lab MR34 R. tropici CIAT899 Poole lab MR35 R. leguminosarum viciae 3841 Poole lab MR36 R. etli CFN42 Poole lab MR37 Agrobacterium tumefaciens C58 Poole lab

TABLE-US-00004 TABLE 4 Plasmids used in this study Origin of Name replication Marker Description pMR1 pBBR1 Kanamycin Plasmid for nif cluster cloning pMR2 pRO1600, Gentamicin Plasmid for nif cluster cloning p15A pMR3 pBBR1 Kanamycin Native nif cluster of K. oxytoca M5al pMR4 pRO1600, Gentamicin Native nif cluster of K. oxytoca M5al p15A pMR5 pBBR1 Kanamycin Native nif cluster of P. stutzeri A1501 pMR6 pRO1600, Gentamicin Native nif cluster of P. stutzeri A1501 p15A pMR7 pBBR1 Kanamycin Native nif cluster of A. vinelandii DJ pMR8 pRO1600, Gentamicin Native nif cluster of A. vinelandii DJ p15A pMR9 pBBR1 Gentamicin Native nif cluster of Cyanothece ATCC51142 pMR10 pRO1600, Gentamicin Native nif cluster of Cyanothece ATCC51142 p15A pMR11 pBBR1 Kanamycin Native nif cluster of P. polymyxa WLY78 pMR12 pRO1600, Gentamicin Native nif cluster of P. polymyxa WLY78 ColE1 pMR13 pBBR1 Kanamycin Native nif cluster of A. brasilense Sp7 pMR14 pRO1600, Gentamicin Native nif cluster of A. brasilense Sp7 ColE1 pMR15 pBBR1 Kanamycin Native nif cluster of R. sphaeroides 2.4.1 pMR16 pRO1600, Gentamicin Native nif cluster of R. sphaeroides 2.4.1 ColE1 pMR17 pBBR1 Kanamycin Native nif cluster of R. palustris CGA009 pMR18 pRO1600, Gentamicin Native nif cluster of R. palustris CGA009 ColE1 pMR19 pBBR1 Kanamycin Native nif cluster of A. caulinodans ORS571 (Part1 of 2) pMR20 RK2 Tetracycline Native nif cluster of A. caulinodans ORS571 (Part2 of 2) pMR21 pBBR1 Kanamycin Native nif cluster of G. diazotrophicus PA1 5 pMR22 pRO1600, Gentamicin Native nif cluster of G. diazotrophicus PA1 5 ColE1 pMR23 pRO1600, Gentamicin nifLA (3,915,521-3,918,529) deletion in the nif cluster of K. oxytoca M5al p15A pMR24 pRO1600, Gentamicin nifLA (1,420,874-1,423,084) deletion in the nif cluster of P. stutzeri A1501 p15A pMR25 pRO1600, Gentamicin nifLA (5,168,709-5,171,731) deletion in the nif cluster of A. vinelandii DJ p15A pMR26 pRO1600, Gentamicin Native nif cluster of A. vinelandii DJ with the rnf2 operon p15A pMR27 pRO1600, Gentamicin rnf1 (5,168,156-5,162,716) operon deletion in the nif cluster of A. vinelandii DJ p15A pMR28 pRO1600, Gentamicin fix operon (995,860-1,000,698) deletion in the nif cluster of A. vinelandii DJ p15A pMR29 pBBR1 Kanamycin Refactored nif cluster v2.1 pMR30 pRO1600, Gentamicin Refactored nif cluster v2.1 p15A pMR31 RK2 Tetracycline Refactored nif cluster v2.1 pMR32 ColE1 Gentamicin P.sub.WT-nifHDKTY pMR33 ColE1 Gentamicin P.sub.2-nifENX pMR34 ColE1 Gentamicin P.sub.2-nifJ pMR35 ColE1 Gentamicin P.sub.2-nifBQ pMR36 ColE1 Gentamicin P.sub.2-nifF pMR37 ColE1 Gentamicin P.sub.2-nifUSVWZM pMR38 pBBR1 Kanamycin Refactored nif cluster v3.2 pMR39 pRO1600, Gentamicin Refactored nif cluster v3.2 p15A pMR40 pBBR1 Kanamycin LacI, P.sub.A1lacO1-gfpmut3b pMR41 RSF1010 Gentamicin LacI, P.sub.A1lacO1-gfpmut3b pMR42 RK2 Tetracycline LacI, P.sub.tac-gfpmut3b pMR43 pRO1600, Gentamicin LacI, P.sub.A1lacO1-gfpmut3b ColE1 pMR44 p15A Gentamicin Suicide plasmid for hsdR deletion in R. sp. IRBG74 pMR45 p15A Gentamicin Suicide plasmid for the nif cluster I (219,579-227,127) deletion in R. sp. IRBG74 pMR46 p15A Gentamicin Suicide plasmid for the nif cluster II (234,635-234,802) deletion in R. sp. IRBG74 pMR47 p15A Gentamicin Suicide plasmid for recA deletion in R. sp. IRBG74 pMR48 p15A Gentamicin Suicide plasmid for nifA deletion in A. coulinodans ORS571 pMR49 pBBR1 Gentamicin LacI, P.sub.A1lacO1-nifV (A. coulinodans ORS571) pMR50 pBBR1 Gentamicin P.sub.nifH(R. sp. IRBG74)-sfgfp pMR51 pBBR1 Gentamicin NifA(R. sp. IRBG74), P.sub.nifH(R. sp. IRBG74)-sfgfp pMR52 pBBR1 Gentamicin NifA(K. oxytoca), P.sub.nifH(K. oxytoca)-sfgfp pMR53 pBBR1 Gentamicin NifA(R. sp. IRBG74), P.sub.nifH(K. oxytoca)-sfgfp pMR54 pBBR1 Gentamicin NifA(P. stutzeri), P.sub.nifH(P. stutzeri)-sfgfp pMR55 pBBR1 Gentamicin NifA(R. sp. IRBG74), P.sub.nifH(P. stutzeri)-sfgfp pMR56 pBBR1 Gentamicin NifA(A. coulinodans), P.sub.nifH(A. coulinodans)-sfgfp pMR57 pBBR1 Gentamicin NifA(R. sp. IRBG74), P.sub.nifH(A. coulinodans)-sfgfp pMR58 pBBR1 Kanamycin Plasmid for consituitive promoter characterization. P.sub.constitutive-gfpmut3b pMR59 pRO1600, Gentamicin Plasmid for consituitive promoter characterization. P.sub.constitutive-gfpmut3b p15A pMR60 pBBR1 Kanamycin PT7(WT)-mCherry pMR61 pBBR1 Kanamycin PT7(P1)-mCherry pMR62 pBBR1 Kanamycin PT7(P2)-mCherry pMR63 pBBR1 Kanamycin PT7(P3)-mCherry pMR64 pBBR1 Kanamycin PT7(P4)-mCherry pMR65 pBBR1 Kanamycin PT7(P5)-mCherry pMR66 pRO1600, Gentamicin AraE, AraC, P.sub.BAD.10-gfpmut3b ColE1 pMR67 pBBR1 Kanamycin Plasmid for terminator characterization. P.sub.T7-gfpmut3b-mrfp1 pMR68 pRO1600, Gentamicin Plasmid for terminator characterization. P.sub.T7-gfpmut3b-mrfp1 ColE1 pMR69 pBBR1 Kanamycin LuxR, P.sub.Lux-gfpmut3b pMR70 pBBR1 Kanamycin TetR, P.sub.Tet-gfpmut3b pMR71 pBBR1 Kanamycin CymR, P.sub.Cym-gfpmut3b pMR72 pBBR1 Kanamycin PhlF, P.sub.Phl-gfpmut3b pMR73 pBBR1 Kanamycin NahR, P.sub.Sal-gfpmut3b pMR74 pRO1600, Gentamicin PhlF, P.sub.Phl-gfpmut3b ColE1 pMR75 pRO1600, Gentamicin TetR, P.sub.Tet-gfpmut3b ColE1 pMR76 pRO1600, Gentamicin LuxR, P.sub.Lux-gfpmut3b ColE1 pMR77 pRO1600, Gentamicin CymR, P.sub.Cym-gfpmut3b ColE1 pMR78 pRO1600, Gentamicin FdeR, P.sub.Fde-gfpmut3b ColE1 pMR79 pRO1600, Gentamicin LacI(Q18M/A47V/F161Y), P.sub.tac-gfpmut3b ColE1 pMR80 pBBR1 Kanamycin P.sub.T7-gfpmut3b pMR81 pRO1600, Gentamicin P.sub.T7-gfpmut3b p15A pMR82 p15A Gentamicin Controller for R. sp. IRBG74, LacI, P.sub.A1lacO1-T7RNAP (RBSr33 for T7RNAP) pMR83 p15A Gentamicin Controller for R. sp. IRBG74, LacI, P.sub.A1lacO1-T7RNAP (RBSr32 for T7RNAP) pMR84 p15A Gentamicin Controller for R. sp. IRBG74, LacI, P.sub.A1lacO1-T7RNAP (RBSr3 for T7RNAP) pMR85 p15A Gentamicin Controller for R. sp. IRBG74, PhlF, P.sub.PhlF-T7RNAP (RBSr33 for T7RNAP) pMR86 ColE1 Tetracycline Controller for P. protegens Pf-5, LacI(Q18M/A47V/F161Y), P.sub.tac-T7RNAP pMR87 pBBR1 Kanamycin NocR, P.sub.noc-gfpmut3b pMR88 pBBR1 Kanamycin OccR, P.sub.ooc-gfpmut3b pMR89 pBBR1 Gentamicin NifA(A. vinelandii), P.sub.nifH(A. vinelandii)-sfgfp pMR90 pBBR1 Gentamicin NifA(K. oxytoca),P.sub.nifH(P. stutzeri)-sfgfp pMR91 pBBR1 Gentamicin NifA(K. oxytoca), P.sub.nifH(A. vinelandii)-sfgfp pMR92 pRO1600, Gentamicin NifA(K. oxytoca), P.sub.nifH(K. oxytoca)-sfgfp p15A pMR93 pRO1600, Gentamicin NifA(A. vinelandii), P.sub.nifH(A. vinelandii)-sfgfp p15A pMR94 pRO1600, Gentamicin NifA(P. stutzeri), P.sub.nifH(P. stutzeri)-sfgfp p15A pMR95 pRO1600, Gentamicin NifA(P. stutzeri), P.sub.nifH(K. oxytoca)-sfgfp p15A pMR96 pRO1600, Gentamicin NifA(P. stutzeri), P.sub.nifH(A. vinelandii)-sfgfp p15A pMR97 ColE1 Tetracycline NifA controller for P. protegens Pf-5, LacI(Q18M/A47V/F161Y), P.sub.tac-nifA(P. stutzeri) (RBSp32 for NifA) pMR98 ColE1 Tetracycline NifA controller for P. protegens Pf-5, LacI(Q18M/A47V/F161Y), P.sub.tac-nifA(P. stutzeri) (RBSp27 RBS for NifA) pMR99 ColE1 Tetracycline NifA controller for P. protegens Pf-5, LacI(Q18M/A47V/F161Y), P.sub.tac-nifA(P. stutzeri) (RBSp33 for NifA) pMR100 ColE1 Tetracycline NifA controller for P. protegens Pf-5, AraE, AraC, P.sub.BAD.10-nifA pMR101 ColE1 Tetracycline NifA controller for P. protegens Pf-5, FdeR, P.sub.Fde-nifA pMR102 IncW Spectinomycin NifA controller plasmid for E. coli, LacI, P.sub.A1lacO1-nifA(K. oxytoca) pMR103 pRO1600, Gentamicin P.sub.nifH(K. oxytoca)-sfgfp p15A pMR104 pRO1600, Gentamicin P.sub.nifH(P. stutzeri)-sfgfp p15A pMR105 pRO1600, Gentamicin P.sub.nifH(A. vinelandii)-sfgfp p15A pMR106 pBBR1 Gentamicin P.sub.nifH(K. oxytoca)-sfgfp pMR107 pBBR1 Gentamicin P.sub.nifH(P. stutzeri)-sfgfp pMR108 pBBR1 Gentamicin P.sub.nifH(A. vinelandii)-sfgfp pMR109 p15A Kanamycin P.sub.BAD-T7RNAP pMR110 p15A Kanamycin P.sub.Bet-T7RNAP pMR111 p15A Kanamycin P.sub.Cin-T7RNAP pMR112 p15A Kanamycin P.sub.Cym-T7RNAP pMR113 p15A Kanamycin P.sub.Lux-T7RNAP pMR114 p15A Kanamycin P.sub.Phl-T7RNAP pMR115 p15A Kanamycin P.sub.3B5B-T7RNAP pMR116 p15A Kanamycin P.sub.tac-T7RNAP pMR117 p15A Kanamycin P.sub.Tet-T7RNAP pMR118 p15A Kanamycin P.sub.Tfg-T7RNAP pMR119 p15A Kanamycin P.sub.Van-T7RNAP pMR120 p15A Kanamycin P.sub.Sal-T7RNAP pMR121 pBBR1 Gentamicin P.sub.T7(P2)-gfpmut3b pMR122 pBBR1 Gentamicin NifA controller for A. caulinodans, LacI, P.sub.A1lacO1-nifA-rpoN pMR123 pBBR1 Gentamicin NifA controller for A. caulinodans, LacI, P.sub.A1lacO1-nifA(L94Q)-rpoN pMR124 pBBR1 Gentamicin NifA controller for A. caulinodans, LacI, P.sub.A1lacO1-nifA(D95Q)-rpoN(A. caulinodans) pMR125 pBBR1 Gentamicin NifA controller for A. caulinodans, LacI, P.sub.A1lacO1-nifA(L94Q/D95Q)-rpoN pMR126 pBBR1 Gentamicin NifA controller for A. caulinodans, NahR, P.sub.Sal-nifA(L94Q/D95Q)-rpoN pMR127 pBBR1 Gentamicin NifA controller for A. caulinodans, NocR, P.sub.noc-nifA(L94Q/D95Q)-rpoN pMR128 pBBR1 Gentamicin NifA controller for A. caulinodans, OccR, P.sub.occ-nifA(L94Q/D95Q)-rpoN pMR129 pBBR1 Gentamicin P.sub.nifH(A. caulinodans)-sfgfp pMR130 pBBR1 Gentamicin NifA, P.sub.nifH(A. caulinodans)-sfgfp pMR131 pBBR1 Gentamicin NifA, RpoN, P.sub.nifH(A. caulinodans)-sfgfp pMR132 pBBR1 Gentamicin LacI, P.sub.A1lacO1-nifA(L94Q/D95Q)-rpoN, P.sub.nifH-sfgfp pMR133 pBBR1 Gentamicin NahR, PSal-nifA(L940/D95Q)-rpoN, P.sub.nifH-sfgfp pMR134 pBBR1 Gentamicin NocR, Pnoc-nifA(L940/D95Q)-rpoN, P.sub.nifH-sfgfp pMR135 pBBR1 Gentamicin OccR, Pocc-nifA(L94Q/D95Q)-rpoN, P.sub.nifH-sfgfp pMR136 pBBR1 Gentamicin Refactored nif clusterv2.1

TABLE-US-00005 TABLE 5 Genetic part sequences used in this study Name Genetic part DNA sequence (SEQ ID NOs: 122-225) P.sub.A1lacO1 Promoter.sup.6 AGAGTGTTGACTTGTGAGCGGATAACAATGATACTTAGATTCAATTGTGAGCGGATAACAATTTCAC ACA T7 RNAP Gene ATGAACACGATTAACATCGCTAAGAACGACTTCTCTGACATCGAACTGGCTGCTATCCCGTTCAACACTC TGGCTGACCATTACGGTGAGCG TTTAGCTCGCGAACAGTTGGCCCTTGAGCATGAGTCTTACGAGATGGGTGAAGCACGCTTCCGCAAGATG TTTGAGCGTCAACTTAAAGCTG GTGAGGTTGCGGATAACGCTGCCGCCAAGCCTCTCATCACTACCCTACTCCCTAAGATGATTGCACGCAT CAACGACTGGTTTGAGGAAGTG AAAGCTAAGCGCGGCAAGCGCCCGACAGCCTTCCAGTTCCTGCAAGAAATCAAGCCGGAAGCCGTAGCGT ACATCACCATTAAGACCACTCT GGCTTGCCTAACCAGTGCTGACAATACAACCGTTCAGGCTGTAGCAAGCGCAATCGGTCGGGCCATTGAG GACGAGGCTCGCTTCGGTCGTA TCCGTGACCTTGAAGCTAAGCACTTCAAGAAAAACGTTGAGGAACAACTCAACAAGCGCGTAGGGCACGT CTACAAGAAAGCATTTATGCAA GTTGTCGAGGCTGACATGCTCTCTAAGGGTCTACTTGGTGGCGAGGCGTGGTCTTCGTGGCATAAGGAAG ACTCTATTCATGTAGGAGTACG CTGCATCGAGATGCTCATTGAGTCAACCGGAATGGTTAGCTTACACCGCCAAAATGCTGGCGTAGTAGGT CAAGACTCTGAGACTATCGAAC TCGCACCTGAATACGCTGAGGCTATCGCAACCCGTGCAGGTGCGCTGGCTGGCATCTCTCCGATGTTCCA ACCTTGCGTAGTTCCTCCTAAG CCGTGGACTGGCATTACTGGTGGTGGCTATTGGGCTAACGGTCGTCGTCCTCTGGCGCTGGTGCGTACTC ACAGTAAGAAAGCACTGATGCG CTACGAAGACGTTTACATGCCTGAGGTGTACAAAGCGATTAACATTGCGCAAAACACCGCATGGAAAATC AACAAGAAAGTCCTAGCGGTCG CCAACGTAATCACCAAGTGGAAGCATTGTCCGGTCGAGGACATCCCTGCGATTGAGCGTGAAGAACTCCC GATGAAACCGGAAGACATCGAC ATGAATCCTGAGGCTCTCACCGCGTGGAAACGTGCTGCCGCTGCTGTGTACCGCAAGGACAAGGCTCGCA AGTCTCGCCGTATCAGCCTTGA GTTCATGCTTGAGCAAGCCAATAAGTTTGCTAACCATAAGGCCATCTGGTTCCCTTACAACATGGACTGG CGCGGTCGTGTTTACGCTGTGT CAATGTTCAACCCGCAAGGTAACGATATGACCAAAGGACTGCTTACGCTGGCGAAAGGTAAACCAATCGG TAAGGAAGGTTACTACTGGCTG AAAATCCACGGTGCAAACTGTGCGGGTGTCGACAAGGTTCCGTTCCCTGAGCGCATCAAGTTCATTGAGG AAAACCACGAGAACATCATGGC TTGCGCTAAGTCTCCACTGGAGAACACTTGGTGGGCTGAGCAAGATTCTCCGTTCTGCTTCCTTGCGTTC TGCTTTGAGTACGCTGGGGTAC AGCACCACGGCCTGAGCTATAACTGCTCCCTTCCGCTGGCGTTTGACGGGTCTTGCTCTGGCATCCAGCA CTTCTCCGCGATGCTCCGAGAT GAGGTAGGTGGTCGCGCGGTTAACTTGCTTCCTAGTGAAACCGTTCAGGACATCTACGGGATTGTTGCTA AGAAAGTCAACGAGATTCTACA AGCAGACGCAATCAATGGGACCGATAACGAAGTAGTTACCGTGACCGATGAGAACACTGGTGAAATCTCT GAGAAAGTCAAGCTGGGCACTA AGGCACTGGCTGGTCAATGGCTGGCTTACGGTGTTACTCGCAGTGTGACTAAGCGTTCAGTCATGACGCT GGCTTACGGGTCCAAAGAGTTC GGCTTCCGTCAACAAGTGCTGGAAGATACCATTCAGCCAGCTATTGATTCCGGCAAGGGTCTGATGTTCA CTCAGCCGAATCAGGCTGCTGG ATACATGGCTAAGCTGATTTGGGAATCTGTGAGCGTGACGGTGGTAGCTGCGGTTGAAGCAATGAACTGG CTTAAGTCTGCTGCTAAGCTGC TGGCTGCTGAGGTCAAAGATAAGAAGACTGGAGAGATTCTTCGCAAGCGTTGCGCTGTGCATTGGGTAAC TCCTGATGGTTTCCCTGTGTGG CAGGAATACAAGAAGCCTATTCAGACGCGCTTGAACCTGATGTTCCTCGGTCAGTTCCGCTTACAGCCTA CCATTAACACCAACAAAGATAG CGAGATTGATGCACACAAACAGGAGTCTGGTATCGCTCCTAACTTTGTACACAGCCAAGACGGTAGCCAC CTTCGTAAGACTGTAGTGTGGG CACACGAGAAGTACGGAATCGAATCTTTTGCACTGATTCACGACTCCTTCGGTACGATTCCGGCTGACGC TGCGAACCTGTTCAAAGCAGTG CGCGAAACTATGGTTGACACATATGAGTCTTGTGATGTACTGGCTGATTTCTACGACCAGTTCGCTGACC AGTTGCACGAGTCTCAATTGGA CAAAATGCCAGCACTTCCGGCTAAAGGTAACTTGAACCTCCGTGACATCTTAGAGTCGGACTTCGC GTTCGCGTAA P.sub.laclq Promoter.sup.7 CGAATGGTGCAAAACCTTTCGCGGTATGGCATGATAGCGCCCGGAAGAGAG rpoN of A. caulinodans Gene ATGGCGATGAGCCCAAAGATGGAGTTCCGCCAGAGCCAGTCTCTGGTGATGACGCCGCAGCTGATGCAGG CCATCAAGCTGCTGCAGCTCTC CAATCTCGAACTGGTCGCCTATGTGGAGGCCGAGCTCGAACGCAATCCGCTGCTGGAGCGGGCGAGCGAG CCGGAAAGCCCCGAGCACGATC CGCCGAACCCGCAGGAAGAGGCACCCACCCCGCCTGACAGTGGCGCGCCGGTGTCCGGCGACTGGATGGA AAGCGACATGGGCTCGAGCCGC GAGGCCATCGAGACCCGGCTGGACACCGACCTCGGCAATGTCTTTCCCGATGATGCGCCGGCCGAGCGCA TCGGCGCGGGCAGCGGCAGCGG CTCGTCCATCGAATGGGGCTCGGGCGGCGACCGGGGCGAGGACTACAATCCGGAAGCCTTCCTCGCTGCC GAGACGACGCTGGCCGACCATC TGGAAGCCCAGCTCTCCGTGGCGGAGCCCGATCCGGCGCGCCGCCTCATCGGCCTCAACCTCATCGGCCT CATCGACGAGACGGGTTATTTC TCCGGCGACCTCGATGCGGTGGCCGAGCAACTGGGCGCCACCCACGATCAGGTGGCCGACGTGCTGCGCG TCATCCAGAGCTTCGAGCCGTC CGGCGTCGGCGCACGGTCGCTCAGCGAATGCCTGGCCCTGCAATTGCGCGACAAGGATCGCTGCGATCCC GCCATGCAGGCGCTGCTCGACA ATCTGGAACTCCTCGCCCGCCACGACCGCAACGCGCTGAAGCGCATCTGCGGGGTGGACGCGGAAGACCT CGCGGACATGATCGGCGAGATC CGCCGCCTCGATCCGAAGCCCGGCCTCGCCTATGGCGGCGGCGTCGTCCACCCGCTGGTGCCGGACGTGT TCGTGCGCGAGGGCTCCGACGG CAGCTGGATCGTGGAACTGAATTCCGAGACGCTGCCGCGCGTGCTGGTGAACCAGACCTATCACGCGACG GTGGCCAAGGCGGCGCGCTCGG CCGAGGAAAAGACCTTCCTCGCCGACTGCCTCCAGAGCGCCTCCTGGCTTACCCGCTCGCTCGACCAGCG GGCTCGCACCATCCTCAAGGTG GCGAGCGAGATCGTGCGCCAGCAGGACGCCTTCCTCGTGCACGGCGTGCGGCACCTGCGCCCCCTGAACC TGCGCACGGTGGCGGATGCCAT CGGCATGCACGAATCCACCGTCTCGCGGGTGACCTCGAACAAGTACATCTCCACCCCGCGCGGGGTGCTG GAGATGAAGTTCTTCTTCTCCT CCTCCATCGCTTCCTCGGGTGGTGGCGAGGCCCATGCGGCGGAGGCGGTGCGCCACCGCATCAAGAGCCT CATCGAGGCCGAGAGTGCGGAC GACGTGCTGTCCGACGACACGCTGGTGCAGAAGCTGAAGGACGACGGCATCGATATCGCCCGCCGAACGG TCGCGAAATATCGCGAGAGCAT GAACATCCCGTCCTCGGTCCAGCGCCGCCGCGAAAAGCAGGCCCTGCGCAGCGACGCCGCCGCCGC CGGCTGA lacl Gene GTGAAACCAGTAACGTTATACGATGTCGCAGAGTATGCCGGTGTCTCTTATCAGACCGTTTCCC- GCGTGG TGAACCAGGCCAGCCACGTTTC TGCGAAAACGCGGGAAAAAGTGGAAGCGGCGATGGCGGAGCTGAATTACATTCCCAACCGCGTGGCACAA CAACTGGCGGGCAAACAGTCGT TGCTGATTGGCGTTGCCACCTCCAGTCTGGCCCTGCACGCGCCGTCGCAAATTGTCGCGGCGATTAAATC TCGCGCCGATCAACTGGGTGCC AGCGTGGTGGTGTCGATGGTAGAACGAAGCGGCGTCGAAGCCTGTAAAGCGGCGGTGCACAATCTTCTCG CGCAACGCGTCAGTGGGCTGAT CATTAACTATCCGCTGGATGACCAGGATGCCATTGCTGTGGAAGCTGCCTGCACTAATGTTCCGGCGTTA TTTCTTGATGTCTCTGACCAGA CACCCATCAACAGTATTATTTTCTCCCATGAAGACGGTACGCGACTGGGCGTGGAGCATCTGGTCGCATT GGGTCACCAGCAAATCGCGCTG TTAGCGGGCCCATTAAGTTCTGTCTCGGCGCGTCTGCGTCTGGCTGGCTGGCATAAATATCTCACTCGCA ATCAAATTCAGCCGATAGCGGA ACGGGAAGGCGACTGGAGTGCCATGTCCGGTTTTCAACAAACCATGCAAATGCTGAATGAGGGCATCGTT CCCACTGCGATGCTGGTTGCCA ACGATCAGATGGCGCTGGGCGCAATGCGCGCCATTACCGAGTCCGGGCTGCGCGTTGGTGCGGATATCTC GGTAGTGGGATACGACGATACC GAAGACAGCTCATGTTATATCCCGCCGTTAACCACCATCAAACAGGATTTTCGCCTGCTGGGGCAAACCA GCGTGGACCGCTTGCTGCAACT CTCTCAGGGCCAGGCGGTGAAGGGCAATCAGCTGTTGCCCGTCTCACTGGTGAAAAGAAAAACCACCCTG GCGCCCAATACGCAAACCGCCT CTCCCCGCGCGTTGGCCGATTCATTAATGCAGCTGGCACGACAGGTTTCCCGACTGGAAAGCGGGC AGTGA gfpmut3b Gene ATGAGTAAAGGAGAAGAACTTTTCACTGGAGTTGTCCCAATTCTTGTTGAATTAGATGGTGATGTTAATG GGCACAAATTTTCTGTTAGTGG AGAGGGTGAAGGTGATGCAACATACGGAAAACTTACCCTTAAATTTATTTGCACTACTGGAAAACTACCT GTTCCATGGCCAACACTTGTCA CTACTTTCGGTTATGGTGTTCAATGCTTTGCGAGATACCCAGATCATATGAAACAGCATGACTTTTTCAA GAGTGCCATGCCCGAAGGTTAT GTACAGGAAAGAACTATATTTTTCAAAGATGACGGGAACTACAAGACACGTGCTGAAGTCAAGTTTGAAG GTGATACCCTTGTTAATAGAAT CGAGTTAAAAGGTATTGATTTTAAAGAAGATGGAAACATTCTTGGACACAAATTGGAATACAACTATAAC TCACACAATGTATACATCATGG CAGACAAACAAAAGAATGGAATCAAAGTTAACTTCAAAATTAGACACAACATTGAAGATGGAAGCGTTCA ACTAGCAGACCATTATCAACAA AATACTCCAATTGGCGATGGCCCTGTCCTTTTACCAGACAACCATTACCTGTCCACACAATCTGCCCTTT CGAAAGATCCCAACGAAAAGAG AGACCACATGGTCCTTCTTGAGTTTGTAACAGCTGCTGGGATTACACATGGCATGGATGAACTATA CAAATAG sigfg Gene ATGCGTAAAGGCGAAGAGCTGTTCACTGGTGTCGTCCCTATTCTGGTGGAACTGGATGGTGAT- GTCAACGGTCATAAGTTTTCC GTGCGTGG CGAGGGTGAAGGTGACGCAACTAATGGTAAACTGACGCTGAAGTTCATCTGTACTACTGGTAAACTGCCGGT- ACCTTGGCCGAC TCTGGTAA CGACGCTGACTTATGGTGTTCAGTGCTTTGCTCGTTATCCGGACCATATGAAGCAGCATGACTTCTTCAAGT- CCGCCATGCCGG AAGGCTAT GTGCAGGAACGCACGATTTCCTTTAAGGATGACGGCACGTACAAAACGCGTGCGGAAGTGAAATTTGAAGGC- GATACCCTGGTA AACCGCAT TGAGCTGAAAGGCATTGACTTTAAAGAAGACGGCAATATCCTGGGCCATAAGCTGGAATACAATTTTAACAG- CCACAATGTTTA CATCACCG CCGATAAACAAAAAAATGGCATTAAAGCGAATTTTAAAATTCGCCACAACGTGGAGGATGGCAGCGTGCAGC- TGGCTGATCACT ACCAGCAA AACACTCCAATCGGTGATGGTCCTGTTCTGCTGCCAGACAATCACTATCTGAGCACGCAAAGCGTTCTGTCT- AAAGATCCGAAC GAGAAACG CGATCATATGGTTCTGCTGGAGTTCGTAACCGCAGCGGGCATCACGCATGGTATGGATGAACTGTACAAATG- A mrfp1 Gene ATGGCTTCCTCCGAAGACGTTATCAAAGAGTTCATGCGTTTCAAAGTTCGTATGGAAGGTTCC- GTTAACGGTCACGAGTTCGAA ATCGAAGG TGAAGGTGAAGGTCGTCCGTACGAAGGTACCCAGACCGCTAAACTGAAAGTTACCAAAGGTGGTCCGCTGCC- GTTCGCTTGGGA CATCCTGT CCCCGCAGTTCCAGTACGGTTCCAAAGCTTACGTTAAACACCCGGCTGACATCCCGGACTACCTGAAACTGT- CCTTCCCGGAAG GTTTCAAA TGGGAACGTGTTATGAACTTCGAAGACGGTGGTGTTGTTACCGTTACCCAGGACTCCTCCCTGCAAGACGGT- GAGTTCATCTAC AAAGTTAA ACTGCGTGGTACCAACTTCCCGTCCGACGGTCCGGTTATGCAGAAAAAAACCATGGGTTGGGAAGCTTCCAC- CGAACGTATGTA CCCGGAAG ACGGTGCTCTGAAAGGTGAAATCAAAATGCGTCTGAAACTGAAAGACGGTGGTCACTACGACGCTGAAGTTA- AAACCACCTACA TGGCTAAA AAACCGGTTCAGCTGCCGGGTGCTTACAAAACCGACATCAAACTGGACATCACCTCCCACAACGAAGACTAC- ACCATCGTTGAA CAGTACGAACGTGCTGAAGGTCGTCACTCCACCGGTGCTTAA mCherry Gene ATGGTTTCGAAGGGCGAGGAGGATAACATGGCCATCATCAAGGAGTTCATGCGCTTCAAGGTGCACATGGAGG- GCTCCGTGAAC GGCCACGA GTTCGAGATCGAGGGCGAGGGCGAGGGCCGCCCCTACGAGGGCACCCAGACCGCCAAGCTGAAGGTGACCAA- GGGTGGCCCCCT GCCCTTCG CCTGGGACATCCTGTCCCCTCAGTTCATGTACGGCTCCAAGGCCTACGTGAAGCACCCCGCCGACATCCCCG- ACTACTTGAAGC TGTCCTTC CCCGAGGGCTTCAAGTGGGAGCGCGTGATGAACTTCGAGGACGGCGGCGTGGTGACCGTGACCCAGGACTCC- TCCTTGCAGGAC GGCGAGTT CATCTACAAGGTGAAGCTGCGCGGCACCAACTTCCCCTCCGACGGCCCCGTAATGCAGAAGAAGACGATGGG- CTGGGAGGCCTC CTCCGAGC GGATGTACCCCGAGGACGGCGCCCTGAAGGGCGAGATCAAGCAGAGGCTGAAGCTGAAGGACGGCGGCCACT- ACGACGCTGAGG TCAAGACC ACCTACAAGGCCAAGAAGCCCGTGCAGCTGCCCGGCGCCTACAACGTCAACATCAAGTTGGACATCACCTCC- CACAACGAGGAC TACACCATCGTGGAACAGTACGAACGCGCCGAGGGCCGCCACTCCACCGGCGGCATGGACGAGCTGTACAAG- TAA P.sub.WT Promoter.sup.8 TAATACGACTCACTATAGGGAGA P.sub.1 Promoter.sup.8 TAATACGACTCACTACAGGCAGA P.sub.2 Promoter.sup.8 TAATACGACTCACTAGAGAGAGA P.sub.3 Promoter.sup.8 TAATACGACTCACTAATGGGAGA P.sub.4 Promoter.sup.8 TAATACGACTCACTAAAGGGAGA P.sub.5 Promoter.sup.8 TAATACGACTCACTATAGGTAGA P.sub.6 Promoter.sup.8 TAATACGACTCACTATTGGGAGA nifV of A. caulinodans Gene GTGTTCCGTGGGAGGCCTGCCATGCTCGCCAAGACACCCGCAAACCCCGCGCCGCTTCAGCGGACGGCGTTCC- TGAACGACACC ACGCTGCG CGACGGCGAGCAGGCGCCGGGTGTCGCCTTCACCCGCAAGGAGAAGATCGAGATCGCCGCCGCCCTTGCCGC- CGCCGGTGTCCC GGAGATCG AGGCGGGAACGCCCGCCATGGGCGACGAAGAGGTGGAAACCATCCGCTCCATCGTCTCGCTGAACCTCCCGA- CGCGCGTCATGG CCTGGTGC CGCATGAGCGAGGACGACCTGATGGCCGCCGTCGCGGCGGGCGTGAAGATCGTCAATGTCTCCATTCCCACC- TCCGACCGGCAA CTGGCCGG CAAGCTCGGCAAGGATCGCGCCTGGGCGCTCGGCCGTGTGGCGGAGGTGGTGACACTGGCGCGTCGGCTCGG-

CTTTGAGGTGGC GGTAGGGG GCGAGGATTCCTCGCGGGCCGATCCCGATTTTCTCTGCCGTCTCGCGGAGACGGCGAAGGCGGCGGGCGCCT- TTCGCCTGCGGC TGGCCGAC ACGCTTGGCGTGCTTGACCCCTTCGGCACCTATGCATTGGTGCGCCGGGTGGCCGCCACCACCGACATCGAG- CTTGAGTTCCAC GCCCATGA CGATCTCGGCCTTGCCACCGCCAATACGCTGGCGGCGGTGATGGGCGGAGCGCGTCACGCCAGCGTCACCGT- CGCCGGGCTCGG CGAGCGCG CGGGCAATGCCGCGCTGGAGGAAGTGGCCATCGCCCTGCGCCAGACGGCGCGGGCGGAGACCGGCATCGCTC- CGGCCGCGCTGA AGCCGCTG GCCGAACTAGTGTGCGGCGCCGCCGCCCGTCCGGTGCCGCGCGGCAAGGCCATCGTCGGCGCGGATGTGTTC- ACCCACGAGTCG GGCATCCA TGTCTCCGGCCTGCTCAAGGACCGGGCCACCTATGAAGCTCTGAATCCGGAACTGTTCGGGCGTGGCCACAC- GGTGGTGCTCGG AAAGCATT CCGGTCTTGCGGCGGTGGAGAAGGCGCTGGCCGACGAGGGCATCACCGTGGATGCGGTGCGCGGGCGCGCCA- TTCTCGACCGGG TGCGGGCT TTTGCTGTCCGCACCAAGGAGAATGTTTCCCGCGAGACGCTGCTGCGCTTCTATCAGGACAGCTTCACCGAG- TCCGCGCTGCGT CTGCGGCGGGCCGCCGTGGAAGGCGCAATCTGA P.sub.nifh of K. oxytoca Promoter TGTTGCCTCAAGCACAGCCTGTGCCAGCTCGCGGATGACAGAAGAGTTAGCGCGAATTCAACGCGTTATGAAG- AGAGTCGCCGC GCAGCGCG CCAAGAGATTGCGTGGAATAAGACACAGGGGGCGACAAGCTGTTGAACAGGCGACAAAGCGCCACCATGGCC- CCGGCAGGCGCA ATTGTTCT GTTTCCCACATTTGGTCGCCTTATTGTGCCGTTTTGTTTTACGTCCTGCGCGGCGACAAATAACTAACTTCA- TAAAAATCATAA GAATAC ATAAACAGGCACGGCTGGTATGTTCCCTGCACTTCTCTGCTGGCAAACA P.sub.nifh of P. stutzeri Promoter TGTCATGTTCGCAACAGTTGCCGAAAGTGTGGAAAACCGGCGCTTGGCCCGGCCGATCTTTTTGTCGCCATTG- CAACAGTCAGG CCTGTCGG TTGTTAACTATCGAACCGCCGAAGGATGTTGCTAGTAATTAAATTATTCTAATTAAAACAAGTGCTTAGATT- ATTTTAGAAACG CTGGCACAAAGGCTGCTATTGCCCTGTTGCGCAGGCTTGTTCGTGCCTATAGCCCAC P.sub.nifh of A. vinelandii Promoter TGTCAGTTTTGTCACAGGGGGCCGGACCAGGATGGTGGACGCTCGATGGGGATGTCGGGCCATTGTTCGGTTG- TAGCAATTACA ACAGTCGG AGTAGGGGGATTGTAGGGGGATTGTTGTGTATCAGACCGCCCTGCAGCTCCCGTCGATGGATAATTAATCAT- TTAAAATCAATG GTTTATTT ATGTGTTGCGGGTGCTGGCACAGACGCTGCATTACCTTTGGTGCGCGGAGTTGTTCGGGCTTACGGCCGAAC P.sub.nifh of R. sp. Promoter TTGACAAAGCCTCCGAGAAGAGCGCCCCCTAACCCCTCCTCAGCCCTGATCGGCAGTATCATCTTGTCGAATC- CTAACGTCTGA IRBG74 TAGGCAAC GCTATACGACAAACGCTGGTTACAATTGTCGGTTCCGCGACAAGAATTTGCTTTGTCTGGCGGGTGGTCTAT- TTTGAGCTAAGT AGCTGAGA AATCAGGAAAACAAAACTCTATTCGGTCTACCCGACGAGTTGGCACGGGTCTTGTAACCATCCTTGCGCAGG- CGGCGAAAGCCA CCGGCGATATTCATGTTGCGGGCAAC P.sub.nifh of Of A. caulinodans Promoter TGTCGCGTTTGAAACACGGGGCTTTTGGAACCGTTCGATTCTGCAATGCACTGATTTTACTTGATTAATTCGA- CCACACGACCA CTGGCACA CCCGTTGCAAAACCCCTTGGTGCAGGCGACGGGTTGCCGGTCTGGTTCGCGGATCTCCTCGATCCCCGGCTA- CCGACCCGCCTC CGAAAAGTCCGGTCCCGATCCAGTTCGGCGGGGCCACAC nifA of K. oxytoca Gene ATGATCCATAAATCCGATTCGGACACCACCGTCAGACGTTTCGATCTCTCCCAGCAGTTTACCGCCATGCAGC- GGATAAGCGTG GTCCTGAG TCGCGCCACCGAAGCGAGCAAAACCCTGCAGGAGGTTCTGAGCGTGCTACATAACGATGCCTTTATGCAGCA- CGGGATGATTTG CCTGTACG ACAGCCAGCAGGAGATCCTGAGCATCGAAGCGCTGCAGCAAACGGAAGATCAGACGCTGCCCGGCAGTACGC- AAATTCGCTACC GGCCGGGG GAAGGATTAGTCGGTACCGTGCTGGCGCAGGGCCAGTCGCTGGTGCTGCCGCGCGTCGCCGACGACCAGCGT- TTTCTCGATCGT CTGAGCCT GTACGACTATGACCTGCCGTTTATCGCCGTTCCGCTGATGGGCCCCCACTCCCGGCCCATCGGCGTACTGGC- GGCGCAGCCGAT GGCGCGTC AGGAAGAGCGGCTGCCCGCCTGCACGCGCTTTCTCGAAACCGTCGCCAATCTGATCGCCCAGACGATTCGCC- TGATGATCCTGC CAACCTCC GCCGCGCAGGCGCCGCAGCAGAGCCCCAGAATAGAGCGCCCGCGCGCCTGTACCCCTTCGCGCGGTTTCGGC- CTGGAAAATATG GTCGGTAA AAGCCCGGCGATGCGGCAGATTATGGATATTATTCGTCAGGTTTCCCGCTGGGATACCACGGTGCTGGTACG- CGGCGAGAGCGG CACCGGGA AAGAGCTCATCGCCAACGCCATCCACCATAATTCTCCGCGCGCCGCCGCGGCGTTCGTCAAATTTAACTGCG- CGGCGCTGCCGG ACAACCTG CTGGAGAGCGAGCTGTTTGGTCATGAGAAAGGCGCGTTTACCGGCGCGGTGCGCCAGCGGAAAGGCCGCTTT- GAGCTGGCGGAC GGCGGCAC CTTATTCCTCGATGAGATCGGCGAAAGCAGCGCCTCGTTTCAGGCTAAGCTACTGCGTATTCTGCAAGAGGG- GGAGATGGAGCG CGTCGGCG GCGACGAAACCCTGCGGGTCAACGTGCGCATTATCGCGGCGACCAACCGCCATCTGGAAGAGGAGGTGCGGC- TGGGTCATTTCC GCGAGGAT CTATACTACCGCCTGAACGTAATGCCTATCGCGCTGCCGCCGCTGCGCGAGCGCCAGGAGGATATCGCCGAG- CTGGCGCACTTT CTGGTGCG AAAAATCGCCCACAGCCAGGGGCGAACGCTGCGCATCAGCGATGGGGCGATTCGCCTGCTGATGGAGTACAG- CTGGCCGGGAAA CGTGCGCG AACTGGAAAACTGTCTCGAACGTTCGGCGGTGCTGTCGGAAAGCGGCCTGATAGACCGGGACGTGATTCTGT- TCAACCATCGCG ATAACCCG CCGAAAGCGCTCGCCAGCAGCGGCCCGGCGGAGGACGGCTGGCTCGATAACAGCCTCGACGAGCGCCAGCGG- CTGATCGCCGCC CTGGAAAA AGCGGGCTGGGTGCAGGCCAAAGCGGCGCGGCTGCTCGGCATGACCCCGCGCCAGGTGGCGTATCGCATTCA- GATTATGGATAT CACCATGC CGCGACTGTGA nifA of P. stutzeri Gene ATGAACGCCACATTCGCCGAACGCCCCAGCGCGCCAACCCGCAACGAACTGCTGGATGCCCAACTGCAGGCGC- TGGCGCAGATC GCCCGCAT CCTTAACCGCGGCCGGCCCATCGAGGAACTGCTGGCCGAGATCCTCGCCGTGCTGCACGAAGACCTCGGCCT- GCTGCACGGGCT GGTCTCCA TCTGCAACCCGAAGGACGGCAGCCTGCAGGTGGGCGCCGTGCACAGCGACTCCGAAACCGTGGTACGGGCCT- GCGAAAGCACCC GCTACCGC ATCGGCGAAGGCGTGTTCGGCAACATCCTCAAGCATGGCAACAGCGTGGTGCTCGGGCGTATCGACGCCGAA- CCGCGCTTTCTC GACCGACT GGCGCTGTACGACATGGACCTGCCCTTCATCGCCGTGCCGATCAAGGCCGTCGACGGCACCACCATCGGCGT- GCTGGCTGCCCA GCCCGACC GCCGCGCCGACGAGCTGATGCCCGAACGCACCCGTTTGATGGAAATCGTCGCCCGCCTACTGGCGCAGACCG- TGCGCCTGGTGG TGAACCTC GAGGACGGCCAGGAAGTGGTCGACGAGCGCGACGAGCTACGCCGCGAAGTCCGCGCCAAGTACGGCTTCGAG- AACATGGTGGTG GGCCACAC CGCCTCCATGCGCCGGGTTTTCGACCAGGTTCGACGGGTCGCCAAGTGGAACAGCACCGTGCTGATCCTCGG- CGAATCCGGCAC CGGCAAGG AGCTGATCGCCAGCGCCATCCACTACAACTCACCGCGCGCTCACCAGCCGCTGGTACGCCTGAACTGCGCCG- CGCTACCGGAAA CCCTGCTC GAATCGGAACTGTTCGGTCACGAGAAAGGCGCCTTCACCGGCGCCGTGAAGCAGCGCAAGGGACGTTTCGAA- CAGGCCGACGGC GGCACCCT GTTCCTCGACGAGATCGGCGAGATCTCGCCGATGTTCCAGGCCAAGCTGCTGCGCGTGCTGCAGGAAGGCGA- GCTGGAGCGCGT CGGCGGCA GCCAGACGGTGAAGGTCAACGTGCGCATCGTCGCCGCCACCAACCGCGACCTGGAGCACGAGGTGGAGCAAG- GCAAGTTCCGCG AAGACCTC TACTACCGCCTCAACGTCATGGCCATCCGCGTCCCGCCGCTGCGCGAGCGCAGCGCCGACATCCCGGAACTG- GCCGAATTCCTC CTCGACAA GATCGCCCGCCAGCAGGGTCGCAAACTCAAGCTGACCGACAGCGCCCTGCGTCTGCTGATGAGCCACCGCTG- GCCGGGCAACGT GCGCGAAC TGGAAAACTGCCTGGAACGCTCGGCCATCATGAGCGAGGATGGCACCATCAGCCGCGACGTGGTCTCCCTCA- CCGGCCTCGACC ACGACGCC ACGCCGCTGGCGCCGGTCCCCGAAGTCGACCTCGCCGACGACAGCCTCGACGACCGCGAGCGCGTCATCGCC- GCGCTGGAACAG GCCGGCTG GGTCCAGGCCAAGGCCGCCCGCCTGCTCGGCATGACGCCCCGGCAGATCGCCTACCGAGTGCAGACGCTGAA- CATTCATATGCG CAAGATCT GA nifA of A. vinelandii Gene ATGAATGCAACCATCCCTCAGCGCTCGGCCAAACAGAACCCGGTCGAACTCTATGACCTGCAATTGCAGGCCC- TGGCGAGCATC GCCCGCAC GCTCAGCCGCGAACAACAGATCGACGAACTGCTCGAACAGGTCCTGGCCGTACTGCACAATGACCTCGGCCT- GCTGCATGGCCT GGTGACCA TTTCCGACCCGGAACACGGCGCCCTGCAGATCGGCGCCATCCACACCGACTCGGAAGCGGTGGCCCAGGCCT- GCGAAGGCGTGC GCTACAGA AGCGGCGAAGGCGTGATCGGCAACGTGCTCAAGCACGGCAACAGCGTGGTGCTCGGGCGCATCTCCGCCGAC- CCGCGCTTTCTC GACCGCCT GGCGCTGTACGACCTGGAAATGCCGTTCATCGCCGTGCCGATCAAGAACCCCGAGGGCAACACCATCGGCGT- GCTGGCGGCCCA GCCGGACT GCCGCGCCGACGAGCACATGCCCGCGCGCACGCGCCTTCTGGAGATCGTCGCCAACCTGCTGGCGCAGACCG- TGCGCCTGGTGG TGAACATC GAGGACGGCCGCGAGGCGGCCGACGAGCGCGACGAACTGCGTCGCGAGGTGCGCGGCAAGTACGGCTTCGAG- AACATGGTGGTG GGCCACAC CCCCACCATGCGCCGGGTGTTCGATCAGATCCGCCGGGTCGCCAAGTGGAACAGCACCGTACTGGTCCTCGG- CGAGTCCGGTAC CGGCAAGG AACTGATCGCCAGCGCCATCCACTACAACTCGCCGCGCGCGCACCGCCCCTTCGTGCGCCTGAACTGCGCCG- CGCTGCCGGAAA CCCTGCTC GAGTCCGAACTCTTCGGCCACGAGAAGGGCGCCTTCACCGGCGCGGTGAAGCAGCGCAAGGGGCGTTTCGAG- CAGGCCGACGGC GGCACCCT GTTCCTCGACGAGATCGGCGAGATCTCGCCGATGTTCCAGGCCAAGCTGCTGCGCGTGCTGCAGGAAGGCGA- GTTCGAGCGGGT CGGCGGCA ACCAGACGGTGCGGGTCAACGTGCGCATCGTCGCCGCCACCAACCGCGACCTGGAAAGCGAGGTGGAAAAGG- GCAAGTTCCGCG AGGACCTC TACTACCGCCTGAACGTCATGGCCATCCGCATTCCGCCGCTGCGCGAGCGTACCGCCGACATTCCCGAACTG- GCGGAATTCCTG CTCGGCAA GATCGGCCGCCAGCAGGGCCGCCCGCTGACCGTCACCGACAGCGCCATCCGCCTGCTGATGAGCCACCGCTG- GCCGGGCAACGT GCGCGAAC TGGAGAACTGCCTGGAGCGCTCGGCGATCATGAGCGAGGACGGCACCATCACCCGCGACGTGGTCTCGCTGA- CCGGGGTCGACA ACGAGAGC CCGCCGCTCGCCGCGCCGCTGCCCGAGGTCAACCTGGCCGACGAGACCCTGGACGACCGCGAACGGGTGATC- GCCGCCCTCGAA CAGGCCGG CTGGGTGCAGGCCAAGGCCGCGCGGCTGCTGGGCATGACGCCGCGGCAGATCGCCTACCGCATCCAGACCCT- CAACATCCACAT GCGCAAGA TCTGA nifA of R. sp. Gene ATGCTGCACAATGGGCTCAATGAGGGTATGACTGAACGATCCGCTCAAACCATCCACAAACCGGATTTCTGGG- GCAGCGGTATC IRBG74 TATCGGAT ATCGAAAGTTTTGATTGGTCCAGACAGTCTCGAGACGAAGCTTGCCAATGTCATTAACGCCCTCTCAGTAAT- TCTCCCAATGCG GCGCGGCG CAATCGTCGTTCTAAATGTTAAAGGAGAGCCCGAGATGGTTGCAATGCTGGGCCTAGAGCAAGCATCTCAAG- GCGCCCGCTCCA TTCCGGCG GAGGCTGCGATAGATAGAATCGTCGCCAAAGGCGCGCCGCTGGTCGTACCGGACATTTGCAAGTCGGACCTG- TTCCAGGCGGAG CTCCAAAC CAACTCGAACGCCACAGGCCCAGCCACGTTCGTTGGCGTCCCGATGAAGGTCGAAAAAGAAACGCTTGGAAC- ACTATGGATCGA CCGCGCCA AAGATGGCAGCACTAGGATCCAATTTGAGGAAGAGGTGCGCTTCCTCTCCATGGTCGCCAACCTTTCGGCCC-

GGGCCATTTGGC TGGATCGC CACCAGAGCCGCGATGGTCAGCCAATCGTGGGCGAGGAAGGAACTCGCAAGACTAGTTCAGGCGACAAGGAA- CTGCCCGAATCT GCCCGACA AAGGCCCACAAAAATCGATTGGATTGTCGGGGAAAGCCCTGCCCTCAAGCAGGTGGTTGAAAGCGTCAAAGT- CGTTGCAACAAC CAATTCTG CGGTGCTTCTCAGGGGCGAAAGCGGCACGGGCAAGGAGTTCTTTGCAAAGGCCATCCACGAGCTTTCATACC- GGAAAAAGAAGC CCTTCGTG AAGTTGAACTGCGCCGCGCTGTCTGCAGGCGTTTTGGAATCGGAATTGTTTGGACATGAAAAGGGCGCCTTC- ACGGGGGCCATC TCTCAGCG CGCAGGCCGCTTCGAACTCGCAGACGGCGGAACGCTGCTGCTCGATGAGATCGGCGACATTTCGCCGGGCTT- CCAAGCGAAACT GTTGCGCG TCTTGCAGGAAGGTGAGCTTGAGCGAGTCGGCGGCACAAAAACACTCAAAGTGGACGTTCGACTCATATGCG- CCACGAACAAAG ACCTAGAA GCGGCAGTCGCGGATGGGGAGTTCAGGGCCGACCTTTATTACCGGATCAATGTGGTGCCCCTATTTCTGCCG- CCTCTCCGGGAG CGAAATGG GGATATTCCACGCCTTGCGAGAGTTTTCCTCGGCCGATTCAACAGGGAAAACAATCGCGATCTCGCGTTCGC- GCCGGCTGCGCT CGAGCTCT TGTCAAAATGCAACTTTCCCGGCAACGTCCGAGAGCTTGAAAACTGCGTCCGCAGGACCGCCACTCTCGCGC- GTTCGGAGACGA TCGTTCCA TCAGATTTCTCCTGCCTGAAGAACCAGTGCTTTTCTTCAATGCTCTGGAAAACCGGTGACCGTCCACTTGGG- GATACGCTCAAT GGGTTGGC CATGCGTAAGAGTTTGTCGGTCGAATCGCCGATCAGCCTCGGTTACTCCAATGGACCGGCCGGCTTAACGGT- GGCACCACATCT AACGGACC GCGAGCTGCTAATCAGTGCGATGGAGAAGGCCGGTTGGGTTCAGGCAAAGGCAGCTCGGATCCTCGGCCTCA- CACCGCGACAGG TCGGCTAT GCTTTACGTAGGCATCGTATACAGGTGAAGAAAATCTAA nifA of A. caulinodans Gene ATGCCAATGACCGACGCCTTCCAGGTCCGCGTACCTCGGGTTTCGTCGAGCACCGCCGGAGACATCGCCGCGT- CATCCATCACC ACGCGGGG CGCGCTGCCGCGCCCGGGAGGGATGCCTGTGTCCATGTCGCGGGGGACCTCGCCCGAGGTGGCACTCATCGG- GGTCTATGAGAT ATCGAAGA TCCTGACGGCGCCCCGGCGCCTCGAAGTCACGCTCGCCAATGTGGTGAACGTGCTCTCCTCCATGCTGCAGA- TGCGGCATGGCA TGATCTGC ATCCTCGACAGCGAGGGCGATCCCGACATGGTGGCCACCACCGGCTGGACGCCTGAGATGGCGGGCCAGATC- CGCGCGCATGTG CCCCAGAA GGCCATCGACCAGATCGTCGCCACGCAGATGCCGCTGGTGGTGCAGGACGTGACGGCCGATCCGCTCTTCGC- CGGTCACGAGGA TCTGTTCG GCCCGCCTGAGGAGGCCACCGTCTCCTTCATCGGCGTGCCGATCAAGGCCGACCACCATGTGATGGGCACCC- TCTCCATCGACC GCATCTGG GACGGCACCGCCCGTTTCCGCTTCGACGAGGACGTGCGCTTCCTCACCATGGTGGCCAATCTCGTCGGCCAG- ACCGTGCGCCTG CACAAGCT GGTGGCGAGCGACCGCGACCGGCTGATCGCCCAGACGCACCGCCTCGAAAAGGCGCTGCGGGAAGAAAAATC- CGGGGCCGAGCC GGAGGTGG CCGAGGCCGCCAACGGATCCGCCATGGGCATCGTGGGCGATAGCCCGCTGGTGAAACGCCTGATCGCGACCG- CGCAAGTGGTCG CCCGCTCA AACTCCACCGTGCTGCTGCGCGGGGAGAGCGGCACCGGCAAGGAGTTGTTCGCCCGTGCCATCCACGAACTG- TCGCCCCGCAAG GGCAAGCC CTTCGTGAAGGTGAACTGCGCCGCCCTCCCGGAATCGGTGCTGGAATCGGAACTGTTCGGCCATGAGAAGGG- CGCCTTCACCGG TGCGCTGA ACATGCGCCAGGGCCGCTTCGAGCTGGCGCACGGCGGCACGCTCTTCCTTGACGAGATCGGCGAGATCACCC- CCGCTTTCCAGG CCAAGCTG CTGCGCGTGCTGCAGGAAGGCGAGTTCGAGCGGGTCGGCGGCAATCGCACGCTGAAGGTGGATGTGCGGCTC- GTGTGCGCCACC AACAAGAA TCTGGAAGAGGCGGTCTCCAAGGGCGAGTTCCGGGCCGATCTCTACTACCGCATCCATGTGGTGCCGCTGAT- CCTGCCGCCGCT GCGCGAAC GGCCGGGCGACATTCCCAAGCTCGCGAAGAACTTCCTCGACCGCTTCAACAAGGAAAACAAGCTCCACATGA- TGCTCTCGGCGC CGGCCATC GACGTGCTGCGGCGCTGCTATTTCCCGGGCAACGTGCGCGAGCTGGAGAACTGTATCCGGCGGACGGCAACG- CTCGCCCACGAT GCCGTCAT CACCCCCCATGACTTCGCCTGCGACAGCGGCCAGTGCCTCTCGGCCATGCTCTGGAAGGGCTCGGCCCCGAA- GCCTGTGATGCC GCACGTGC CGCCGGCGCCCACGCCGCTGACTCCGCTCTCCCCTGCTCCGCTCGCGACCGCAGCGCCCGCTGCGGCGAGCC- CGGCGCCGGCGG CCGACAGC CTGCCGGTCACTTGCCCCGGCACCGAGGCCTGTCCCGCGGTGCCCCCCCGCCAGAGCGAAAAGGAGCAGTTG- CTCCAGGCCATG GAGCGCTC CGGCTGGGTGCAGGCGAAGGCCGCGCGCCTCCTCAACCTCACGCCGCGCCAGGTGGGTTATGCGCTGCGCAA- ATATGACATCGA CATCAAGC GCTTCTGA P.sub.J3123100 Promoter.sup.9 TAGGTGTTGACGGCTAGCTCAGTCCTAGGTACAGTGCTAGCTCTAGA P.sub.J3123101 Promoter.sup.9 TAGGTGTTTACAGCTAGCTCAGTCCTAGGTATTATGCTAGCTCTAGA P.sub.J3123102 Promoter.sup.9 TAGGTGTTGACAGCTAGCTCAGTCCTAGGTACTGTGCTAGCTCTAGA P.sub.J3123103 Promoter.sup.9 TAGGTGCTGATAGCTAGCTCAGTCCTAGGGATTATGCTAGCTCTAGA P.sub.J23104 Promoter.sup.9 TAGGTGTTGACAGCTAGCTCAGTCCTAGGTATTGTGCTAGCTCTAGA P.sub.J23105 Promoter.sup.9 TAGGTGTTTACGGCTAGCTCAGTCCTAGGTACTATGCTAGCTCTAGA P.sub.J23106 Promoter.sup.9 TAGGTGTTTACGGCTAGCTCAGTCCTAGGTATAGTGCTAGCTCTAGA P.sub.J23107 Promoter.sup.9 TAGGTGTTTACGGCTAGCTCAGCCCTAGGTATTATGCTAGCTCTAGA P.sub.J23108 Promoter.sup.9 TAGGTGCTGACAGCTAGCTCAGTCCTAGGTATAATGCTAGCTCTAGA P.sub.J23109 Promoter.sup.9 TAGGTGTTTACAGCTAGCTCAGTCCTAGGGACTGTGCTAGCTCTAGA P.sub.J23110 Promoter.sup.9 TAGGTGTTTACGGCTAGCTCAGTCCTAGGTACAATGCTAGCTCTAGA P.sub.J23111 Promoter.sup.9 TAGGTGTTGACGGCTAGCTCAGTCCTAGGTATAGTGCTAGCTCTAGA P.sub.J23112 Promoter.sup.9 TAGGTGCTGATAGCTAGCTCAGTCCTAGGGATTATGCTAGCTCTAGA P.sub.J23113 Promoter.sup.9 TAGGTGCTGATGGCTAGCTCAGTCCTAGGGATTATGCTAGCTCTAGA P.sub.J23114 Promoter.sup.9 TAGGTGTTTATGGCTAGCTCAGTCCTAGGTACAATGCTAGCTCTAGA P.sub.J23115 Promoter.sup.9 TAGGTGTTTATAGCTAGCTCAGCCCTTGGTACAATGCTAGCTCTAGA P.sub.J23116 Promoter.sup.9 TAGGTGTTGACAGCTAGCTCAGTCCTAGGGACTATGCTAGCTCTAGA P.sub.J23117 Promoter.sup.9 TAGGTGTTGACAGCTAGCTCAGTCCTAGGGATTGTGCTAGCTCTAGA P.sub.J23118 Promoter.sup.9 TAGGTGTTGACGGCTAGCTCAGTCCTAGGTATTGTGCTAGCTCTAGA P.sub.J23119 Promoter.sup.9 TAGGTGTTGACAGCTAGCTCAGTCCTAGGTATAATGCTAGCTCTAGA P.sub.trp Promoter.sup.10 TAGGTGTTGACATTATTCCATCGAACTAGTTAACTAGTACGAAAGTT T.sub.T7 Terminator.sup.11 TAGCATAACCCCTTGGGGCCTCTAAACGGGTCTTGAGGGGTTTTTTGT T.sub.T2.2 Terminator.sup.11 TACTCGAACCCCTAGCCCGCTCTTATCGGGCGGCTAGGGGTTTTTTGT T.sub.T7.3 Terminator.sup.11 TACATATCGGGGGGGTAGGGGTTTTTTGT T.sub.rrnBT1 Terminator.sup.12 CCAGGCATCAAATAAAACGAAAGGCTCAGTCGAAAGACTGGGCCTTTCGTTTTATCTGTTGTTTGTCGGTGAA- CGCTCTC T.sub.L3S2P21 Terminator.sup.13 CTCGGTACCAAATTCCAGAAAAGAGGCCTCCCGAAAGGGGGGCCTTTTTTCGTTTTGGTCC T.sub.1 Terminator.sup.13 CTCGGTACCAAATTCCAGAAAAGACACCCGAAAGGGTGTTTTTTCGTTTTGGTCCTCCTTGGCCCTCCATCCT- TAGATAGCAGA TAAAAAAA ATCCTTAGCTTTCGCTAAGGATGATTTCTTCATAGGCAATACGATCGCATGTCC T.sub.2 Terminator.sup.14 CCAGGCATCAAATAAAACGAAAGGCTCAGTCGAAAGACTGGGCCTTTCGTTTTATCTGTTGTTTGTCGGTGAA- CGCTCTCTACT AGAGTCAC ACTGGCTCACCTTCGGGTGGGCCTTTCTGCGTTTATA T.sub.3 Terminator.sup.13 CCAGGCATCAAATAAAACGAAAGGCTCAGTCGAAAGACTGGGCCTTTCGTTTTATCTGTTGTTTGTCGGTGAA- CGCTCTCTACT AGAGTCAC ACTGGCTCACCTTCGGGTGGGCCTTTCTGCGTTTATA T.sub.4 Terminator.sup.13 GGTCTTGTCCACTACCTTGCAGTAATGCGGTGGACAGGATCGGCGGTTTTCTTTTCTCTTCTCAATGACTGAA- TAGAAAAGACG AACATTAA CGCATGAGAAAGCCCCCGGAAGATCACCTTCCGGGGGCTTTTTTATTGCGCTACAAATGAAAGTACATAGAA- ATTA T.sub.5 Terminator.sup.13 CAGATAAAAAAAATCCTTAGCTTTCGCTAAGGATGATTTCTTCCTTGGCCCTCCATCCTTAGATAGCTCGGTA- CCAAATTCCAG AAAAGACA CCCGAAAGGGTGTTTTTTCGTTTTGGTCCTCATAGGCAATACGATCGCATGTCC T.sub.6 Terminator.sup.13 CCAGGCATCAAATAAAACGAAAGGCTCAGTCGAAAGACTGGGCCTTTCGTTTTATCTGTTGTTTGTCGGTGAA- CGCTCTCCTAG CATAACCC CTTGGGGCCTCTAAACGGGTCTTGAGGGGTTTTTTG T.sub.7 Terminator.sup.13 CTCGGTACCAAATTCCAGAAAAGAGACGCTTTCGAGCGTCTTTTTTCGTTTTGGTCCTCCTTGGCCCTCCATC- CTTAGATAGAG TTAACCAA AAAGGGGGGATTTTATCTCCCCTTTAATTTTTCCTTCATAGGCAATACGATCGCATGTCC T.sub.8 Terminator.sup.13 CGCAGATAGCAAAAAAGCGCCTTTAGGGCGCTTTTTTACATTGGTGGTCCTTGGCCCTCCATCCTTAGATAGA- GGCGACTGACG AAACCTCG CTCCGGCGGGGTTTTTTGTTATCTGCATCATAGGCAATACGATCGCATGTCC T.sub.9 Terminator.sup.14 TCGGTCAGTTTCACCTGATTTACGTAAAAACCCGCTTCGGCGGGTTTTTGCTTTTGGAGGGGCAGAAAGATGA- ATGACTG TC T.sub.10 Terminator.sup.14 GCCCCCGGAAGATCACCTTCCGGGGGCTTTTTTATTGGCGGCCGGCTGATTGATCAGGCGGCCGGCTGATTGG- CGCGTTACCTG GTAGCGCG CCATTTTGTTT T.sub.11 Terminator.sup.14 GTAATCGTTAATCCGCAAATAACGTAAAAACCCGCTTCGGCGGGTTTTTTTATGGGGGGAGTTTAGGGAAAGA- GCATTTG TCA T.sub.12 Terminator.sup.14 AAAAAAAAACCCCGCCCCTGACAGGGCGGGGTTTTTTTTTT T.sub.13 Terminator.sup.13 TCCGGCAATTAAAAAAGCGGCTAACCACGCCGCTTTTTTTACGTCTGCATGACTGAATAGAAAAGACGAACAT- TAACGCATGAG AAAGCCCC CGGAAGATCACCTTCCGGGGGCTTTTTTATTGCGCTCCTTGGCCCTCCATCCTTAGATAG T.sub.14 Terminator.sup.13 GGAAGACCATACTGGAAACACAGAAAAAAGCCCGCACCTGACAGTGCGGGCTTTTTTTTTCGACCAAAGGTGA- CTGAATAGAAA AGACGAAC ATTCGCAGATAGCAAAAAAGCGCCTTTAGGGCGCTTTTTTACATTGGTGGTCATAGGCAATACGATCGCATG- TCC T.sub.15 Terminator.sup.13 TCCGGCAATTAAAAAAGCGGCTAACCACGCCGCTTTTTTTACGTCTGCATCCTTGGCCCTCCATCCTTAGATA-

GCTCGGTACCA AATTCCAG AAAAGAGGCCTCCCGAAAGGGGGGCCTTTTTTCGTTTTGGTCCTCATAGGCAATACGATCGCA- TGTCC T.sub.16 Terminator.sup.13 TTCAGCCAAAAAACTTAAGACCGCCGGTCTTGTCCACTACCTTGCAGTAATGCGGTGGACAGGATCGGCGGTT- TTCTTTTCTCT TCTCAATA CATGAAAGTACATAGAAATTACTCGGTACCAAATTCCAGAAAAGAGGCCTCCCGAAAGGGGGGCCTTTTTTC- GTTTTGGTCCTC ATAGGCAA TACGATCGCATGTCC T.sub.17 Terminator.sup.13 TTCAGCCAAAAAACTTAAGACCGCCGGTCTTGTCCACTACCTTGCAGTAATGCGGTGGACAGGATCGGCGGTT- TTCTTTTCTCT TCTCAATC CTTGGCCCTCCATCCTTAGATAGTCCGGCAATTAAAAAAGCGGCTAACCACGCCGCTTTTTTTACGTCTGCA- TCATAGGCAATA CGATCGCA TGTCC T.sub.18 Terminator.sup.13 CTCGGTACCAAATTCCAGAAAAGAGGCCTCCCGAAAGGGGGGCCTTTTTTCGTTTTGGTCCTGACTGAATAGA- AAAGACGAACA TTAACGCA TGAGAAAGCCCCCGGAAGATCACCTTCCGGGGGCTTTTTTATTGCGCTCCTTGGCCCTCCATCCTTAGATAG T.sub.19 Terminator.sup.13 CTCGGTACCAAATTCCAGAAAAGAGGCCTCCCGAAAGGGGGGCCTTTTTTCGTTTTGGTCCTCCTTGGCCCTC- CATCCTTAGAT GTCCGGCA ATTAAAAAAGCGGCTAACCACGCCGCTTTTTTTACGTCTGCATCATAGGCAATACGATCGCAT- GTCC T.sub.20 Terminator.sup.13 CTCGGTACCAAAGACGAACAATAAGACGCTGAAAAGCGTCTTTTTTCGTTTTGGTCCTACAAATGAAAGTACA- TAGAAATTATT CAGCCAAA AAACTTAAGACCGCCGGTCTTGTCCACTACCTTGCAGTAATGCGGTGGACAGGATCGGCGGTTTTCTTTTCT- CTTCTCAATCCT TGGCCCTC CATCCTTAGATAG T.sub.21 Terminator.sup.14 GGGAACTGCCAGACATCAAATAAAACAAAAGGCTCAGTCGGAAGACTGGGCCTTTTGTTTTATCTGTTGTTTG- TCGGTGAACAC TCTCCCGA CTAGTAGCGGCCGCTGCAGAAAGAGGAGA T.sub.22 Terminator.sup.13 AACGCATGAGAAAGCCCCCGGAAGATCACCTTCCGGGGGCTTTTTTATTGCGCTCATAGGCAATACGATCGCA- TGTCCTCCGGC AATTAAAA AAGCGGCTAACCACGCCGCTTTTTTTACGTCTGCATCCTTGGCCCTCCATCCTTAGATAG T.sub.23 Terminator.sup.14 GGGAACTGCCAGACATCAAATAAAACAAAAGGCTCAGTCGGAAGACTGGGCCTTTTGTTTTATCTGTTGTTTG- TCGGTGA ACACTCTCCCG T.sub.24 Terminator.sup.14 AAAGCAAGCTGATAAACCGATACAATTAAAGGCTCCTTTTGGAGCCTTTTTTTTTGGAGATTTTCAACATGAA- AAAATTATTAT TTGATGAT CAGATAGCGGCGGGGAACTGCCAGACATCAAATAAAACAAAAGGCTCAGTCGGAAGACTGGGCCTTTTGTTT- TATCTGTTGTTT GTCGGTGA ACACTCTCCCG T.sub.25 Terminator.sup.13 AACGCATGAGAAAGCCCCCGGAAGATCACCTTCCGGGGGCTTTTTTATTGCGCTCCTTGGCCCTCCATCCTTA- GATAGCTCGGT ACCAAATT CCAGAAAAGAGGCCTCCCGAAAGGGGGGCCTTTTTTCGTTTTGGTCCTCATAGGCAATACGATCGCATGTCC T.sub.26 Terminator.sup.14 AACGCATGAGAAAGCCCCCGGAAGATCACCTTCCGGGGGCTTTTTTATTGCGCTCCTTGGCCCTCCATCCTTA- GATAGTTCAGC CAAAAAAC TTAAGACCGCCGGTCTTGTCCACTACCTTGCAGTAATGCGGTGGACAGGATCGGCGGTTTTCTTTTCTCTTC- TCAATCATAGGC AATACGAT CGCATGTCC P.sub.Lux Promoter.sup.15 CCTAGGACCTGTAGGATCGTACAGGTTTACGCAAGAAAATGGTTTGTTACTTTCGAATAAATCTAGA P.sub.Tet Promoter.sup.16 CGGTGGAATCCCTATCAGTGATAGAGATTGACATCCCTATCAGTGATAGATATAATGAGCACTCTAGA P.sub.Cym Promoter.sup.5 AACAAACAGACAATCTGGTCTGTTTGTATTATGGAAAATTTTTCTGTATAATAGATTCAACAAACAGACAATC- TGGTCTG TTTGTATTAT P.sub.Phl Promoter.sup.17 AAAAAGAGTTTGACATGATACGAAACGTACCGTATCGTTAAGGTTACTAGAGTCTAGA P.sub.Sal Promoter.sup.5 GGGGCCTCGCTTGGGTTATTGCTGGTGCCCGGCCGGGCGCAATATTCATGTTGATGATTTATTATATATCGAG- TGGTGTATTTA TTTATATT GTTTGCTCCGTTACCGTTATTAAC luxR Gene ATGAAAAACATAAATGCCGACGACACATACAGAATAATTAATAAAATTAAAGCTTGTAGAAGCA- ATAATGATATTAATCAATGC TTATCTGA TATGACTAAAATGGTACATTGTGAATATTATTTACTCGCGATCATTTATCCTCATTCTATGGTTAAATCTGA- TATTTCAATCCT AGATAATT ACCCTAAAAAATGGAGGCAATATTATGATGACGCTAATTTAATAAAATATGATCCTATAGTAGATTATTCTA- ACTCCAATCATT CACCAATT AATTGGAATATATTTGAAAACAATGCTGTAAATAAAAAATCTCCAAATGTAATTAAAGAAGCGAAAACATCA- GGTCTTATCACT GGGTTTAG TTTCCCTATTCATACGGCTAACAATGGCTTCGGAATGCTTAGTTTTGCACATTCAGAAAAAGACAACTATAT- AGATAGTTTATT TTTACATG CGTGTATGAACATACCATTAATTGTTCCTTCTCTAGTTGATAATTATCGAAAAATAAATATAGCAAATAATA- AATCAAACAACG ATTTAACC AAAAGAGAAAAAGAATGTTTAGCGTGGGCATGCGAAGGAAAAAGCTCTTGGGATATTTCAAAAATATTAGGT- TGCAGTGAGCGT ACTGTCAC TTTCCATTTAACCAATGCGCAAATGAAACTCAATACAACAAACCGCTGCCAAAGTATTTCTAAAGCAATTTT- AACAGGAGCAAT TGATTGCC CATACTTTAAAAATTAA tetR Gene ATGTCCAGATTAGATAAAAGTAAAGTGATTAACAGCGCATTAGAGCTGCTTAATGAGGTCGGAA- TCGAAGGTTTAACAACCCGT AAACTCGC CCAGAAGCTAGGTGTAGAGCAGCCTACATTGTATTGGCATGTAAAAAATAAGCGGGCTTTGCTCGACGCCTT- AGCCATTGAGAT GTTAGATA GGCACCATACTCACTTTTGCCCTTTAGAAGGGGAAAGCTGGCAAGATTTTTTACGTAATAACGCTAAAAGTT- TTAGATGTGCTT TACTAAGT CATCGCGATGGAGCAAAAGTACATTTAGGTACACGGCCTACAGAAAAACAGTATGAAACTCTCGAAAATCAA- TTAGCCTTTTTA TGCCAACA AGGTTTTTCACTAGAGAATGCATTATATGCACTCAGCGCTGTGGGGCATTTTACTTTAGGTTGCGTATTGGA- AGATCAAGAGCA TCAAGTCG CTAAAGAAGAAAGGGAAACACCTACTACTGATAGTATGCCGCCATTATTACGACAAGCTATCGAATTATTTG- ATCACCAAGGTG CAGAGCCA GCCTTCTTATTCGGCCTTGAATTGATCATATGCGGATTAGAAAAACAACTTAAATGTGAAAGTGGGTCCTAA cymR Gene ATGAGCCCGAAACGTCGTACCCAGGCAGAACGTGCAATGGAAACCCAGGGTAAACTGATTGCAG- CAGCACTGGGTGTTCTGCGT GAAAAAGG TTATGCAGGTTTTCGTATTGCAGATGTTCCGGGTGCAGCCGGTGTTAGCCGTGGTGCACAGAGCCATCATTT- TCCGACCAAACT GGAACTGC TGCTGGCAACCTTTGAATGGCTGTATGAGCAGATTACCGAACGTAGCCGTGCACGTCTGGCAAAACTGAAAC- CGGAAGATGATG TTATTCAG CAGATGCTGGATGATGCAGCAGAATTTTTTCTGGATGATGATTTTAGCATCAGCCTGGATCTGATTGTTGCA- GCAGATCGTGAT CCGGCACT GCGTGAAGGTATTCAGCGTACCGTTGAACGTAATCGTTTTGTTGTTGAAGATATGTGGCTGGGTGTGCTGGT- GAGCCGTGGTCT GAGCCGTG ATGATGCCGAAGATATTCTGTGGCTGATTTTTAACAGCGTTCGTGGTCTGGCAGTTCGTAGCCTGTGGCAGA- AAGATAAAGAAC GTTTTGAA CGTGTGCGTAATAGCACCCTGGAAATTGCACGTGAACGTTATGCAAAATTCAAACGTTGA phlF Gene ATGGCACGTACCCCGAGCCGTAGCAGCATTGGTAGCCTGCGTAGTCCGCATACCCATAAAGCAA- TTCTGACCAGCACCATTGAA ATCCTGAA AGAATGTGGTTATAGCGGTCTGAGCATTGAAAGCGTTGCACGTCGTGCCGGTGCAAGCAAACCGACCATTTA- TCGTTGGTGGAC CAATAAAG CAGCACTGATTGCCGAAGTGTATGAAAATGAAAGCGAACAGGTGCGTAAATTTCCGGATCTGGGTAGCTTTA- AAGCCGATCTGG ATTTTCTG CTGCGTAATCTGTGGAAAGTTTGGCGTGAAACCATTTGTGGTGAAGCATTTCGTTGTGTTATTGCAGAAGCA- CAGCTGGACCCT GCAACCCT GACCCAGCTGAAAGATCAGTTTATGGAACGTCGTCGTGAGATGCCGAAAAAACTGGTTGAAAATGCCATTAG- CAATGGTGAACT GCCGAAAG ATACCAATCGTGAACTGCTGCTGGATATGATTTTTGGTTTTTGTTGGTATCGCCTGCTGACCGAACAGCTGA- CCGTTGAACAGG ATATTGAA GAATTTACCTTCCTGCTGATTAATGGTGTTTGTCCGGGTACACAGCGTTAA nahR Gene ATGGAACTGCGTGACCTGGATTTAAACCTGCTGGTGGTGTTCAACCAGTTGCTGGTCGACAGAC- GCGTCTCTGTCACTGCGGAG AACCTGGG CCTGACCCAGCCTGCCGTGAGCAATGCGCTGAAACGCCTGCGCACCTCGCTACAGGACCCACTCTTCGTGCG- CACACATCAGGG AATGGAAC CCACACCCTATGCCGCGCATCTGGCCGAGCACGTCACTTCGGCCATGCACGCACTGCGCAACGCCCTACAGC- ACCATGAAAGCT TCGATCCG CTGACCAGCGAGCGTACCTTCACCCTGGCCATGACCGACATTGGCGAGATCTACTTCATGCCGCGGCTGATG- GATGCGCTGGCT CACCAGGC CCCCAATTGCGTGATCAGTACGGTGCGCGACAGTTCGATGAGCCTGATGCAGGCCTTGCAGAACGGAACCGT- GGACTTGGCCGT GGGCCTGC TTCCCAATCTGCAAACTGGCTTCTTTCAGCGCCGGCTGCTCCAGAATCACTACGTGTGCCTATGTCGCAAGG- ACCATCCAGTCA CCCGCGAA CCCCTGACTCTGGAGCGCTTCTGTTCCTACGGCCACGTGCGTGTCATCGCCGCTGGCACCGGCCACGGCGAG- GTGGACACGTAC ATGACACG GGTCGGCATCCGGCGCGACATCCGTCTGGAAGTGCCGCACTTCGCCGCCGTTGGCCACATCCTCCAGCGCAC- CGATCTGCTCGC CACTGTGC CGATATGTTTAGCCGACTGCTGCGTAGAGCCCTTCGGCCTAAGCGCCTTGCCGCACCCAGTCGTCTTGCCTG- AAATAGCCATCA ACATGTTC TGGCATGCGAAGTACCACAAGGACCTAGCCAATATTTGGTTGCGGCAACTGATGTTTGACCTGTTTACGGAT- TGATAA P.sub.Fde Promoter.sup.18 TCAATGTATTGATGCCGTCCATATCATGAATCAAAACAATCCATTTGATCAATATCAAGCTCACTCTTAAGCT- TCACTCA TCCGCTGCAT fdeR Gene ATGCGTTTCAACAAGCTCGACCTCAATCTTCTGGTCGCCCTGGATGCACTGCTCACGGAGATGA- GCATCAGCCGCGCCGCCGAA AAGATCCA TCTGAGCCAGTCGGCCATGAGCAATGCCCTGGCGCGGCTGCGCGAGTATTTCGATGATGAATTGCTGATCCA- GGTGGGCCGGCG CATGGAGC CCACGCCGCGCGCCGAGGTGCTCAAGGATGCGGTGCATGATGTGCTGCGGCGTATCGATGGCTCCATCGCGG- CGCTGCCGGCCT TCGTGCCG GCCGAGTCCACGCGCGAGTTTCGCATCTCGGTTTCGGACTTTACGCTCTCCGTCCTCATCCCCCGGGTGCTG- GCGCGCGCGCAC GCCGAGGG CAAGCACATCCGCTTTGCCCTGATGCCGCAGGTGCAAGACCCGACCCGCTCGCTGGATCGGGCCGAGGTGGA- CCTGCTGGTCTT GCCGCAGG AATTCTGCACGCCCGATCATCCTGCCGAAGAGGTCTTCCGCGAACGGCATGTCTGCGTGGTCTGGCGCGACA- GTGCGCTGGCGC AAGGCGAG CTGACGCTGGAACGCTACATGGCCTCAGGCCATGTGGTGATGGTGCCGCCTGGGGCCAATGCGTCGTCGGTG- GAGGCGTGGATG GCCAGGAA GCTGGGCTTTGCGCGCCGGGTGGAAGTGACCAGCTTCAGCTTCGCTTCTGCGCTGGCGCTGGTACAGGGGAC- GGACCGCATCGC CACGGTGC ATGCCCGGCTGGCGCAGCTGCTGGCTCCGCAATGGCCGGTGGTGATCAAGGAGAGTCCGCTGTCGCTGGGCG- AGATGCGGCAGA TGATGCAG TGGCATCGCTACCGCAGCAATGATCCTGGCATCCAGTGGCTGCGTCGGGTGTTTCTGGAGAGTGCGCAGGAG- ATGGATGCGGCG CTGCCAGG CATCTGCTGA P.sub.BAD.10 Promoter CAGACATTGCCGTCACTGCGTCTTTTACTGGCTCTTCTCGCTAACCAAACCGGTAACCCCGCTTATTAAAAGC- ATTCTGTAACA

AAGCGGGA CCAAAGCCATGACAAAAACGCGTAACAAAAGTGTCTATAATCACGGCAGAAAAGTCCACATTGATTATTTGC- ACGGCGTCACAC TTTGCTAT GCCATAGCATTTTTATCCATAAGATTAGCGGATCCTACCTGACGCTTTTTATCGCAACTCTCTATATTTTCT- CCATACCCGTTT TTTTGGGCTAGCGAATTC araC Gene ATGCAATATGGACAATTGGTTTCTTCTCTGAATGGCGGGAGTATGAAAAGTATGGCTGAAGCGC- AAAATGATCCCCTGCTGCCG GGATACTC GTTTAATGCCCATCTGGTGGCGGGTTTAACGCCGATTGAGGCCAACGGTTATCTCGATTTTTTTATCGACCG- ACCGCTGGGAAT GAAAGGTT ATATTCTCAATCTCACCATTCGCGGTCAGGGGGTGGTGAAAAATCAGGGACGAGAATTTGTTTGCCGACCGG- GTGATATTTTGC TGTTCCCG CCAGGAGAGATTCATCACTACGGTCGTCATCCGGAGGCTCGCGAATGGTATCACCAGTGGGTTTACTTTCGT- CCGCGCGCCTAC TGGCATGA ATGGCTTAACTGGCCGTCAATATTTGCCAATACGGGGTTCTTTCGCCCGGATGAAGCGCACCAGCCGCATTT- CAGCGACCTGTT TGGGCAAA TCATTAACGCCGGGCAAGGGGAAGGGCGCTATTCGGAGCTGCTGGCGATAAATCTGCTTGAGCAATTGTTAC- TGCGGCGCATGG AAGCGATT AACGAGTCGCTCCATCCACCGATGGATAATCGGGTACGCGAGGCTTGTCAGTACATCAGCGATCACCTGGCA- GACAGCAATTTT GATATCGC CAGCGTCGCACAGCATGTTTGCTTGTCGCCGTCGCGTCTGTCACATCTTTTCCGCCAGCAGTTAGGGATTAG- CGTCTTAAGCTG GCGCGAGG ACCAACGTATCAGCCAGGCGAAGCTGCTTTTGAGCACCACCCGGATGCCTATCGCCACCGTCGGTCGCAATG- TTGGTTTTGACG ATCAACTC TATTTCTCGCGGGTATTTAAAAAATGCACCGGGGCCAGCCCGAGCGAGTTCCGTGCCGGTTGTGAAGAAAAA- GTGAATGATGTA GCCGTCAA GTTGTCATAA araE Gene ATGGTTACTATCAATACGGAATCTGCTTTAACGCCACGTTCTTTGCGGGATACGCGGCGTATGA- ATATGTTTGTTTCGGTAGCT GCTGCGGT CGCAGGATTGTTATTTGGTCTTGATATCGGCGTAATCGCCGGAGCGTTGCCGTTCATTACCGATCACTTTGT- GCTGACCAGTCG TTTGCAGG AATGGGTGGTTAGTAGCATGATGCTCGGTGCAGCAATTGGTGCGCTGTTTAATGGTTGGCTGTCGTTCCGCC- TGGGGCGTAAAT ACAGCCTG ATGGCGGGGGCCATCCTGTTTGTACTCGGTTCTATAGGGTCCGCTTTTGCGACCAGCGTAGAGATGTTAATC- GCCGCTCGTGTG GTGCTGGG CATTGCTGTCGGGATCGCGTCTTACACCGCTCCTCTGTATCTTTCTGAAATGGCAAGTGAAAACGTTCGCGG- TAAGATGATCAG TATGTACC AGTTGATGGTCACACTCGGCATCGTGCTGGCGTTTTTATCCGATACAGCGTTCAGTTATAGCGGTAACTGGC- GCGCAATGTTGG GGGTTCTT GCTTTACCAGCAGTTCTGCTGATTATTCTGGTAGTCTTCCTGCCAAATAGCCCGCGCTGGCTGGCGGAAAAG- GGGCGTCATATT GAGGCGGA AGAAGTATTGCGTATGCTGCGCGATACGTCGGAAAAAGCGCGAGAAGAACTCAACGAAATTCGTGAAAGCCT- GAAGTTAAAACA GGGCGGTT GGGCACTGTTTAAGATCAACCGTAACGTCCGTCGTGCTGTGTTTCTCGGTATGTTGTTGCAGGCGATGCAGC- AGTTTACCGGTA TGAACATC ATCATGTACTACGCGCCGCGTATCTTCAAAATGGCGGGCTTTACGACCACAGAACAACAGATGATTGCGACT- CTGGTCGTAGGG CTGACCTT TATGTTCGCCACCTTTATTGCGGTGTTTACGGTAGATAAAGCAGGGCGTAAACCGGCTCTGAAAATTGGTTT- CAGCGTGATGGC GTTAGGCA CTCTGGTGCTGGGCTATTGCCTGATGCAGTTTGATAACGGTACGGCTTCCAGTGGCTTGTCCTGGCTCTCTG- TTGGCATGACGA TGATGTGT ATTGCCGGTTATGCGATGAGCGCCGCGCCAGTGGTGTGGATCCTGTGCTCTGAAATTCAGCCGCTGAAATGC- CGCGATTTCGGT ATTACCTG TTCGACCACCACGAACTGGGTGTCGAATATGATTATCGGCGCGACCTTCCTGACACTGCTTGATAGCATTGG- CGCTGCCGGTAC GTTCTGGC TCTACACTGCGCTGAACATTGCGTTTGTGGGCATTACTTTCTGGCTCATTCCGGAAACCAAAAATGTCACGC- TGGAACATATCG AACGCAAA CTGATGGCAGGCGAGAAGTTGAGAAATATCGGCGTCTGA P.sub.tac Promoter.sup.10 CTCGAGTGTTGACAATTAATCATCGGCTCGTATAATGTGTGGAATTGTGAGCGCTCACAATTTCACACATCTA- GA P.sub.noc Promoter AACAAATACACATGGGCGCATGCCTATTACTGCCCTTGCGATATGGAAGGCAAGCTTTTAGTAACAATAGAAA- ACTGGGTCCTA CTCTCGAA GAATGCACTGCGGCGGTCACGTCAACACGTGCTGCACCGTTGAGAATGAATGCTGGGCAGATTGCCAGCGGC- GTCATTTTCGGC TGTCCCGT CCTCACGGTTTTGCGCTGCATCGCAAGAGATTGGGAA nocR Gene ATGACGTCAGCAGCGAATCTGGTGAGGATCACGCAGCCCGCGATCAGCCGGCTGATCAGGGATC- TCGAAGAGGAAATTGGGATC AGCCTCTT CGAAAGAACGGGCAACCGGTTACGTCCTACGCGGGAGGCCGGTATTCTGTTCAAGGAAGTGTCGCGACATTT- CAACGGGATTCA GCACATCG ACAAAGTCGCGGCTGAACTGAAGAAGTCTCATATGGGGTCCCTAAGGGTCGCCTGTTATACAGCGCCAGCTC- TGAGTTTTATGT CCGGCGTC ATTCAGACGTTCATCGCCGATCGGCCCGACGTGTCGGTCTACCTCGACACAGTTCCTTCCCAGACGGTCCTC- GAATTGGTCTCG CTCCAGCA CTACGATCTCGGAATATCGATATTGGCTGGCGACTATCCTGGTCTCACCACCGAACCTGTCCCTTCCTTTCG- TGCGGTCTGCCT GCTGCCGC CGGGGCATCGTCTCGAAGACAAGGAAACTGTTCATGCGACGGACCTTGAAGGAGAGTCATTGATTTGCCTCT- CTCCAGTGAGCC TTCTACGG ATGCAAACGGACGCCGCACTGGACAGCTGCGGCGTCCACTGTAATCGCAGGATAGAAAGTAGTCTGGCGCTG- AATCTCTGCGAT CTGGTAAG CAGGGGAATGGGGGTTGGTATCGTCGACCCCTTCACTGCCGACTACTACAGTGCAAATCCGGTTATTCAGCG- CTCCTTTGATCC GGTTGTCC CCTACCATTTTGCTATAGTTCTTCCGACCGACAGCCCACCGCCGCGCTTGGTTAGCGAGTTCCGGGCAGCGT- TGCTTGATGCTT TGAAAGCC TTGCCCTATGAAACCATTTGA P.sub.occ Promoter AAACGCACCATAACATCTGCTTATTCTTGCCCGGTCATTATGAATTTGACCGAATGCATATCGAATGTAAAGC- TCACCCTATAA ATCACAAC TCTTCCGGGCCAACCGGGATCAGACGT occR Gene ATGAATCTCAGGCAGGTCGAGGCGTTCCGGGCAGTCATGCTGACGGGGCAAATGACGGCGGCGG- CTGAACTAATGCTGGTGACT CAGCCGGC CATCAGTCGCCTAATCAAGGACTTTGAACAGGCGACAAAACTGCAGCTCTTCGAGAGGCGTGGGAACCATAT- TATCCCGACACA GGAGGCAA AGACGCTGTGGAAAGAGGTCGATCGGGCGTTCGTCGGGCTTAATCATATAGGCAACCTGGCTGCCGACATCG- GCAGGCAGGCAG CGGGGACG CTCCGCATTGCTGCAATGCCTGCTCTGGCAAACGGCCTCTTGCCGCGGTTTCTTGCTCAGTTCATCCGTGAC- AGACCAAATCTC CAGGTCTC CCTAATGGGACTGCCCTCAAGCATGGTCATGGAAGCCGTTGCGTCCGGCAGGGCCGACATCGGTTATGCCGA- TGGCCCACAGGA GCGCCAAG GTTTTCTAATCGAAACCCGGTCGCTTCCCGCTGTTGTCGCTGTCCCGATGGGACATCGACTTGCTGGCCTTG- ACCGTGTCACGC CACAGGAC CTTGCCGGTGAGCGTATTATAAAACAGGAGACTGGCACTCTCTTCGCCATGCGGGTAGAGGTGGCGATTGGT- GGTATTCAACGC CGGCCGTC AATTGAAGTGAGCCTGTCGCATACTGCGCTAAGTCTCGTCCGCGAAGGCGCCGGGATCGCAATTATCGATCC- AGCCGCGGCGAT CGAGTTCA CGGACAGGATCGTACTGCGACCGTTCTCGATCTTCATTGACGCCGGATTCCTCGAAGTCCGGTCAGCAATTG- GCGCTCCCTCAA CCATCGTC GATCGTTTCACAACCGAATTCTGGAGGTTTCATGATGACTTGATGAAGCAGAACGGCCTAATG- GAGTAA P.sub.Bet Promoter.sup.17 AGCGCGGGTGAGAGGGATTCGTTACCAATAGACAATTGATTGGACGTTCAATATAATGCTAGC P.sub.Cin Promoter CCCTTTGTGCGTCCAAACGGACGCACGGCGCTCTAAAGCGGGTCGCGATCTTTCAGATTCGCTCCTCGCGCTT- TCAGTCTTTGTTTTGGCGC ATGTCGTTATCGCAAAACCGCTGCACACTTTTGCGCGACATGCTCTGATCCCCCTCATCTGGGGGGGCCTAT- CTGAGGGAATTT CCGATCCG GCTCGCCTGAACCATTCTGCTTTCCACGAACTTGAAAACGCT P.sub.3B5B Promoter.sup.5 TTTTGTTCGATTATCGAACAAATTATTGAAATATCGAACAAAACCTCTAAACTACTGTGGCACTGAATCAAAA- AATTATA AACCCTGATCAG A P.sub.TTg Promoter.sup.19 CACCCAGCAGTATTTACAAACAACCATGAATGTAAGTATATTCCTTAGCAA P.sub.Van Promoter.sup.20 ATTGGATCCAATTGACAGCTAGCTCAGTCCTAGGTACCATTGGATCCAAT

TABLE-US-00006 TABLE 6 RBS sequences used in this study Name Strain RBS sequence.sup.a (SEQ ID NOs: 226-291) Strength (GFP, au) RBSr1 R. sp. IRBG74 ATTTCACACATCTAGAGCTAATCATCTCGTACTAAAGAGGAGAAATTAA 8242 CCATG RBSr2 R. sp. IRBG74 ATTTCACACATCTAGAGCTAATCATCGCGTACTCAGGAGGCAAGTAATG 7181.5 RBSr3 R. sp. IRBG74 ATTTCACACATCTAGAATTAAAGAGGAGAAATTAACCATG 6238.5 RBSr4 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCATCTCGTACTAAAGAGGCAAGTAATG 3618 RBSr5 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCATCGCGTACTAAGGAGGCAAGTAATG 3560 RBSr6 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCATCGCGTACTCAAGAGGCAAGTAATG 2614.5 RBSr7 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCTTCGCGTACTAAAGAGGCAAGTAATG 2418.5 RBSr8 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCATCTCGTACTCAGGAGGCAAGTAATG 1882.5 RBSr9 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCATCTCGTACTAATGAGGCAAGTAATG 1593.5 RBSr10 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCATCGCGTACTAATGAGGCAAGTAATG 1590 RBSr11 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCATCGCGTACTCACGAGGCAAGTAATG 1554 RBSr12 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCATCGCGTACTAAAAAGGCAAGTAATG 1138 RBSr13 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCTTCGCGTACTAAAAAGGCAAGTAATG 895.5 RBSr14 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCTTCGCGTACTAAGAAGGCAAGTAATG 632.5 RBSr15 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCATCTCGTACTAAATAGGCAAGTAATG 648.5 RBSr16 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCATCTCGTACTAATAAGGCAAGTAATG 532 RBSr17 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCTTCTCGTACTAAAGAGGCAAGTAATG 488 RBSr18 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCATCGCGTACTCAATAGGCCAGTAATG 305.5 RBSr19 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCATCGCGTACTAAGTAGGCAAGTAATG 242 RBSr20 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCATCTCGTACTAACGAGGCAAGTAATG 248 RBSr21 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCATCGCGTACTCAGCAGGCAAGTAATG 183 RBSr22 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCTTCGCGTACTAAGTAGGCAAGTAATG 130 RBSr23 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCTTCGCGTACTAATTAGGCAAGTAATG 84.4 RBSr24 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCTTCTCGTACTAACAAGGCAAGTAATG 75.15 RBSr25 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCATCTCGTACTCAATAGGCAAGTAATG 45.45 RBSr26 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCATCTCGTACTAAGCACGCAAGTAATG 36 RBSr27 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCATCGCGTACTAACTACGCAAGTAATG 12.2 RBSr28 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCTTCGCGTACTAAGAACGCAAGTAATG 13 RBSr29 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCTTCGCGTACTAAAAACGCAAGTAATG 4.6 RBSr30 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCTTCGCGTACTAACAACGCAAGTAATG 2.95 RBSr31 R. sp. IRBG74 TAACAATTTCACACATCTAGAGCTAATCTTCTCGTACTCATGACGCAAGTAATG 1.45 RBSr32 R. sp. IRBG74 ATTTCACACATCTAGAATTAAAGAGAAGAAATTAACCATG N/A.sup.b RBSr33 R. sp. IRBG74 CTAGTGCGAACTAGCTCATACCGCAGATG N/A.sup.b RBSp1 P. protegens Pf-5 CTAGCGCAGGTCCAACGTTTTTCTAAGCAAGGAGGTCATATG 25090 RBSp2 P. protegens Pf-5 CTAGCGAAGGTCCAACGTTTTTCTAAGCAAGGAGGTCATATG 21590 RBSp3 P. protegens Pf-5 CTAGCGAAGGTCCAACGTTTTTCTAAGCCAGGAGGTCATATG 19690 RBSp4 P. protegens Pf-5 CTAGCGCAGGTCCAACGTTTTTCTAAGCCAGGAGGTCATATG 19490 RBSp5 P. protegens Pf-5 CTAGCGAAGCTCCAACGTTTTTCTAAGCAAGGAGGTCATATG 17990 RBSp6 P. protegens Pf-5 GAATTCTACACTAACGGACAGGAGGGTCCGATG 14490 RBSp7 P. protegens Pf-5 GAATTCTAAACTAACGGACAGGAGGGTCCGATG 13390 RBSp8 P. protegens Pf-5 GAATTCTAAGCTAACGGACAGGAGGGTCCGATG 12790 RBSp9 P. protegens Pf-5 GAATTCTTAACTAACGGACAGGAGGGTCCGATG 11490 RBSp10 P. protegens Pf-5 GAATTCTACACTAACGGACAGGAGGGTCGGATG 11090 RBSp11 P. protegens Pf-5 GAATTCTACGCTAACGGACAGGAGGGTCCGATG 10390 RBSp12 P. protegens Pf-5 GAATTCTCAACTAACGGACAGGAGGGTCCGATG 9590 RBSp13 P. protegens Pf-5 GAATTCTAAGCTAACGGACAGGAGGGTCGGATG 8918 RBSp14 P. protegens Pf-5 GAATTCTCAGCTAACGGACAGGAGGGTCCGATG 8766 RBSp15 P. protegens Pf-5 GAATTCTCAACTAACGGACAGGAGGGTCCGATG 7596 RBSp16 P. protegens Pf-5 GAATTCTACGCTAACGGACAGGAGGGTCGGATG 6055 RBSp17 P. protegens Pf-5 GAATTCTCAACTAACGGACAGGAGATATACATATG 5939 RBSp18 P. protegens Pf-5 GAATTCTCAGCTAACGGACAGGAGGGTCGGATG 5915 RBSp19 P. protegens Pf-5 GAATTCTAAACTAACGGACAGGAGGGTCGGATG 4867 RBSp20 P. protegens Pf-5 GAATTCTCAGCTCACGGACAGGAGGGTCGGATG 4426 RBSp21 P. protegens Pf-5 GAATTCTCAACTAACGGACAGGAGGGTCGGGATG 4110 RBSp22 P. protegens Pf-5 GAATTCTACACTCACGGACAGGAGGGTCGGATG 3977 RBSp23 P. protegens Pf-5 GAATTCTAAGCTCACGGACAGGAGGGTCGGATG 3829 RBSp24 P. protegens Pf-5 GAATTCTCAACTCACGGACAGGAGGGTCGGATG 3661 RBSp25 P. protegens Pf-5 GAATTCTACACTAACGGACAGCAGGGTCGGATG 3542 RBSp26 P. protegens Pf-5 CTAGCGCAGGTCCAACCTTTTTCTAAGCAAGTAGGTCATATG 2139 RBSp27 P. protegens Pf-5 GAATTCTCAGCTAACGGACAGCAGGGTCGGATG 1265 RBSp28 P. protegens Pf-5 CTAGCGCAGGTCCAACCTTTTTCTAAGCAACTAGGTCATATG 389 RBSp29 P. protegens Pf-5 CTAGCGAAGGTCCAACCTTTTTCTAAGCCAGTAGGTCATATG 377 RBSp30 P. protegens Pf-5 GAATTCTACGCTCACGGACAGCAGGGTCGGATG 221 RBSp31 P. protegens Pf-5 GAATTCTCCGCTCACGGACAGGAGGGTCCGATG 23.3 RBSp32 P. protegens Pf-5 CTTCTCGGCCAGCTGACAGGGGAAGCTCGCATG N/A.sup.b RBSp33 P. protegens Pf-5 CTTCTCGGCCAGCTGACAGGAGGAAGCTCGCATG N/A.sup.b .sup.aThe start codon is underlined. .sup.bRBSs are rationally designed for the controllers by the RBS Calculator.sup.2

TABLE-US-00007 TABLE 7 Chemicals used in this study Chemicals Source Identifier Tryptone Fisher Scientific Cat# BP1421 Yeast extract BD Bacto Cat# DF0127 NaCl Fisher Scientific Cat# S271 CaCl.sub.2.cndot.2H.sub.2O Sigma-Aldrich Cat# C3306 MgSO.sub.4.cndot.7H.sub.2O Fisher Scientific Cat# M80 FeCl.sub.3 Alfa Aesar Cat# AA1235709 Na.sub.2MoO.sub.4.cndot.2H.sub.2O Sigma-Aldrich Cat# 331058 NH.sub.4CH.sub.3CO.sub.2 Sigma-Aldrich Cat# A1542 Na.sub.2HPO.sub.4 Fisher Scientific Cat# S375 KH.sub.2PO.sub.4 Sigma-Aldrich Cat# P9791 EDTA-Na2 Sigma-Aldrich Cat# E5134 ZnSO.sub.4.cndot.7H.sub.2O ACROS Organics Cat# AC424605000 H.sub.3BO.sub.3 Fisher Scientific Cat# A73 MnSO.sub.4.cndot.H.sub.2O MP Biomedicals Cat# ICN225099 CuSO.sub.4.cndot.5H.sub.2O Aldon Corp Cat# CC0535 CoCl.sub.2.cndot.6H.sub.2O Sigma-Aldrich Cat# C8661 FeSO.sub.4.cndot.7H.sub.2O Sigma-Aldrich Cat# 215422 Thiamine hydrochloride ACROS Organics Cat# 148990100 D-pantothenic acid hemicalcium salt Sigma-Aldrich Cat# P5155 Biotin Sigma-Aldrich Cat# B4501 Nicotinic acid Sigma-Aldrich Cat# 72309 MOPS Fisher Scientific Cat# BP308 Isopropyl-beta-D-thiogalactoside (IPTG) GoldBio Cat# I2481 L-arabinose Sigma Cat# A3256 Anhydrotetracycline hydrochloride (aTc) Sigma Cat# 37919 N-(3-Oxohexanoyl)-L-homoserine lactone (3OC6HSL) Sigma Cat# K3007 N-(3-Hydroxytetradecanoyl)-DL-homoserine lactone Sigma Cat# 51481 (3OC14HSL) Naringenin Sigma Cat# N5893 2,4-Diacetylphloroglucinol (DAPG) Santa Cruz Cat# sc-206518 Salicylic acid sodium salt Sigma Cat# S3007 3,4-Dihydroxybenzoic acid (DHBA) Sigma Cat# 37580 Vanillic acid Sigma Cat# 94770 Cuminic acid Sigma Cat# 268402 Nopaline Toronto Research Chemicals Cat# N650600 Octopine Toronto Research Chemicals Cat# O239850 Choline chloride Sigma Cat# C7017 Tris (1M), pH 8.0 Invitrogen Cat# AM9855 Triton X-100 Sigma-Aldrich Cat# T8787 Tergitol solution Sigma-Aldrich Cat# NP40S DNase I Sigma-Aldrich Cat# 4716728001 RNA Fragmentation Reagents Invitrogen Cat# AM8740 T4 Polynucleotide kinase New England Biolabs Cat# M0201 SUPERase.cndot.In Invitrogen Cat# AM2694 PEG 8000 Sigma-Aldrich Cat# 1546605 T4 RNA ligase 2, truncated K277Q New England Biolabs Cat# M0351 SuperScript III reverse transcriptase Invitrogen Cat# 18080044 CircLigase ssDNA ligase Epicentre Cat# CL4115K Phusion High-Fidelity DNA polymerase New England Biolabs Cat# M0530 Micrococcal nuclease Roche 10107921001

Sequence CWU 1

1

293117DNAArtificial SequenceSynthetic polynucleotidemisc_feature(1)..(1)may be modified by /5rApp/misc_feature(17)..(17)may be modified by /3ddc/ 1ctgtaggcac catcaat 17233DNAArtificial SequenceSynthetic polynucleotidemisc_feature(1)..(1)may be modified by /5Phos/misc_feature(33)..(33)may be modified by /iSp18/ 2agatcggaag agcgtcgtgt agggaaagag tgt 33341DNAArtificial SequenceSynthetic polynucleotidemisc_feature(1)..(1)may be modified by /iSp18/ 3caagcagaag acggcatacg agatattgat ggtgcctaca g 41421DNAArtificial SequenceSynthetic polynucleotide 4caagcagaag acggcatacg a 21585DNAArtificial SequenceSynthetic polynucleotidemisc_feature(63)..(68)n is a, c, g, or t 5aatgatacgg cgaccaccga gatctacacg atcggaagag cacacgtctg aactccagtc 60acnnnnnnac actctttccc tacac 85632DNAArtificial SequenceSynthetic polynucleotide 6cgacaggttc agagttctac agtccgacga tc 32732DNAArtificial SequenceSynthetic polynucleotide 7cgacaggttc agagttctac agtccgacga tc 32868DNAKlebsiella oxytoca 8cgtagggcgc attaatgcag ctggcacgac aggtgaattc tagactgctg gatacgctgc 60ttaaggtc 68924DNAKlebsiella oxytoca 9tacgctgttt gagctggcaa acct 241074DNAPseudomonas stutzeri 10gcccggagag caagcccgta gggcgcatta atgcagctgg cacgacaggt gttaggttgg 60cctgaattcg gtgt 741148DNAPseudomonas stutzeri 11ggctcacttc gatttcgtcc gcggtgcgtg ccctgctagt gatgcgta 481225DNAPseudomonas stutzeri 12cgcctgattt cgcctgatga acagg 251320DNAPseudomonas stutzeri 13tgacgctgtt gaccaccgcc 201423DNAPseudomonas stutzeri 14atggaagtgg tcggcaccgg cta 231522DNAPseudomonas stutzeri 15cgcaacggtt ggggtaggtt gg 221623DNAPseudomonas stutzeri 16gacgtccatc gcttcggctt cga 231737DNAPseudomonas stutzeri 17ctgcgaaatc gacgctgtcg agcatcatcg cggttca 3718101DNAAzotobacter vinelandii 18atccattctc aggctgtctc gtctcgtctc tacgtacgcg gatcccaggc aacgtcttcg 60tactgcggta ccgggttgcg ggggcagcca gtggaaaaag g 1011921DNAAzotobacter vinelandii 19ctacggcacg ccctggttcg a 212022DNAAzotobacter vinelandii 20gctcggaaag tgctggagaa ac 222124DNAAzotobacter vinelandii 21aaatcagaca ttcatggcca cagg 242222DNAAzotobacter vinelandii 22tctaccatgg cgtgactctc gg 222343DNAAzotobacter vinelandii 23actcgtcttc tgtccgttta aactcccgga actctaccac cgc 432421DNAAzotobacter vinelandii 24cttggataga cgaggcacag c 212536DNAAzotobacter vinelandii 25gccggctcct gcaacctgaa ggggccgagg atgatg 362630DNAPaenibacillus polymyxa 26gaattgagga taaatgtcag ggatttcatg 302724DNAPaenibacillus polymyxa 27ccaagcattt tgagatcgcg gatg 242821DNAPaenibacillus polymyxa 28cggaggtgcc ggtatgagcg a 212922DNAPaenibacillus polymyxa 29gaagtttgca gcgaaagagg cg 223023DNAPaenibacillus polymyxa 30gggatgatgc agaatacatc ccg 233126DNAPaenibacillus polymyxa 31ggtgacctgg atgatgcaga ggagag 2632118DNAUnknownCyanothece 32ggcccgcgtt aggttggcct gaattcggtg tgtatccccc ggagatacgt aaaaaaaaaa 60accccgccct gtcaggggcg gggttttttt ttgataagtc aagctatcag aaccgatc 1183348DNAUnknownCyanothece 33taattcccat aacatctgca tgcataataa ggtggggaaa gtctcagc 483424DNAUnknownCyanothece 34aatgtatttc tgatcgatgc gacg 243524DNAUnknownCyanothece 35gttatctggc tgatgtttgt ggtg 243624DNAUnknownCyanothece 36gtcaaactgt cttgtttaaa gccg 2437104DNAAzospirillum brasilense 37ttaaggtcat gcagcaggag aactaaaggc ccgcgttagg ttggtaataa aaaagccccc 60ggaatgatct tccgggggcc ctgcgcaaat acaacatcga gatc 1043826DNAAzospirillum brasilense 38gacgactgaa taaggatcgc ggaatg 263923DNAAzospirillum brasilense 39tatgtcacag gcccgacaaa gcg 234023DNAAzospirillum brasilense 40gattgtcggg tatcgcacac gag 234125DNAAzospirillum brasilense 41cgaaggagtt cgccccagtc tattc 254268DNARhodopseudomonas palustris 42aatacgatcg catgtcctag gtaatacgac tcactatagg gagaggtaat cagtggtgga 60tttgatgt 684320DNARhodopseudomonas palustris 43ccaagcaaag gaccaccctc 204422DNARhodopseudomonas palustris 44agcttcgata tcatccgctg at 224523DNARhodopseudomonas palustris 45ttgttcatgt cggacctaac cga 234667DNARhodobacter sphaeroides 46caatacgatc gcatgtccta ggtaatacga ctcactatag ggagatgcat ttcacgcttc 60gcgattc 674720DNARhodobacter sphaeroides 47ccgccttcac cagagacacc 204823DNARhodobacter sphaeroides 48atcgagaagt tctacgatgc cgt 234968DNARhodobacter sphaeroides 49gcaaaaaaaa accccgcccc tgacagggcg gggttttttt tttcaattgg acctggatgg 60gcagcaag 6850106DNAAzorhizobium caulinodans 50ctcgcatcca ttctcaggct gtctcgtctc gtctctctag agtcggagct cttggggcct 60ctaaacgggt cttgaggggt tttttgttgt cttcgacgcg aagctc 1065153DNAAzorhizobium caulinodans 51ataggcaata cgatcgcatg tccgtttaaa ctgataagga cggcactggc tgg 535219DNAAzorhizobium caulinodans 52cgatgccgtc cagcacctc 195321DNAAzorhizobium caulinodans 53ctgccacggt tcccaaggtt c 215462DNAAzorhizobium caulinodans 54taaaaaagcg gctaaccacg ccgctttttt tacgtctgca gtgttgtcga agcttgatgc 60gc 625560DNAAzorhizobium caulinodans 55cgctgcttaa ggtcatgcag caggagaact aaaggcccgc tctgcgaaag gaatagcgtc 605619DNAAzorhizobium caulinodans 56ctatcgccgc cacctgacc 195730DNAAzorhizobium caulinodans 57cgtcagaacg gctctgacgc atcagggaga 305832DNAAzorhizobium caulinodans 58agtaatattg cggatcggcc agcagcgagg aa 325925DNAAzorhizobium caulinodans 59ggtggtcatt ggcaacggtt cgaag 256031DNAAzorhizobium caulinodans 60tccccaagag cccaaccgtt ccgggagcga a 316199DNAGluconacetobacter diazotrophicus 61ttaaggtcat gcagcaggag aactaaaggc ccgcgttagg ttggtaataa aaaagccccc 60ggaatgatct tccgggggcc gatcgaggaa atcgacgtg 996228DNAGluconacetobacter diazotrophicus 62atattccgga tacggctggt gaggtgga 286324DNAGluconacetobacter diazotrophicus 63cgccacgtcg tcaatgccta taac 246421DNAGluconacetobacter diazotrophicus 64tgaccaccgt gcagaagatc c 216523DNAKlebsiella oxytoca 65gtgacgctcg cgtatcaggt ttg 236669DNAKlebsiella oxytoca 66atcaggcgca tatttgaatg tatttactgc agcggccgct tctagagtga ccaaaagctt 60ccgcaaccc 696748DNAPseudomonas stutzeri 67actacgcatc actagcaggg cacgcaccgc ggacgaaatc gaagtgag 486822DNAPseudomonas stutzeri 68ttgtcgactc ccggggtctg ac 226923DNAPseudomonas stutzeri 69ggctttaacg gcatgttccg ggt 237024DNAPseudomonas stutzeri 70gtagtcgtcg ttgtggccga actc 247122DNAPseudomonas stutzeri 71aaagcatcat ctcgggtcgg gc 227221DNAPseudomonas stutzeri 72cgtcgagcga caacgcctcg a 217325DNAPseudomonas stutzeri 73ctatgagctg gactgaaccg cgatg 257474DNAPseudomonas stutzeri 74gaaaataccg catcaggcgc atatttgaat gtatttactg cagcggccgc tggcgaatct 60ccttcctcgg ttcg 747522DNAAzotobacter vinelandii 75gccttcgaac atgttgtccc ag 227624DNAAzotobacter vinelandii 76tcgagttcga gcagtttctc cagc 247720DNAAzotobacter vinelandii 77agcgaacaat acctgtggcc 207821DNAAzotobacter vinelandii 78tggcgcttgc ccttgttcca a 217954DNAAzotobacter vinelandii 79gcgcggtggt agagttccgg gagtttaaac ggacagaaga cgagtcgtgc gggc 548020DNAAzotobacter vinelandii 80ttgctcaggg tcgggttggc 208139DNAAzotobacter vinelandii 81catcatcctc ggccccttca ggttgcagga gccggcttg 398221DNAAzotobacter vinelandii 82gcaagccact ccactgacga a 218322DNAPaenibacillus polymyxa 83acaggttccg cagttcacaa gc 228425DNAPaenibacillus polymyxa 84gctgattgtg atcgacaata ttcgg 258522DNAPaenibacillus polymyxa 85gaaagcctac acgaagcaaa gg 228622DNAPaenibacillus polymyxa 86cttgagaatc tgccgggcgc ct 228722DNAPaenibacillus polymyxa 87atccacaaat caacaccctg cg 228822DNAPaenibacillus polymyxa 88aaagcgttcc agtcacggtc ac 228948DNAUnknownCyanothece 89gagactttcc ccaccttatt atgcatgcag atgttatggg aattaacg 489023DNAUnknownCyanothece 90accttgacaa tcattacaca gcg 239128DNAUnknownCyanothece 91caaatataat gatcgacatt ttcaccac 289224DNAUnknownCyanothece 92cgttaacttt gtcgcaaaac ttcg 2493102DNAUnknownCyanothece 93accaaggcga atctccttcc tcggttcgcg atcacgctac tccgccaata aaaaagcccc 60cggaatgatc ttccgggggc cagattcagg taactgctca ag 1029423DNAAzospirillum brasilense 94tgcgtcttct tcgggcatcg tca 239523DNAAzospirillum brasilense 95agaaaattga ttgcggacga gcg 239627DNAAzospirillum brasilense 96ttcaataagt taagcagatc ggcctcg 279733DNAAzospirillum brasilense 97cggtgttacg aataaatatt tctacgaata gac 339868DNAAzospirillum brasilense 98gctccaaaag gagcctttaa ttgtatcggt ttatcagctt gctttgttcc gcgggtctcg 60atacaacg 689922DNARhodopseudomonas palustris 99ggtcttgcgg atcatcactt tc 2210020DNARhodopseudomonas palustris 100gacggtcagg tggtccgaac 2010123DNARhodopseudomonas palustris 101ggtgagaatg atcatgatcg gcc 2310267DNARhodopseudomonas palustris 102ctccaaaagg agcctttaat tgtatcggtt tatcagcttg ctttgacgac aagtggagaa 60gggatag 6710322DNARhodobacter sphaeroides 103tcccatggtc atgtcctttg cg 2210421DNARhodobacter sphaeroides 104gtgcgctttt ccacgaggag c 2110566DNARhodobacter sphaeroides 105aattgaaaaa aaaaaccccg ccctgtcagg ggcggggttt ttttttgcag cgcccattcc 60gtcttc 6610666DNARhodobacter sphaeroides 106gctccaaaag gagcctttaa ttgtatcggt ttatcagctt gctttggaga aagcctgcgc 60ggctag 6610765DNAAzorhizobium caulinodans 107gcccccggaa ggtgatcttc cgggggcttt ctcatgcgtt gacagccttg agatagatca 60agtgc 6510820DNAAzorhizobium caulinodans 108ctgatccagg ccttcatcgg 2010923DNAAzorhizobium caulinodans 109gacatgtctg gtctccttgg aac 2311042DNAAzorhizobium caulinodans 110ttctggaatt tggtaccgag tcagtaacgt gccacagcct cg 42111117DNAAzorhizobium caulinodans 111atcaggcgca tatttgaatg tatttactgc agcggccgct acgtacttgt ggggtcagtt 60ccggctgggg gttcagcagc cacctgcagt taattaaggc gctcctttcc tgattcg 11711220DNAAzorhizobium caulinodans 112gctgctgtgt ggagagatcg 2011322DNAAzorhizobium caulinodans 113gtcggtgaga ttgatcatgg cc 2211420DNAAzorhizobium caulinodans 114tgcatgtccg ttcctcgctg 2011524DNAAzorhizobium caulinodans 115acatgtcttg aattccttcg aacc 2411618DNAAzorhizobium caulinodans 116tgcattgcgt tcgctccc 1811719DNAAzorhizobium caulinodans 117tgtcagggca ggcagggcc 1911841DNAGluconacetobacter diazotrophicus 118tcaccagccg tatccggaat atgtcaggat catgacatcc c 4111920DNAGluconacetobacter diazotrophicus 119acgatttcca tgcccaggtc 2012020DNAGluconacetobacter diazotrophicus 120cctccagcac ctcttcgatg 2012167DNAGluconacetobacter diazotrophicus 121gctccaaaag gagcctttaa ttgtatcggt ttatcagctt gctttgggca atacctgaga 60cgtttca 6712270DNAArtificial SequenceSynthetic polynucleotide 122agagtgttga cttgtgagcg gataacaatg atacttagat tcaattgtga gcggataaca 60atttcacaca 701232652DNAArtificial SequenceSynthetic polynucleotide 123atgaacacga ttaacatcgc taagaacgac ttctctgaca tcgaactggc tgctatcccg 60ttcaacactc tggctgacca ttacggtgag cgtttagctc gcgaacagtt ggcccttgag 120catgagtctt acgagatggg tgaagcacgc ttccgcaaga tgtttgagcg tcaacttaaa 180gctggtgagg ttgcggataa cgctgccgcc aagcctctca tcactaccct actccctaag 240atgattgcac gcatcaacga ctggtttgag gaagtgaaag ctaagcgcgg caagcgcccg 300acagccttcc agttcctgca agaaatcaag ccggaagccg tagcgtacat caccattaag 360accactctgg cttgcctaac cagtgctgac aatacaaccg ttcaggctgt agcaagcgca 420atcggtcggg ccattgagga cgaggctcgc ttcggtcgta tccgtgacct tgaagctaag 480cacttcaaga aaaacgttga ggaacaactc aacaagcgcg tagggcacgt ctacaagaaa 540gcatttatgc aagttgtcga ggctgacatg ctctctaagg gtctacttgg tggcgaggcg 600tggtcttcgt ggcataagga agactctatt catgtaggag tacgctgcat cgagatgctc 660attgagtcaa ccggaatggt tagcttacac cgccaaaatg ctggcgtagt aggtcaagac 720tctgagacta tcgaactcgc acctgaatac gctgaggcta tcgcaacccg tgcaggtgcg 780ctggctggca tctctccgat gttccaacct tgcgtagttc ctcctaagcc gtggactggc 840attactggtg gtggctattg ggctaacggt cgtcgtcctc tggcgctggt gcgtactcac 900agtaagaaag cactgatgcg ctacgaagac gtttacatgc ctgaggtgta caaagcgatt 960aacattgcgc aaaacaccgc atggaaaatc aacaagaaag tcctagcggt cgccaacgta 1020atcaccaagt ggaagcattg tccggtcgag gacatccctg cgattgagcg tgaagaactc 1080ccgatgaaac cggaagacat cgacatgaat cctgaggctc tcaccgcgtg gaaacgtgct 1140gccgctgctg tgtaccgcaa ggacaaggct cgcaagtctc gccgtatcag ccttgagttc 1200atgcttgagc aagccaataa gtttgctaac cataaggcca tctggttccc ttacaacatg 1260gactggcgcg gtcgtgttta cgctgtgtca atgttcaacc cgcaaggtaa cgatatgacc 1320aaaggactgc ttacgctggc gaaaggtaaa ccaatcggta aggaaggtta ctactggctg 1380aaaatccacg gtgcaaactg tgcgggtgtc gacaaggttc cgttccctga gcgcatcaag 1440ttcattgagg aaaaccacga gaacatcatg gcttgcgcta agtctccact ggagaacact 1500tggtgggctg agcaagattc tccgttctgc ttccttgcgt tctgctttga gtacgctggg 1560gtacagcacc acggcctgag ctataactgc tcccttccgc tggcgtttga cgggtcttgc 1620tctggcatcc agcacttctc cgcgatgctc cgagatgagg taggtggtcg cgcggttaac 1680ttgcttccta gtgaaaccgt tcaggacatc tacgggattg ttgctaagaa agtcaacgag 1740attctacaag cagacgcaat caatgggacc gataacgaag tagttaccgt gaccgatgag 1800aacactggtg aaatctctga gaaagtcaag ctgggcacta aggcactggc tggtcaatgg 1860ctggcttacg gtgttactcg cagtgtgact aagcgttcag tcatgacgct ggcttacggg 1920tccaaagagt tcggcttccg tcaacaagtg ctggaagata ccattcagcc agctattgat 1980tccggcaagg

gtctgatgtt cactcagccg aatcaggctg ctggatacat ggctaagctg 2040atttgggaat ctgtgagcgt gacggtggta gctgcggttg aagcaatgaa ctggcttaag 2100tctgctgcta agctgctggc tgctgaggtc aaagataaga agactggaga gattcttcgc 2160aagcgttgcg ctgtgcattg ggtaactcct gatggtttcc ctgtgtggca ggaatacaag 2220aagcctattc agacgcgctt gaacctgatg ttcctcggtc agttccgctt acagcctacc 2280attaacacca acaaagatag cgagattgat gcacacaaac aggagtctgg tatcgctcct 2340aactttgtac acagccaaga cggtagccac cttcgtaaga ctgtagtgtg ggcacacgag 2400aagtacggaa tcgaatcttt tgcactgatt cacgactcct tcggtacgat tccggctgac 2460gctgcgaacc tgttcaaagc agtgcgcgaa actatggttg acacatatga gtcttgtgat 2520gtactggctg atttctacga ccagttcgct gaccagttgc acgagtctca attggacaaa 2580atgccagcac ttccggctaa aggtaacttg aacctccgtg acatcttaga gtcggacttc 2640gcgttcgcgt aa 265212451DNAA. caulinodans 124cgaatggtgc aaaacctttc gcggtatggc atgatagcgc ccggaagaga g 511251545DNAArtificial SequenceSynthetic polynucleotide 125atggcgatga gcccaaagat ggagttccgc cagagccagt ctctggtgat gacgccgcag 60ctgatgcagg ccatcaagct gctgcagctc tccaatctcg aactggtcgc ctatgtggag 120gccgagctcg aacgcaatcc gctgctggag cgggcgagcg agccggaaag ccccgagcac 180gatccgccga acccgcagga agaggcaccc accccgcctg acagtggcgc gccggtgtcc 240ggcgactgga tggaaagcga catgggctcg agccgcgagg ccatcgagac ccggctggac 300accgacctcg gcaatgtctt tcccgatgat gcgccggccg agcgcatcgg cgcgggcagc 360ggcagcggct cgtccatcga atggggctcg ggcggcgacc ggggcgagga ctacaatccg 420gaagccttcc tcgctgccga gacgacgctg gccgaccatc tggaagccca gctctccgtg 480gcggagcccg atccggcgcg ccgcctcatc ggcctcaacc tcatcggcct catcgacgag 540acgggttatt tctccggcga cctcgatgcg gtggccgagc aactgggcgc cacccacgat 600caggtggccg acgtgctgcg cgtcatccag agcttcgagc cgtccggcgt cggcgcacgg 660tcgctcagcg aatgcctggc cctgcaattg cgcgacaagg atcgctgcga tcccgccatg 720caggcgctgc tcgacaatct ggaactcctc gcccgccacg accgcaacgc gctgaagcgc 780atctgcgggg tggacgcgga agacctcgcg gacatgatcg gcgagatccg ccgcctcgat 840ccgaagcccg gcctcgccta tggcggcggc gtcgtccacc cgctggtgcc ggacgtgttc 900gtgcgcgagg gctccgacgg cagctggatc gtggaactga attccgagac gctgccgcgc 960gtgctggtga accagaccta tcacgcgacg gtggccaagg cggcgcgctc ggccgaggaa 1020aagaccttcc tcgccgactg cctccagagc gcctcctggc ttacccgctc gctcgaccag 1080cgggctcgca ccatcctcaa ggtggcgagc gagatcgtgc gccagcagga cgccttcctc 1140gtgcacggcg tgcggcacct gcgccccctg aacctgcgca cggtggcgga tgccatcggc 1200atgcacgaat ccaccgtctc gcgggtgacc tcgaacaagt acatctccac cccgcgcggg 1260gtgctggaga tgaagttctt cttctcctcc tccatcgctt cctcgggtgg tggcgaggcc 1320catgcggcgg aggcggtgcg ccaccgcatc aagagcctca tcgaggccga gagtgcggac 1380gacgtgctgt ccgacgacac gctggtgcag aagctgaagg acgacggcat cgatatcgcc 1440cgccgaacgg tcgcgaaata tcgcgagagc atgaacatcc cgtcctcggt ccagcgccgc 1500cgcgaaaagc aggccctgcg cagcgacgcc gccgccgccg gctga 15451261083DNAArtificial SequenceSynthetic polynucleotide 126gtgaaaccag taacgttata cgatgtcgca gagtatgccg gtgtctctta tcagaccgtt 60tcccgcgtgg tgaaccaggc cagccacgtt tctgcgaaaa cgcgggaaaa agtggaagcg 120gcgatggcgg agctgaatta cattcccaac cgcgtggcac aacaactggc gggcaaacag 180tcgttgctga ttggcgttgc cacctccagt ctggccctgc acgcgccgtc gcaaattgtc 240gcggcgatta aatctcgcgc cgatcaactg ggtgccagcg tggtggtgtc gatggtagaa 300cgaagcggcg tcgaagcctg taaagcggcg gtgcacaatc ttctcgcgca acgcgtcagt 360gggctgatca ttaactatcc gctggatgac caggatgcca ttgctgtgga agctgcctgc 420actaatgttc cggcgttatt tcttgatgtc tctgaccaga cacccatcaa cagtattatt 480ttctcccatg aagacggtac gcgactgggc gtggagcatc tggtcgcatt gggtcaccag 540caaatcgcgc tgttagcggg cccattaagt tctgtctcgg cgcgtctgcg tctggctggc 600tggcataaat atctcactcg caatcaaatt cagccgatag cggaacggga aggcgactgg 660agtgccatgt ccggttttca acaaaccatg caaatgctga atgagggcat cgttcccact 720gcgatgctgg ttgccaacga tcagatggcg ctgggcgcaa tgcgcgccat taccgagtcc 780gggctgcgcg ttggtgcgga tatctcggta gtgggatacg acgataccga agacagctca 840tgttatatcc cgccgttaac caccatcaaa caggattttc gcctgctggg gcaaaccagc 900gtggaccgct tgctgcaact ctctcagggc caggcggtga agggcaatca gctgttgccc 960gtctcactgg tgaaaagaaa aaccaccctg gcgcccaata cgcaaaccgc ctctccccgc 1020gcgttggccg attcattaat gcagctggca cgacaggttt cccgactgga aagcgggcag 1080tga 1083127717DNAArtificial SequenceSynthetic polynucleotide 127atgagtaaag gagaagaact tttcactgga gttgtcccaa ttcttgttga attagatggt 60gatgttaatg ggcacaaatt ttctgttagt ggagagggtg aaggtgatgc aacatacgga 120aaacttaccc ttaaatttat ttgcactact ggaaaactac ctgttccatg gccaacactt 180gtcactactt tcggttatgg tgttcaatgc tttgcgagat acccagatca tatgaaacag 240catgactttt tcaagagtgc catgcccgaa ggttatgtac aggaaagaac tatatttttc 300aaagatgacg ggaactacaa gacacgtgct gaagtcaagt ttgaaggtga tacccttgtt 360aatagaatcg agttaaaagg tattgatttt aaagaagatg gaaacattct tggacacaaa 420ttggaataca actataactc acacaatgta tacatcatgg cagacaaaca aaagaatgga 480atcaaagtta acttcaaaat tagacacaac attgaagatg gaagcgttca actagcagac 540cattatcaac aaaatactcc aattggcgat ggccctgtcc ttttaccaga caaccattac 600ctgtccacac aatctgccct ttcgaaagat cccaacgaaa agagagacca catggtcctt 660cttgagtttg taacagctgc tgggattaca catggcatgg atgaactata caaatag 717128717DNAArtificial SequenceSynthetic polynucleotide 128atgcgtaaag gcgaagagct gttcactggt gtcgtcccta ttctggtgga actggatggt 60gatgtcaacg gtcataagtt ttccgtgcgt ggcgagggtg aaggtgacgc aactaatggt 120aaactgacgc tgaagttcat ctgtactact ggtaaactgc cggtaccttg gccgactctg 180gtaacgacgc tgacttatgg tgttcagtgc tttgctcgtt atccggacca tatgaagcag 240catgacttct tcaagtccgc catgccggaa ggctatgtgc aggaacgcac gatttccttt 300aaggatgacg gcacgtacaa aacgcgtgcg gaagtgaaat ttgaaggcga taccctggta 360aaccgcattg agctgaaagg cattgacttt aaagaagacg gcaatatcct gggccataag 420ctggaataca attttaacag ccacaatgtt tacatcaccg ccgataaaca aaaaaatggc 480attaaagcga attttaaaat tcgccacaac gtggaggatg gcagcgtgca gctggctgat 540cactaccagc aaaacactcc aatcggtgat ggtcctgttc tgctgccaga caatcactat 600ctgagcacgc aaagcgttct gtctaaagat ccgaacgaga aacgcgatca tatggttctg 660ctggagttcg taaccgcagc gggcatcacg catggtatgg atgaactgta caaatga 717129678DNAArtificial SequenceSynthetic polynucleotide 129atggcttcct ccgaagacgt tatcaaagag ttcatgcgtt tcaaagttcg tatggaaggt 60tccgttaacg gtcacgagtt cgaaatcgaa ggtgaaggtg aaggtcgtcc gtacgaaggt 120acccagaccg ctaaactgaa agttaccaaa ggtggtccgc tgccgttcgc ttgggacatc 180ctgtccccgc agttccagta cggttccaaa gcttacgtta aacacccggc tgacatcccg 240gactacctga aactgtcctt cccggaaggt ttcaaatggg aacgtgttat gaacttcgaa 300gacggtggtg ttgttaccgt tacccaggac tcctccctgc aagacggtga gttcatctac 360aaagttaaac tgcgtggtac caacttcccg tccgacggtc cggttatgca gaaaaaaacc 420atgggttggg aagcttccac cgaacgtatg tacccggaag acggtgctct gaaaggtgaa 480atcaaaatgc gtctgaaact gaaagacggt ggtcactacg acgctgaagt taaaaccacc 540tacatggcta aaaaaccggt tcagctgccg ggtgcttaca aaaccgacat caaactggac 600atcacctccc acaacgaaga ctacaccatc gttgaacagt acgaacgtgc tgaaggtcgt 660cactccaccg gtgcttaa 678130711DNAArtificial SequenceSynthetic polynucleotide 130atggtttcga agggcgagga ggataacatg gccatcatca aggagttcat gcgcttcaag 60gtgcacatgg agggctccgt gaacggccac gagttcgaga tcgagggcga gggcgagggc 120cgcccctacg agggcaccca gaccgccaag ctgaaggtga ccaagggtgg ccccctgccc 180ttcgcctggg acatcctgtc ccctcagttc atgtacggct ccaaggccta cgtgaagcac 240cccgccgaca tccccgacta cttgaagctg tccttccccg agggcttcaa gtgggagcgc 300gtgatgaact tcgaggacgg cggcgtggtg accgtgaccc aggactcctc cttgcaggac 360ggcgagttca tctacaaggt gaagctgcgc ggcaccaact tcccctccga cggccccgta 420atgcagaaga agacgatggg ctgggaggcc tcctccgagc ggatgtaccc cgaggacggc 480gccctgaagg gcgagatcaa gcagaggctg aagctgaagg acggcggcca ctacgacgct 540gaggtcaaga ccacctacaa ggccaagaag cccgtgcagc tgcccggcgc ctacaacgtc 600aacatcaagt tggacatcac ctcccacaac gaggactaca ccatcgtgga acagtacgaa 660cgcgccgagg gccgccactc caccggcggc atggacgagc tgtacaagta a 71113123DNAArtificial SequenceSynthetic polynucleotide 131taatacgact cactataggg aga 2313223DNAArtificial SequenceSynthetic polynucleotide 132taatacgact cactacaggc aga 2313323DNAArtificial SequenceSynthetic polynucleotide 133taatacgact cactagagag aga 2313423DNAArtificial SequenceSynthetic polynucleotide 134taatacgact cactaatggg aga 2313523DNAArtificial SequenceSynthetic polynucleotide 135taatacgact cactaaaggg aga 2313623DNAArtificial SequenceSynthetic polynucleotide 136taatacgact cactataggt aga 2313723DNAA. caulinodans 137taatacgact cactattggg aga 231381221DNAK. oxytoca 138gtgttccgtg ggaggcctgc catgctcgcc aagacacccg caaaccccgc gccgcttcag 60cggacggcgt tcctgaacga caccacgctg cgcgacggcg agcaggcgcc gggtgtcgcc 120ttcacccgca aggagaagat cgagatcgcc gccgcccttg ccgccgccgg tgtcccggag 180atcgaggcgg gaacgcccgc catgggcgac gaagaggtgg aaaccatccg ctccatcgtc 240tcgctgaacc tcccgacgcg cgtcatggcc tggtgccgca tgagcgagga cgacctgatg 300gccgccgtcg cggcgggcgt gaagatcgtc aatgtctcca ttcccacctc cgaccggcaa 360ctggccggca agctcggcaa ggatcgcgcc tgggcgctcg gccgtgtggc ggaggtggtg 420acactggcgc gtcggctcgg ctttgaggtg gcggtagggg gcgaggattc ctcgcgggcc 480gatcccgatt ttctctgccg tctcgcggag acggcgaagg cggcgggcgc ctttcgcctg 540cggctggccg acacgcttgg cgtgcttgac cccttcggca cctatgcatt ggtgcgccgg 600gtggccgcca ccaccgacat cgagcttgag ttccacgccc atgacgatct cggccttgcc 660accgccaata cgctggcggc ggtgatgggc ggagcgcgtc acgccagcgt caccgtcgcc 720gggctcggcg agcgcgcggg caatgccgcg ctggaggaag tggccatcgc cctgcgccag 780acggcgcggg cggagaccgg catcgctccg gccgcgctga agccgctggc cgaactagtg 840tgcggcgccg ccgcccgtcc ggtgccgcgc ggcaaggcca tcgtcggcgc ggatgtgttc 900acccacgagt cgggcatcca tgtctccggc ctgctcaagg accgggccac ctatgaagct 960ctgaatccgg aactgttcgg gcgtggccac acggtggtgc tcggaaagca ttccggtctt 1020gcggcggtgg agaaggcgct ggccgacgag ggcatcaccg tggatgcggt gcgcgggcgc 1080gccattctcg accgggtgcg ggcttttgct gtccgcacca aggagaatgt ttcccgcgag 1140acgctgctgc gcttctatca ggacagcttc accgagtccg cgctgcgtct gcggcgggcc 1200gccgtggaag gcgcaatctg a 1221139323DNAP. stutzeri 139tgttgcctca agcacagcct gtgccagctc gcggatgaca gaagagttag cgcgaattca 60acgcgttatg aagagagtcg ccgcgcagcg cgccaagaga ttgcgtggaa taagacacag 120ggggcgacaa gctgttgaac aggcgacaaa gcgccaccat ggccccggca ggcgcaattg 180ttctgtttcc cacatttggt cgccttattg tgccgttttg ttttacgtcc tgcgcggcga 240caaataacta acttcataaa aatcataaga atacataaac aggcacggct ggtatgttcc 300ctgcacttct ctgctggcaa aca 323140233DNAA. vinelandii 140tgtcatgttc gcaacagttg ccgaaagtgt ggaaaaccgg cgcttggccc ggccgatctt 60tttgtcgcca ttgcaacagt caggcctgtc ggttgttaac tatcgaaccg ccgaaggatg 120ttgctagtaa ttaaattatt ctaattaaaa caagtgctta gattatttta gaaacgctgg 180cacaaaggct gctattgccc tgttgcgcag gcttgttcgt gcctatagcc cac 233141256DNAUnknownR. sp. IRBG74 141tgtcagtttt gtcacagggg gccggaccag gatggtggac gctcgatggg gatgtcgggc 60cattgttcgg ttgtagcaat tacaacagtc ggagtagggg gattgtaggg ggattgttgt 120gtatcagacc gccctgcagc tcccgtcgat ggataattaa tcatttaaaa tcaatggttt 180atttatgtgt tgcgggtgct ggcacagacg ctgcattacc tttggtgcgc ggagttgttc 240gggcttacgg ccgaac 256142294DNAA. caulinodans 142ttgacaaagc ctccgagaag agcgccccct aacccctcct cagccctgat cggcagtatc 60atcttgtcga atcctaacgt ctgataggca acgctatacg acaaacgctg gttacaattg 120tcggttccgc gacaagaatt tgctttgtct ggcgggtggt ctattttgag ctaagtagct 180gagaaatcag gaaaacaaaa ctctattcgg tctacccgac gagttggcac gggtcttgta 240accatccttg cgcaggcggc gaaagccacc ggcgatattc atgttgcggg caac 294143215DNAK. oxytoca 143tgtcgcgttt gaaacacggg gcttttggaa ccgttcgatt ctgcaatgca ctgattttac 60ttgattaatt cgaccacacg accactggca cacccgttgc aaaacccctt ggtgcaggcg 120acgggttgcc ggtctggttc gcggatctcc tcgatccccg gctaccgacc cgcctccgaa 180aagtccggtc ccgatccagt tcggcggggc cacac 2151441575DNAP. stutzeri 144atgatccata aatccgattc ggacaccacc gtcagacgtt tcgatctctc ccagcagttt 60accgccatgc agcggataag cgtggtcctg agtcgcgcca ccgaagcgag caaaaccctg 120caggaggttc tgagcgtgct acataacgat gcctttatgc agcacgggat gatttgcctg 180tacgacagcc agcaggagat cctgagcatc gaagcgctgc agcaaacgga agatcagacg 240ctgcccggca gtacgcaaat tcgctaccgg ccgggggaag gattagtcgg taccgtgctg 300gcgcagggcc agtcgctggt gctgccgcgc gtcgccgacg accagcgttt tctcgatcgt 360ctgagcctgt acgactatga cctgccgttt atcgccgttc cgctgatggg cccccactcc 420cggcccatcg gcgtactggc ggcgcagccg atggcgcgtc aggaagagcg gctgcccgcc 480tgcacgcgct ttctcgaaac cgtcgccaat ctgatcgccc agacgattcg cctgatgatc 540ctgccaacct ccgccgcgca ggcgccgcag cagagcccca gaatagagcg cccgcgcgcc 600tgtacccctt cgcgcggttt cggcctggaa aatatggtcg gtaaaagccc ggcgatgcgg 660cagattatgg atattattcg tcaggtttcc cgctgggata ccacggtgct ggtacgcggc 720gagagcggca ccgggaaaga gctcatcgcc aacgccatcc accataattc tccgcgcgcc 780gccgcggcgt tcgtcaaatt taactgcgcg gcgctgccgg acaacctgct ggagagcgag 840ctgtttggtc atgagaaagg cgcgtttacc ggcgcggtgc gccagcggaa aggccgcttt 900gagctggcgg acggcggcac cttattcctc gatgagatcg gcgaaagcag cgcctcgttt 960caggctaagc tactgcgtat tctgcaagag ggggagatgg agcgcgtcgg cggcgacgaa 1020accctgcggg tcaacgtgcg cattatcgcg gcgaccaacc gccatctgga agaggaggtg 1080cggctgggtc atttccgcga ggatctatac taccgcctga acgtaatgcc tatcgcgctg 1140ccgccgctgc gcgagcgcca ggaggatatc gccgagctgg cgcactttct ggtgcgaaaa 1200atcgcccaca gccaggggcg aacgctgcgc atcagcgatg gggcgattcg cctgctgatg 1260gagtacagct ggccgggaaa cgtgcgcgaa ctggaaaact gtctcgaacg ttcggcggtg 1320ctgtcggaaa gcggcctgat agaccgggac gtgattctgt tcaaccatcg cgataacccg 1380ccgaaagcgc tcgccagcag cggcccggcg gaggacggct ggctcgataa cagcctcgac 1440gagcgccagc ggctgatcgc cgccctggaa aaagcgggct gggtgcaggc caaagcggcg 1500cggctgctcg gcatgacccc gcgccaggtg gcgtatcgca ttcagattat ggatatcacc 1560atgccgcgac tgtga 15751451566DNAA. vinelandii 145atgaacgcca cattcgccga acgccccagc gcgccaaccc gcaacgaact gctggatgcc 60caactgcagg cgctggcgca gatcgcccgc atccttaacc gcggccggcc catcgaggaa 120ctgctggccg agatcctcgc cgtgctgcac gaagacctcg gcctgctgca cgggctggtc 180tccatctgca acccgaagga cggcagcctg caggtgggcg ccgtgcacag cgactccgaa 240accgtggtac gggcctgcga aagcacccgc taccgcatcg gcgaaggcgt gttcggcaac 300atcctcaagc atggcaacag cgtggtgctc gggcgtatcg acgccgaacc gcgctttctc 360gaccgactgg cgctgtacga catggacctg cccttcatcg ccgtgccgat caaggccgtc 420gacggcacca ccatcggcgt gctggctgcc cagcccgacc gccgcgccga cgagctgatg 480cccgaacgca cccgtttgat ggaaatcgtc gcccgcctac tggcgcagac cgtgcgcctg 540gtggtgaacc tcgaggacgg ccaggaagtg gtcgacgagc gcgacgagct acgccgcgaa 600gtccgcgcca agtacggctt cgagaacatg gtggtgggcc acaccgcctc catgcgccgg 660gttttcgacc aggttcgacg ggtcgccaag tggaacagca ccgtgctgat cctcggcgaa 720tccggcaccg gcaaggagct gatcgccagc gccatccact acaactcacc gcgcgctcac 780cagccgctgg tacgcctgaa ctgcgccgcg ctaccggaaa ccctgctcga atcggaactg 840ttcggtcacg agaaaggcgc cttcaccggc gccgtgaagc agcgcaaggg acgtttcgaa 900caggccgacg gcggcaccct gttcctcgac gagatcggcg agatctcgcc gatgttccag 960gccaagctgc tgcgcgtgct gcaggaaggc gagctggagc gcgtcggcgg cagccagacg 1020gtgaaggtca acgtgcgcat cgtcgccgcc accaaccgcg acctggagca cgaggtggag 1080caaggcaagt tccgcgaaga cctctactac cgcctcaacg tcatggccat ccgcgtcccg 1140ccgctgcgcg agcgcagcgc cgacatcccg gaactggccg aattcctcct cgacaagatc 1200gcccgccagc agggtcgcaa actcaagctg accgacagcg ccctgcgtct gctgatgagc 1260caccgctggc cgggcaacgt gcgcgaactg gaaaactgcc tggaacgctc ggccatcatg 1320agcgaggatg gcaccatcag ccgcgacgtg gtctccctca ccggcctcga ccacgacgcc 1380acgccgctgg cgccggtccc cgaagtcgac ctcgccgacg acagcctcga cgaccgcgag 1440cgcgtcatcg ccgcgctgga acaggccggc tgggtccagg ccaaggccgc ccgcctgctc 1500ggcatgacgc cccggcagat cgcctaccga gtgcagacgc tgaacattca tatgcgcaag 1560atctga 15661461569DNAUnknownR. sp. IRBG74 146atgaatgcaa ccatccctca gcgctcggcc aaacagaacc cggtcgaact ctatgacctg 60caattgcagg ccctggcgag catcgcccgc acgctcagcc gcgaacaaca gatcgacgaa 120ctgctcgaac aggtcctggc cgtactgcac aatgacctcg gcctgctgca tggcctggtg 180accatttccg acccggaaca cggcgccctg cagatcggcg ccatccacac cgactcggaa 240gcggtggccc aggcctgcga aggcgtgcgc tacagaagcg gcgaaggcgt gatcggcaac 300gtgctcaagc acggcaacag cgtggtgctc gggcgcatct ccgccgaccc gcgctttctc 360gaccgcctgg cgctgtacga cctggaaatg ccgttcatcg ccgtgccgat caagaacccc 420gagggcaaca ccatcggcgt gctggcggcc cagccggact gccgcgccga cgagcacatg 480cccgcgcgca cgcgccttct ggagatcgtc gccaacctgc tggcgcagac cgtgcgcctg 540gtggtgaaca tcgaggacgg ccgcgaggcg gccgacgagc gcgacgaact gcgtcgcgag 600gtgcgcggca agtacggctt cgagaacatg gtggtgggcc acacccccac catgcgccgg 660gtgttcgatc agatccgccg ggtcgccaag tggaacagca ccgtactggt cctcggcgag 720tccggtaccg gcaaggaact gatcgccagc gccatccact acaactcgcc gcgcgcgcac 780cgccccttcg tgcgcctgaa ctgcgccgcg ctgccggaaa ccctgctcga gtccgaactc 840ttcggccacg agaagggcgc cttcaccggc gcggtgaagc agcgcaaggg gcgtttcgag 900caggccgacg gcggcaccct gttcctcgac gagatcggcg agatctcgcc gatgttccag 960gccaagctgc tgcgcgtgct gcaggaaggc gagttcgagc gggtcggcgg caaccagacg 1020gtgcgggtca acgtgcgcat cgtcgccgcc accaaccgcg acctggaaag cgaggtggaa 1080aagggcaagt tccgcgagga cctctactac cgcctgaacg tcatggccat ccgcattccg 1140ccgctgcgcg agcgtaccgc cgacattccc gaactggcgg aattcctgct cggcaagatc 1200ggccgccagc agggccgccc gctgaccgtc accgacagcg ccatccgcct gctgatgagc 1260caccgctggc cgggcaacgt gcgcgaactg gagaactgcc tggagcgctc ggcgatcatg 1320agcgaggacg gcaccatcac ccgcgacgtg gtctcgctga ccggggtcga caacgagagc 1380ccgccgctcg ccgcgccgct gcccgaggtc

aacctggccg acgagaccct ggacgaccgc 1440gaacgggtga tcgccgccct cgaacaggcc ggctgggtgc aggccaaggc cgcgcggctg 1500ctgggcatga cgccgcggca gatcgcctac cgcatccaga ccctcaacat ccacatgcgc 1560aagatctga 15691471695DNAA. caulinodans 147atgctgcaca atgggctcaa tgagggtatg actgaacgat ccgctcaaac catccacaaa 60ccggatttct ggggcagcgg tatctatcgg atatcgaaag ttttgattgg tccagacagt 120ctcgagacga agcttgccaa tgtcattaac gccctctcag taattctccc aatgcggcgc 180ggcgcaatcg tcgttctaaa tgttaaagga gagcccgaga tggttgcaat gctgggccta 240gagcaagcat ctcaaggcgc ccgctccatt ccggcggagg ctgcgataga tagaatcgtc 300gccaaaggcg cgccgctggt cgtaccggac atttgcaagt cggacctgtt ccaggcggag 360ctccaaacca actcgaacgc cacaggccca gccacgttcg ttggcgtccc gatgaaggtc 420gaaaaagaaa cgcttggaac actatggatc gaccgcgcca aagatggcag cactaggatc 480caatttgagg aagaggtgcg cttcctctcc atggtcgcca acctttcggc ccgggccatt 540tggctggatc gccaccagag ccgcgatggt cagccaatcg tgggcgagga aggaactcgc 600aagactagtt caggcgacaa ggaactgccc gaatctgccc gacaaaggcc cacaaaaatc 660gattggattg tcggggaaag ccctgccctc aagcaggtgg ttgaaagcgt caaagtcgtt 720gcaacaacca attctgcggt gcttctcagg ggcgaaagcg gcacgggcaa ggagttcttt 780gcaaaggcca tccacgagct ttcataccgg aaaaagaagc ccttcgtgaa gttgaactgc 840gccgcgctgt ctgcaggcgt tttggaatcg gaattgtttg gacatgaaaa gggcgccttc 900acgggggcca tctctcagcg cgcaggccgc ttcgaactcg cagacggcgg aacgctgctg 960ctcgatgaga tcggcgacat ttcgccgggc ttccaagcga aactgttgcg cgtcttgcag 1020gaaggtgagc ttgagcgagt cggcggcaca aaaacactca aagtggacgt tcgactcata 1080tgcgccacga acaaagacct agaagcggca gtcgcggatg gggagttcag ggccgacctt 1140tattaccgga tcaatgtggt gcccctattt ctgccgcctc tccgggagcg aaatggggat 1200attccacgcc ttgcgagagt tttcctcggc cgattcaaca gggaaaacaa tcgcgatctc 1260gcgttcgcgc cggctgcgct cgagctcttg tcaaaatgca actttcccgg caacgtccga 1320gagcttgaaa actgcgtccg caggaccgcc actctcgcgc gttcggagac gatcgttcca 1380tcagatttct cctgcctgaa gaaccagtgc ttttcttcaa tgctctggaa aaccggtgac 1440cgtccacttg gggatacgct caatgggttg gccatgcgta agagtttgtc ggtcgaatcg 1500ccgatcagcc tcggttactc caatggaccg gccggcttaa cggtggcacc acatctaacg 1560gaccgcgagc tgctaatcag tgcgatggag aaggccggtt gggttcaggc aaaggcagct 1620cggatcctcg gcctcacacc gcgacaggtc ggctatgctt tacgtaggca tcgtatacag 1680gtgaagaaaa tctaa 16951481848DNAArtificial SequenceSynthetic polynucleotide 148atgccaatga ccgacgcctt ccaggtccgc gtacctcggg tttcgtcgag caccgccgga 60gacatcgccg cgtcatccat caccacgcgg ggcgcgctgc cgcgcccggg agggatgcct 120gtgtccatgt cgcgggggac ctcgcccgag gtggcactca tcggggtcta tgagatatcg 180aagatcctga cggcgccccg gcgcctcgaa gtcacgctcg ccaatgtggt gaacgtgctc 240tcctccatgc tgcagatgcg gcatggcatg atctgcatcc tcgacagcga gggcgatccc 300gacatggtgg ccaccaccgg ctggacgcct gagatggcgg gccagatccg cgcgcatgtg 360ccccagaagg ccatcgacca gatcgtcgcc acgcagatgc cgctggtggt gcaggacgtg 420acggccgatc cgctcttcgc cggtcacgag gatctgttcg gcccgcctga ggaggccacc 480gtctccttca tcggcgtgcc gatcaaggcc gaccaccatg tgatgggcac cctctccatc 540gaccgcatct gggacggcac cgcccgtttc cgcttcgacg aggacgtgcg cttcctcacc 600atggtggcca atctcgtcgg ccagaccgtg cgcctgcaca agctggtggc gagcgaccgc 660gaccggctga tcgcccagac gcaccgcctc gaaaaggcgc tgcgggaaga aaaatccggg 720gccgagccgg aggtggccga ggccgccaac ggatccgcca tgggcatcgt gggcgatagc 780ccgctggtga aacgcctgat cgcgaccgcg caagtggtcg cccgctcaaa ctccaccgtg 840ctgctgcgcg gggagagcgg caccggcaag gagttgttcg cccgtgccat ccacgaactg 900tcgccccgca agggcaagcc cttcgtgaag gtgaactgcg ccgccctccc ggaatcggtg 960ctggaatcgg aactgttcgg ccatgagaag ggcgccttca ccggtgcgct gaacatgcgc 1020cagggccgct tcgagctggc gcacggcggc acgctcttcc ttgacgagat cggcgagatc 1080acccccgctt tccaggccaa gctgctgcgc gtgctgcagg aaggcgagtt cgagcgggtc 1140ggcggcaatc gcacgctgaa ggtggatgtg cggctcgtgt gcgccaccaa caagaatctg 1200gaagaggcgg tctccaaggg cgagttccgg gccgatctct actaccgcat ccatgtggtg 1260ccgctgatcc tgccgccgct gcgcgaacgg ccgggcgaca ttcccaagct cgcgaagaac 1320ttcctcgacc gcttcaacaa ggaaaacaag ctccacatga tgctctcggc gccggccatc 1380gacgtgctgc ggcgctgcta tttcccgggc aacgtgcgcg agctggagaa ctgtatccgg 1440cggacggcaa cgctcgccca cgatgccgtc atcacccccc atgacttcgc ctgcgacagc 1500ggccagtgcc tctcggccat gctctggaag ggctcggccc cgaagcctgt gatgccgcac 1560gtgccgccgg cgcccacgcc gctgactccg ctctcccctg ctccgctcgc gaccgcagcg 1620cccgctgcgg cgagcccggc gccggcggcc gacagcctgc cggtcacttg ccccggcacc 1680gaggcctgtc ccgcggtgcc cccccgccag agcgaaaagg agcagttgct ccaggccatg 1740gagcgctccg gctgggtgca ggcgaaggcc gcgcgcctcc tcaacctcac gccgcgccag 1800gtgggttatg cgctgcgcaa atatgacatc gacatcaagc gcttctga 184814947DNAArtificial SequenceSynthetic polynucleotide 149taggtgttga cggctagctc agtcctaggt acagtgctag ctctaga 4715047DNAArtificial SequenceSynthetic polynucleotide 150taggtgttta cagctagctc agtcctaggt attatgctag ctctaga 4715147DNAArtificial SequenceSynthetic polynucleotide 151taggtgttga cagctagctc agtcctaggt actgtgctag ctctaga 4715247DNAArtificial SequenceSynthetic polynucleotide 152taggtgctga tagctagctc agtcctaggg attatgctag ctctaga 4715347DNAArtificial SequenceSynthetic polynucleotide 153taggtgttga cagctagctc agtcctaggt attgtgctag ctctaga 4715447DNAArtificial SequenceSynthetic polynucleotide 154taggtgttta cggctagctc agtcctaggt actatgctag ctctaga 4715547DNAArtificial SequenceSynthetic polynucleotide 155taggtgttta cggctagctc agtcctaggt atagtgctag ctctaga 4715647DNAArtificial SequenceSynthetic polynucleotide 156taggtgttta cggctagctc agccctaggt attatgctag ctctaga 4715747DNAArtificial SequenceSynthetic polynucleotide 157taggtgctga cagctagctc agtcctaggt ataatgctag ctctaga 4715847DNAArtificial SequenceSynthetic polynucleotide 158taggtgttta cagctagctc agtcctaggg actgtgctag ctctaga 4715947DNAArtificial SequenceSynthetic polynucleotide 159taggtgttta cggctagctc agtcctaggt acaatgctag ctctaga 4716047DNAArtificial SequenceSynthetic polynucleotide 160taggtgttga cggctagctc agtcctaggt atagtgctag ctctaga 4716147DNAArtificial SequenceSynthetic polynucleotide 161taggtgctga tagctagctc agtcctaggg attatgctag ctctaga 4716247DNAArtificial SequenceSynthetic polynucleotide 162taggtgctga tggctagctc agtcctaggg attatgctag ctctaga 4716347DNAArtificial SequenceSynthetic polynucleotide 163taggtgttta tggctagctc agtcctaggt acaatgctag ctctaga 4716447DNAArtificial SequenceSynthetic polynucleotide 164taggtgttta tagctagctc agcccttggt acaatgctag ctctaga 4716547DNAArtificial SequenceSynthetic polynucleotide 165taggtgttga cagctagctc agtcctaggg actatgctag ctctaga 4716647DNAArtificial SequenceSynthetic polynucleotide 166taggtgttga cagctagctc agtcctaggg attgtgctag ctctaga 4716747DNAArtificial SequenceSynthetic polynucleotide 167taggtgttga cggctagctc agtcctaggt attgtgctag ctctaga 4716847DNAArtificial SequenceSynthetic polynucleotide 168taggtgttga cagctagctc agtcctaggt ataatgctag ctctaga 4716947DNAArtificial SequenceSynthetic polynucleotide 169taggtgttga cattattcca tcgaactagt taactagtac gaaagtt 4717048DNAArtificial SequenceSynthetic polynucleotide 170tagcataacc ccttggggcc tctaaacggg tcttgagggg ttttttgt 4817148DNAArtificial SequenceSynthetic polynucleotide 171tactcgaacc cctagcccgc tcttatcggg cggctagggg ttttttgt 4817229DNAArtificial SequenceSynthetic polynucleotide 172tacatatcgg gggggtaggg gttttttgt 2917380DNAArtificial SequenceSynthetic polynucleotide 173ccaggcatca aataaaacga aaggctcagt cgaaagactg ggcctttcgt tttatctgtt 60gtttgtcggt gaacgctctc 8017461DNAArtificial SequenceSynthetic polynucleotide 174ctcggtacca aattccagaa aagaggcctc ccgaaagggg ggcctttttt cgttttggtc 60c 61175146DNAArtificial SequenceSynthetic polynucleotide 175ctcggtacca aattccagaa aagacacccg aaagggtgtt ttttcgtttt ggtcctcctt 60ggccctccat ccttagatag cagataaaaa aaatccttag ctttcgctaa ggatgatttc 120ttcataggca atacgatcgc atgtcc 146176129DNAArtificial SequenceSynthetic polynucleotide 176ccaggcatca aataaaacga aaggctcagt cgaaagactg ggcctttcgt tttatctgtt 60gtttgtcggt gaacgctctc tactagagtc acactggctc accttcgggt gggcctttct 120gcgtttata 129177129DNAArtificial SequenceSynthetic polynucleotide 177ccaggcatca aataaaacga aaggctcagt cgaaagactg ggcctttcgt tttatctgtt 60gtttgtcggt gaacgctctc tactagagtc acactggctc accttcgggt gggcctttct 120gcgtttata 129178168DNAArtificial SequenceSynthetic polynucleotide 178ggtcttgtcc actaccttgc agtaatgcgg tggacaggat cggcggtttt cttttctctt 60ctcaatgact gaatagaaaa gacgaacatt aacgcatgag aaagcccccg gaagatcacc 120ttccgggggc ttttttattg cgctacaaat gaaagtacat agaaatta 168179146DNAArtificial SequenceSynthetic polynucleotide 179cagataaaaa aaatccttag ctttcgctaa ggatgatttc ttccttggcc ctccatcctt 60agatagctcg gtaccaaatt ccagaaaaga cacccgaaag ggtgtttttt cgttttggtc 120ctcataggca atacgatcgc atgtcc 146180128DNAArtificial SequenceSynthetic polynucleotide 180ccaggcatca aataaaacga aaggctcagt cgaaagactg ggcctttcgt tttatctgtt 60gtttgtcggt gaacgctctc ctagcataac cccttggggc ctctaaacgg gtcttgaggg 120gttttttg 128181152DNAArtificial SequenceSynthetic polynucleotide 181ctcggtacca aattccagaa aagagacgct ttcgagcgtc ttttttcgtt ttggtcctcc 60ttggccctcc atccttagat agagttaacc aaaaaggggg gattttatct cccctttaat 120ttttccttca taggcaatac gatcgcatgt cc 152182144DNAArtificial SequenceSynthetic polynucleotide 182cgcagatagc aaaaaagcgc ctttagggcg cttttttaca ttggtggtcc ttggccctcc 60atccttagat agaggcgact gacgaaacct cgctccggcg gggttttttg ttatctgcat 120cataggcaat acgatcgcat gtcc 14418382DNAArtificial SequenceSynthetic polynucleotide 183tcggtcagtt tcacctgatt tacgtaaaaa cccgcttcgg cgggtttttg cttttggagg 60ggcagaaaga tgaatgactg tc 82184103DNAArtificial SequenceSynthetic polynucleotide 184gcccccggaa gatcaccttc cgggggcttt tttattggcg gccggctgat tgatcaggcg 60gccggctgat tggcgcgtta cctggtagcg cgccattttg ttt 10318583DNAArtificial SequenceSynthetic polynucleotide 185gtaatcgtta atccgcaaat aacgtaaaaa cccgcttcgg cgggtttttt tatgggggga 60gtttagggaa agagcatttg tca 8318641DNAArtificial SequenceSynthetic polynucleotide 186aaaaaaaaac cccgcccctg acagggcggg gttttttttt t 41187152DNAArtificial SequenceSynthetic polynucleotide 187tccggcaatt aaaaaagcgg ctaaccacgc cgcttttttt acgtctgcat gactgaatag 60aaaagacgaa cattaacgca tgagaaagcc cccggaagat caccttccgg gggctttttt 120attgcgctcc ttggccctcc atccttagat ag 152188167DNAArtificial SequenceSynthetic polynucleotide 188ggaagaccat actggaaaca cagaaaaaag cccgcacctg acagtgcggg cttttttttt 60cgaccaaagg tgactgaata gaaaagacga acattcgcag atagcaaaaa agcgccttta 120gggcgctttt ttacattggt ggtcataggc aatacgatcg catgtcc 167189160DNAArtificial SequenceSynthetic polynucleotide 189tccggcaatt aaaaaagcgg ctaaccacgc cgcttttttt acgtctgcat ccttggccct 60ccatccttag atagctcggt accaaattcc agaaaagagg cctcccgaaa ggggggcctt 120ttttcgtttt ggtcctcata ggcaatacga tcgcatgtcc 160190199DNAArtificial SequenceSynthetic polynucleotide 190ttcagccaaa aaacttaaga ccgccggtct tgtccactac cttgcagtaa tgcggtggac 60aggatcggcg gttttctttt ctcttctcaa tacatgaaag tacatagaaa ttactcggta 120ccaaattcca gaaaagaggc ctcccgaaag gggggccttt tttcgttttg gtcctcatag 180gcaatacgat cgcatgtcc 199191189DNAArtificial SequenceSynthetic polynucleotide 191ttcagccaaa aaacttaaga ccgccggtct tgtccactac cttgcagtaa tgcggtggac 60aggatcggcg gttttctttt ctcttctcaa tccttggccc tccatcctta gatagtccgg 120caattaaaaa agcggctaac cacgccgctt tttttacgtc tgcatcatag gcaatacgat 180cgcatgtcc 189192164DNAArtificial SequenceSynthetic polynucleotide 192ctcggtacca aattccagaa aagaggcctc ccgaaagggg ggcctttttt cgttttggtc 60ctgactgaat agaaaagacg aacattaacg catgagaaag cccccggaag atcaccttcc 120gggggctttt ttattgcgct ccttggccct ccatccttag atag 164193159DNAArtificial SequenceSynthetic polynucleotide 193ctcggtacca aattccagaa aagaggcctc ccgaaagggg ggcctttttt cgttttggtc 60ctccttggcc ctccatcctt agatgtccgg caattaaaaa agcggctaac cacgccgctt 120tttttacgtc tgcatcatag gcaatacgat cgcatgtcc 159194197DNAArtificial SequenceSynthetic polynucleotide 194ctcggtacca aagacgaaca ataagacgct gaaaagcgtc ttttttcgtt ttggtcctac 60aaatgaaagt acatagaaat tattcagcca aaaaacttaa gaccgccggt cttgtccact 120accttgcagt aatgcggtgg acaggatcgg cggttttctt ttctcttctc aatccttggc 180cctccatcct tagatag 197195121DNAArtificial SequenceSynthetic polynucleotide 195gggaactgcc agacatcaaa taaaacaaaa ggctcagtcg gaagactggg ccttttgttt 60tatctgttgt ttgtcggtga acactctccc gactagtagc ggccgctgca gaaagaggag 120a 121196152DNAArtificial SequenceSynthetic polynucleotide 196aacgcatgag aaagcccccg gaagatcacc ttccgggggc ttttttattg cgctcatagg 60caatacgatc gcatgtcctc cggcaattaa aaaagcggct aaccacgccg ctttttttac 120gtctgcatcc ttggccctcc atccttagat ag 15219791DNAArtificial SequenceSynthetic polynucleotide 197gggaactgcc agacatcaaa taaaacaaaa ggctcagtcg gaagactggg ccttttgttt 60tatctgttgt ttgtcggtga acactctccc g 91198195DNAArtificial SequenceSynthetic polynucleotide 198aaagcaagct gataaaccga tacaattaaa ggctcctttt ggagcctttt tttttggaga 60ttttcaacat gaaaaaatta ttatttgatg atcagatagc ggcggggaac tgccagacat 120caaataaaac aaaaggctca gtcggaagac tgggcctttt gttttatctg ttgtttgtcg 180gtgaacactc tcccg 195199164DNAArtificial SequenceSynthetic polynucleotide 199aacgcatgag aaagcccccg gaagatcacc ttccgggggc ttttttattg cgctccttgg 60ccctccatcc ttagatagct cggtaccaaa ttccagaaaa gaggcctccc gaaagggggg 120ccttttttcg ttttggtcct cataggcaat acgatcgcat gtcc 164200193DNAArtificial SequenceSynthetic polynucleotide 200aacgcatgag aaagcccccg gaagatcacc ttccgggggc ttttttattg cgctccttgg 60ccctccatcc ttagatagtt cagccaaaaa acttaagacc gccggtcttg tccactacct 120tgcagtaatg cggtggacag gatcggcggt tttcttttct cttctcaatc ataggcaata 180cgatcgcatg tcc 19320167DNAArtificial SequenceSynthetic polynucleotide 201cctaggacct gtaggatcgt acaggtttac gcaagaaaat ggtttgttac tttcgaataa 60atctaga 6720268DNAArtificial SequenceSynthetic polynucleotide 202cggtggaatc cctatcagtg atagagattg acatccctat cagtgataga tataatgagc 60actctaga 6820390DNAArtificial SequenceSynthetic polynucleotide 203aacaaacaga caatctggtc tgtttgtatt atggaaaatt tttctgtata atagattcaa 60caaacagaca atctggtctg tttgtattat 9020458DNAArtificial SequenceSynthetic polynucleotide 204aaaaagagtt tgacatgata cgaaacgtac cgtatcgtta aggttactag agtctaga 58205116DNAArtificial SequenceSynthetic polynucleotide 205ggggcctcgc ttgggttatt gctggtgccc ggccgggcgc aatattcatg ttgatgattt 60attatatatc gagtggtgta tttatttata ttgtttgctc cgttaccgtt attaac 116206753DNAArtificial SequenceSynthetic polynucleotide 206atgaaaaaca taaatgccga cgacacatac agaataatta ataaaattaa agcttgtaga 60agcaataatg atattaatca atgcttatct gatatgacta aaatggtaca ttgtgaatat 120tatttactcg cgatcattta tcctcattct atggttaaat ctgatatttc aatcctagat 180aattacccta aaaaatggag gcaatattat gatgacgcta atttaataaa atatgatcct 240atagtagatt attctaactc caatcattca ccaattaatt ggaatatatt tgaaaacaat 300gctgtaaata aaaaatctcc aaatgtaatt aaagaagcga aaacatcagg tcttatcact 360gggtttagtt tccctattca tacggctaac aatggcttcg gaatgcttag ttttgcacat 420tcagaaaaag acaactatat agatagttta tttttacatg cgtgtatgaa cataccatta 480attgttcctt ctctagttga taattatcga aaaataaata tagcaaataa taaatcaaac 540aacgatttaa ccaaaagaga aaaagaatgt ttagcgtggg catgcgaagg aaaaagctct 600tgggatattt caaaaatatt aggttgcagt gagcgtactg tcactttcca tttaaccaat 660gcgcaaatga aactcaatac aacaaaccgc tgccaaagta tttctaaagc aattttaaca 720ggagcaattg attgcccata ctttaaaaat taa 753207624DNAArtificial SequenceSynthetic polynucleotide 207atgtccagat

tagataaaag taaagtgatt aacagcgcat tagagctgct taatgaggtc 60ggaatcgaag gtttaacaac ccgtaaactc gcccagaagc taggtgtaga gcagcctaca 120ttgtattggc atgtaaaaaa taagcgggct ttgctcgacg ccttagccat tgagatgtta 180gataggcacc atactcactt ttgcccttta gaaggggaaa gctggcaaga ttttttacgt 240aataacgcta aaagttttag atgtgcttta ctaagtcatc gcgatggagc aaaagtacat 300ttaggtacac ggcctacaga aaaacagtat gaaactctcg aaaatcaatt agccttttta 360tgccaacaag gtttttcact agagaatgca ttatatgcac tcagcgctgt ggggcatttt 420actttaggtt gcgtattgga agatcaagag catcaagtcg ctaaagaaga aagggaaaca 480cctactactg atagtatgcc gccattatta cgacaagcta tcgaattatt tgatcaccaa 540ggtgcagagc cagccttctt attcggcctt gaattgatca tatgcggatt agaaaaacaa 600cttaaatgtg aaagtgggtc ctaa 624208612DNAArtificial SequenceSynthetic polynucleotide 208atgagcccga aacgtcgtac ccaggcagaa cgtgcaatgg aaacccaggg taaactgatt 60gcagcagcac tgggtgttct gcgtgaaaaa ggttatgcag gttttcgtat tgcagatgtt 120ccgggtgcag ccggtgttag ccgtggtgca cagagccatc attttccgac caaactggaa 180ctgctgctgg caacctttga atggctgtat gagcagatta ccgaacgtag ccgtgcacgt 240ctggcaaaac tgaaaccgga agatgatgtt attcagcaga tgctggatga tgcagcagaa 300ttttttctgg atgatgattt tagcatcagc ctggatctga ttgttgcagc agatcgtgat 360ccggcactgc gtgaaggtat tcagcgtacc gttgaacgta atcgttttgt tgttgaagat 420atgtggctgg gtgtgctggt gagccgtggt ctgagccgtg atgatgccga agatattctg 480tggctgattt ttaacagcgt tcgtggtctg gcagttcgta gcctgtggca gaaagataaa 540gaacgttttg aacgtgtgcg taatagcacc ctggaaattg cacgtgaacg ttatgcaaaa 600ttcaaacgtt ga 612209603DNAArtificial SequenceSynthetic polynucleotide 209atggcacgta ccccgagccg tagcagcatt ggtagcctgc gtagtccgca tacccataaa 60gcaattctga ccagcaccat tgaaatcctg aaagaatgtg gttatagcgg tctgagcatt 120gaaagcgttg cacgtcgtgc cggtgcaagc aaaccgacca tttatcgttg gtggaccaat 180aaagcagcac tgattgccga agtgtatgaa aatgaaagcg aacaggtgcg taaatttccg 240gatctgggta gctttaaagc cgatctggat tttctgctgc gtaatctgtg gaaagtttgg 300cgtgaaacca tttgtggtga agcatttcgt tgtgttattg cagaagcaca gctggaccct 360gcaaccctga cccagctgaa agatcagttt atggaacgtc gtcgtgagat gccgaaaaaa 420ctggttgaaa atgccattag caatggtgaa ctgccgaaag ataccaatcg tgaactgctg 480ctggatatga tttttggttt ttgttggtat cgcctgctga ccgaacagct gaccgttgaa 540caggatattg aagaatttac cttcctgctg attaatggtg tttgtccggg tacacagcgt 600taa 603210906DNAArtificial SequenceSynthetic polynucleotide 210atggaactgc gtgacctgga tttaaacctg ctggtggtgt tcaaccagtt gctggtcgac 60agacgcgtct ctgtcactgc ggagaacctg ggcctgaccc agcctgccgt gagcaatgcg 120ctgaaacgcc tgcgcacctc gctacaggac ccactcttcg tgcgcacaca tcagggaatg 180gaacccacac cctatgccgc gcatctggcc gagcacgtca cttcggccat gcacgcactg 240cgcaacgccc tacagcacca tgaaagcttc gatccgctga ccagcgagcg taccttcacc 300ctggccatga ccgacattgg cgagatctac ttcatgccgc ggctgatgga tgcgctggct 360caccaggccc ccaattgcgt gatcagtacg gtgcgcgaca gttcgatgag cctgatgcag 420gccttgcaga acggaaccgt ggacttggcc gtgggcctgc ttcccaatct gcaaactggc 480ttctttcagc gccggctgct ccagaatcac tacgtgtgcc tatgtcgcaa ggaccatcca 540gtcacccgcg aacccctgac tctggagcgc ttctgttcct acggccacgt gcgtgtcatc 600gccgctggca ccggccacgg cgaggtggac acgtacatga cacgggtcgg catccggcgc 660gacatccgtc tggaagtgcc gcacttcgcc gccgttggcc acatcctcca gcgcaccgat 720ctgctcgcca ctgtgccgat atgtttagcc gactgctgcg tagagccctt cggcctaagc 780gccttgccgc acccagtcgt cttgcctgaa atagccatca acatgttctg gcatgcgaag 840taccacaagg acctagccaa tatttggttg cggcaactga tgtttgacct gtttacggat 900tgataa 90621190DNAArtificial SequenceSynthetic polynucleotide 211tcaatgtatt gatgccgtcc atatcatgaa tcaaaacaat ccatttgatc aatatcaagc 60tcactcttaa gcttcactca tccgctgcat 90212930DNAArtificial SequenceSynthetic polynucleotide 212atgcgtttca acaagctcga cctcaatctt ctggtcgccc tggatgcact gctcacggag 60atgagcatca gccgcgccgc cgaaaagatc catctgagcc agtcggccat gagcaatgcc 120ctggcgcggc tgcgcgagta tttcgatgat gaattgctga tccaggtggg ccggcgcatg 180gagcccacgc cgcgcgccga ggtgctcaag gatgcggtgc atgatgtgct gcggcgtatc 240gatggctcca tcgcggcgct gccggccttc gtgccggccg agtccacgcg cgagtttcgc 300atctcggttt cggactttac gctctccgtc ctcatccccc gggtgctggc gcgcgcgcac 360gccgagggca agcacatccg ctttgccctg atgccgcagg tgcaagaccc gacccgctcg 420ctggatcggg ccgaggtgga cctgctggtc ttgccgcagg aattctgcac gcccgatcat 480cctgccgaag aggtcttccg cgaacggcat gtctgcgtgg tctggcgcga cagtgcgctg 540gcgcaaggcg agctgacgct ggaacgctac atggcctcag gccatgtggt gatggtgccg 600cctggggcca atgcgtcgtc ggtggaggcg tggatggcca ggaagctggg ctttgcgcgc 660cgggtggaag tgaccagctt cagcttcgct tctgcgctgg cgctggtaca ggggacggac 720cgcatcgcca cggtgcatgc ccggctggcg cagctgctgg ctccgcaatg gccggtggtg 780atcaaggaga gtccgctgtc gctgggcgag atgcggcaga tgatgcagtg gcatcgctac 840cgcagcaatg atcctggcat ccagtggctg cgtcgggtgt ttctggagag tgcgcaggag 900atggatgcgg cgctgccagg catctgctga 930213286DNAArtificial SequenceSynthetic polynucleotide 213cagacattgc cgtcactgcg tcttttactg gctcttctcg ctaaccaaac cggtaacccc 60gcttattaaa agcattctgt aacaaagcgg gaccaaagcc atgacaaaaa cgcgtaacaa 120aagtgtctat aatcacggca gaaaagtcca cattgattat ttgcacggcg tcacactttg 180ctatgccata gcatttttat ccataagatt agcggatcct acctgacgct ttttatcgca 240actctctata ttttctccat acccgttttt ttgggctagc gaattc 286214930DNAArtificial SequenceSynthetic polynucleotide 214atgcaatatg gacaattggt ttcttctctg aatggcggga gtatgaaaag tatggctgaa 60gcgcaaaatg atcccctgct gccgggatac tcgtttaatg cccatctggt ggcgggttta 120acgccgattg aggccaacgg ttatctcgat ttttttatcg accgaccgct gggaatgaaa 180ggttatattc tcaatctcac cattcgcggt cagggggtgg tgaaaaatca gggacgagaa 240tttgtttgcc gaccgggtga tattttgctg ttcccgccag gagagattca tcactacggt 300cgtcatccgg aggctcgcga atggtatcac cagtgggttt actttcgtcc gcgcgcctac 360tggcatgaat ggcttaactg gccgtcaata tttgccaata cggggttctt tcgcccggat 420gaagcgcacc agccgcattt cagcgacctg tttgggcaaa tcattaacgc cgggcaaggg 480gaagggcgct attcggagct gctggcgata aatctgcttg agcaattgtt actgcggcgc 540atggaagcga ttaacgagtc gctccatcca ccgatggata atcgggtacg cgaggcttgt 600cagtacatca gcgatcacct ggcagacagc aattttgata tcgccagcgt cgcacagcat 660gtttgcttgt cgccgtcgcg tctgtcacat cttttccgcc agcagttagg gattagcgtc 720ttaagctggc gcgaggacca acgtatcagc caggcgaagc tgcttttgag caccacccgg 780atgcctatcg ccaccgtcgg tcgcaatgtt ggttttgacg atcaactcta tttctcgcgg 840gtatttaaaa aatgcaccgg ggccagcccg agcgagttcc gtgccggttg tgaagaaaaa 900gtgaatgatg tagccgtcaa gttgtcataa 9302151419DNAArtificial SequenceSynthetic polynucleotide 215atggttacta tcaatacgga atctgcttta acgccacgtt ctttgcggga tacgcggcgt 60atgaatatgt ttgtttcggt agctgctgcg gtcgcaggat tgttatttgg tcttgatatc 120ggcgtaatcg ccggagcgtt gccgttcatt accgatcact ttgtgctgac cagtcgtttg 180caggaatggg tggttagtag catgatgctc ggtgcagcaa ttggtgcgct gtttaatggt 240tggctgtcgt tccgcctggg gcgtaaatac agcctgatgg cgggggccat cctgtttgta 300ctcggttcta tagggtccgc ttttgcgacc agcgtagaga tgttaatcgc cgctcgtgtg 360gtgctgggca ttgctgtcgg gatcgcgtct tacaccgctc ctctgtatct ttctgaaatg 420gcaagtgaaa acgttcgcgg taagatgatc agtatgtacc agttgatggt cacactcggc 480atcgtgctgg cgtttttatc cgatacagcg ttcagttata gcggtaactg gcgcgcaatg 540ttgggggttc ttgctttacc agcagttctg ctgattattc tggtagtctt cctgccaaat 600agcccgcgct ggctggcgga aaaggggcgt catattgagg cggaagaagt attgcgtatg 660ctgcgcgata cgtcggaaaa agcgcgagaa gaactcaacg aaattcgtga aagcctgaag 720ttaaaacagg gcggttgggc actgtttaag atcaaccgta acgtccgtcg tgctgtgttt 780ctcggtatgt tgttgcaggc gatgcagcag tttaccggta tgaacatcat catgtactac 840gcgccgcgta tcttcaaaat ggcgggcttt acgaccacag aacaacagat gattgcgact 900ctggtcgtag ggctgacctt tatgttcgcc acctttattg cggtgtttac ggtagataaa 960gcagggcgta aaccggctct gaaaattggt ttcagcgtga tggcgttagg cactctggtg 1020ctgggctatt gcctgatgca gtttgataac ggtacggctt ccagtggctt gtcctggctc 1080tctgttggca tgacgatgat gtgtattgcc ggttatgcga tgagcgccgc gccagtggtg 1140tggatcctgt gctctgaaat tcagccgctg aaatgccgcg atttcggtat tacctgttcg 1200accaccacga actgggtgtc gaatatgatt atcggcgcga ccttcctgac actgcttgat 1260agcattggcg ctgccggtac gttctggctc tacactgcgc tgaacattgc gtttgtgggc 1320attactttct ggctcattcc ggaaaccaaa aatgtcacgc tggaacatat cgaacgcaaa 1380ctgatggcag gcgagaagtt gagaaatatc ggcgtctga 141921675DNAArtificial SequenceSynthetic polynucleotide 216ctcgagtgtt gacaattaat catcggctcg tataatgtgt ggaattgtga gcgctcacaa 60tttcacacat ctaga 75217221DNAArtificial SequenceSynthetic polynucleotide 217aacaaataca catgggcgca tgcctattac tgcccttgcg atatggaagg caagctttta 60gtaacaatag aaaactgggt cctactctcg aagaatgcac tgcggcggtc acgtcaacac 120gtgctgcacc gttgagaatg aatgctgggc agattgccag cggcgtcatt ttcggctgtc 180ccgtcctcac ggttttgcgc tgcatcgcaa gagattggga a 221218849DNAArtificial SequenceSynthetic polynucleotide 218atgacgtcag cagcgaatct ggtgaggatc acgcagcccg cgatcagccg gctgatcagg 60gatctcgaag aggaaattgg gatcagcctc ttcgaaagaa cgggcaaccg gttacgtcct 120acgcgggagg ccggtattct gttcaaggaa gtgtcgcgac atttcaacgg gattcagcac 180atcgacaaag tcgcggctga actgaagaag tctcatatgg ggtccctaag ggtcgcctgt 240tatacagcgc cagctctgag ttttatgtcc ggcgtcattc agacgttcat cgccgatcgg 300cccgacgtgt cggtctacct cgacacagtt ccttcccaga cggtcctcga attggtctcg 360ctccagcact acgatctcgg aatatcgata ttggctggcg actatcctgg tctcaccacc 420gaacctgtcc cttcctttcg tgcggtctgc ctgctgccgc cggggcatcg tctcgaagac 480aaggaaactg ttcatgcgac ggaccttgaa ggagagtcat tgatttgcct ctctccagtg 540agccttctac ggatgcaaac ggacgccgca ctggacagct gcggcgtcca ctgtaatcgc 600aggatagaaa gtagtctggc gctgaatctc tgcgatctgg taagcagggg aatgggggtt 660ggtatcgtcg accccttcac tgccgactac tacagtgcaa atccggttat tcagcgctcc 720tttgatccgg ttgtccccta ccattttgct atagttcttc cgaccgacag cccaccgccg 780cgcttggtta gcgagttccg ggcagcgttg cttgatgctt tgaaagcctt gccctatgaa 840accatttga 849219119DNAArtificial SequenceSynthetic polynucleotide 219aaacgcacca taacatctgc ttattcttgc ccggtcatta tgaatttgac cgaatgcata 60tcgaatgtaa agctcaccct ataaatcaca actcttccgg gccaaccggg atcagacgt 119220897DNAArtificial SequenceSynthetic polynucleotide 220atgaatctca ggcaggtcga ggcgttccgg gcagtcatgc tgacggggca aatgacggcg 60gcggctgaac taatgctggt gactcagccg gccatcagtc gcctaatcaa ggactttgaa 120caggcgacaa aactgcagct cttcgagagg cgtgggaacc atattatccc gacacaggag 180gcaaagacgc tgtggaaaga ggtcgatcgg gcgttcgtcg ggcttaatca tataggcaac 240ctggctgccg acatcggcag gcaggcagcg gggacgctcc gcattgctgc aatgcctgct 300ctggcaaacg gcctcttgcc gcggtttctt gctcagttca tccgtgacag accaaatctc 360caggtctccc taatgggact gccctcaagc atggtcatgg aagccgttgc gtccggcagg 420gccgacatcg gttatgccga tggcccacag gagcgccaag gttttctaat cgaaacccgg 480tcgcttcccg ctgttgtcgc tgtcccgatg ggacatcgac ttgctggcct tgaccgtgtc 540acgccacagg accttgccgg tgagcgtatt ataaaacagg agactggcac tctcttcgcc 600atgcgggtag aggtggcgat tggtggtatt caacgccggc cgtcaattga agtgagcctg 660tcgcatactg cgctaagtct cgtccgcgaa ggcgccggga tcgcaattat cgatccagcc 720gcggcgatcg agttcacgga caggatcgta ctgcgaccgt tctcgatctt cattgacgcc 780ggattcctcg aagtccggtc agcaattggc gctccctcaa ccatcgtcga tcgtttcaca 840accgaattct ggaggtttca tgatgacttg atgaagcaga acggcctaat ggagtaa 89722163DNAArtificial SequenceSynthetic polynucleotide 221agcgcgggtg agagggattc gttaccaata gacaattgat tggacgttca atataatgct 60agc 63222226DNAArtificial SequenceSynthetic polynucleotide 222ccctttgtgc gtccaaacgg acgcacggcg ctctaaagcg ggtcgcgatc tttcagattc 60gctcctcgcg ctttcagtct ttgttttggc gcatgtcgtt atcgcaaaac cgctgcacac 120ttttgcgcga catgctctga tccccctcat ctgggggggc ctatctgagg gaatttccga 180tccggctcgc ctgaaccatt ctgctttcca cgaacttgaa aacgct 22622393DNAArtificial SequenceSynthetic polynucleotide 223ttttgttcga ttatcgaaca aattattgaa atatcgaaca aaacctctaa actactgtgg 60cactgaatca aaaaattata aaccctgatc aga 9322451DNAArtificial SequenceSynthetic polynucleotide 224cacccagcag tatttacaaa caaccatgaa tgtaagtata ttccttagca a 5122550DNAArtificial SequenceSynthetic polynucleotide 225attggatcca attgacagct agctcagtcc taggtaccat tggatccaat 5022654DNAUnknownR. sp. IRBG74 226atttcacaca tctagagcta atcatctcgt actaaagagg agaaattaac catg 5422749DNAUnknownR. sp. IRBG74 227atttcacaca tctagagcta atcatcgcgt actcaggagg caagtaatg 4922840DNAUnknownR. sp. IRBG74 228atttcacaca tctagaatta aagaggagaa attaaccatg 4022954DNAUnknownR. sp. IRBG74 229taacaatttc acacatctag agctaatcat ctcgtactaa agaggcaagt aatg 5423054DNAUnknownR. sp. IRBG74 230taacaatttc acacatctag agctaatcat cgcgtactaa ggaggcaagt aatg 5423154DNAUnknownR. sp. IRBG74 231taacaatttc acacatctag agctaatcat cgcgtactca agaggcaagt aatg 5423254DNAUnknownR. sp. IRBG74 232taacaatttc acacatctag agctaatctt cgcgtactaa agaggcaagt aatg 5423354DNAUnknownR. sp. IRBG74 233taacaatttc acacatctag agctaatcat ctcgtactca ggaggcaagt aatg 5423454DNAUnknownR. sp. IRBG74 234taacaatttc acacatctag agctaatcat ctcgtactaa tgaggcaagt aatg 5423554DNAUnknownR. sp. IRBG74 235taacaatttc acacatctag agctaatcat cgcgtactaa tgaggcaagt aatg 5423654DNAUnknownR. sp. IRBG74 236taacaatttc acacatctag agctaatcat cgcgtactca cgaggcaagt aatg 5423754DNAUnknownR. sp. IRBG74 237taacaatttc acacatctag agctaatcat cgcgtactaa aaaggcaagt aatg 5423854DNAUnknownR. sp. IRBG74 238taacaatttc acacatctag agctaatctt cgcgtactaa aaaggcaagt aatg 5423954DNAUnknownR. sp. IRBG74 239taacaatttc acacatctag agctaatctt cgcgtactaa gaaggcaagt aatg 5424054DNAUnknownR. sp. IRBG74 240taacaatttc acacatctag agctaatcat ctcgtactaa ataggcaagt aatg 5424154DNAUnknownR. sp. IRBG74 241taacaatttc acacatctag agctaatcat ctcgtactaa taaggcaagt aatg 5424254DNAUnknownR. sp. IRBG74 242taacaatttc acacatctag agctaatctt ctcgtactaa agaggcaagt aatg 5424354DNAUnknownR. sp. IRBG74 243taacaatttc acacatctag agctaatcat cgcgtactca ataggccagt aatg 5424454DNAUnknownR. sp. IRBG74 244taacaatttc acacatctag agctaatcat cgcgtactaa gtaggcaagt aatg 5424554DNAUnknownR. sp. IRBG74 245taacaatttc acacatctag agctaatcat ctcgtactaa cgaggcaagt aatg 5424654DNAUnknownR. sp. IRBG74 246taacaatttc acacatctag agctaatcat cgcgtactca gcaggcaagt aatg 5424754DNAUnknownR. sp. IRBG74 247taacaatttc acacatctag agctaatctt cgcgtactaa gtaggcaagt aatg 5424854DNAUnknownR. sp. IRBG74 248taacaatttc acacatctag agctaatctt cgcgtactaa ttaggcaagt aatg 5424954DNAUnknownR. sp. IRBG74 249taacaatttc acacatctag agctaatctt ctcgtactaa caaggcaagt aatg 5425054DNAUnknownR. sp. IRBG74 250taacaatttc acacatctag agctaatcat ctcgtactca ataggcaagt aatg 5425154DNAUnknownR. sp. IRBG74 251taacaatttc acacatctag agctaatcat ctcgtactaa gcacgcaagt aatg 5425254DNAUnknownR. sp. IRBG74 252taacaatttc acacatctag agctaatcat cgcgtactaa ctacgcaagt aatg 5425354DNAUnknownR. sp. IRBG74 253taacaatttc acacatctag agctaatctt cgcgtactaa gaacgcaagt aatg 5425454DNAUnknownR. sp. IRBG74 254taacaatttc acacatctag agctaatctt cgcgtactaa aaacgcaagt aatg 5425554DNAUnknownR. sp. IRBG74 255taacaatttc acacatctag agctaatctt cgcgtactaa caacgcaagt aatg 5425654DNAUnknownR. sp. IRBG74 256taacaatttc acacatctag agctaatctt ctcgtactca tgacgcaagt aatg 5425740DNAUnknownR. sp. IRBG74 257atttcacaca tctagaatta aagagaagaa attaaccatg 4025829DNAUnknownR. sp. IRBG74 258ctagtgcgaa ctagctcata ccgcagatg 2925942DNAP. protegens 259ctagcgcagg tccaacgttt ttctaagcaa ggaggtcata tg 4226042DNAP. protegens 260ctagcgaagg tccaacgttt ttctaagcaa ggaggtcata tg 4226142DNAP. protegens 261ctagcgaagg tccaacgttt ttctaagcca ggaggtcata tg 4226242DNAP. protegens 262ctagcgcagg tccaacgttt ttctaagcca ggaggtcata tg 4226342DNAP. protegens 263ctagcgaagc tccaacgttt ttctaagcaa ggaggtcata tg 4226433DNAP. protegens 264gaattctaca ctaacggaca ggagggtccg atg 3326533DNAP. protegens 265gaattctaaa ctaacggaca ggagggtccg atg 3326633DNAP. protegens 266gaattctaag ctaacggaca ggagggtccg atg 3326733DNAP. protegens 267gaattcttaa ctaacggaca ggagggtccg atg 3326833DNAP. protegens 268gaattctaca ctaacggaca ggagggtcgg atg 3326933DNAP. protegens 269gaattctacg ctaacggaca ggagggtccg atg 3327033DNAP. protegens 270gaattctcaa ctaacggaca ggagggtccg atg 3327133DNAP. protegens 271gaattctaag ctaacggaca ggagggtcgg atg 3327233DNAP. protegens 272gaattctcag ctaacggaca ggagggtccg atg 3327333DNAP. protegens 273gaattctcaa ctaacggaca ggagggtccg atg 3327433DNAP. protegens 274gaattctacg ctaacggaca ggagggtcgg atg 3327535DNAP. protegens 275gaattctcaa ctaacggaca ggagatatac atatg 3527633DNAP. protegens 276gaattctcag ctaacggaca ggagggtcgg atg

3327733DNAP. protegens 277gaattctaaa ctaacggaca ggagggtcgg atg 3327833DNAP. protegens 278gaattctcag ctcacggaca ggagggtcgg atg 3327934DNAP. protegens 279gaattctcaa ctaacggaca ggagggtcgg gatg 3428033DNAP. protegens 280gaattctaca ctcacggaca ggagggtcgg atg 3328133DNAP. protegens 281gaattctaag ctcacggaca ggagggtcgg atg 3328233DNAP. protegens 282gaattctcaa ctcacggaca ggagggtcgg atg 3328333DNAP. protegens 283gaattctaca ctaacggaca gcagggtcgg atg 3328442DNAP. protegens 284ctagcgcagg tccaaccttt ttctaagcaa gtaggtcata tg 4228533DNAP. protegens 285gaattctcag ctaacggaca gcagggtcgg atg 3328642DNAP. protegens 286ctagcgcagg tccaaccttt ttctaagcaa ctaggtcata tg 4228742DNAP. protegens 287ctagcgaagg tccaaccttt ttctaagcca gtaggtcata tg 4228833DNAP. protegens 288gaattctacg ctcacggaca gcagggtcgg atg 3328933DNAP. protegens 289gaattctccg ctcacggaca ggagggtccg atg 3329033DNAP. protegens 290cttctcggcc agctgacagg ggaagctcgc atg 3329134DNAP. protegens 291cttctcggcc agctgacagg aggaagctcg catg 34292582PRTR. sphaeroides 292Met Asp Thr Ser Ala Ala Arg Ser Gly Ala Val Ala Glu Arg Gly Glu1 5 10 15Glu Tyr Leu Thr Leu Asp Ala Leu Cys Glu Ile Ala Lys Leu Leu Thr 20 25 30Gly Ala Ser Asp Pro Ile Ala Cys Met Pro Ala Val Phe Gly Val Leu 35 40 45Gly Ala Phe Met Gly Leu Arg His Gly Ala Leu Ala Ile Leu Gln Glu 50 55 60Gly Ala Gln Ala Glu Thr Gln Arg Asn Ala Arg His Val Asn Pro Tyr65 70 75 80Val Ile Ala Ala Thr Ala Ser Gly Val Pro Pro Ala Gly Ala Glu Ala 85 90 95Arg Ala Ile Pro Ala Gln Val Ala Arg His Val Phe Arg Asn Gly Val 100 105 110Ser Leu Val Ser Cys Asp Ile Leu Glu Glu Phe Gly Ala Glu Ala Leu 115 120 125Pro Pro Gly Leu Gly Asp Ser Arg Gln Ala Leu Val Ala Val Pro Ile 130 135 140Arg Asp Gln Ala Asn Ser Pro Phe Val Leu Gly Val Leu Cys Ala Tyr145 150 155 160Arg Ser Leu Lys Asp Asn Gly Ala Arg Tyr Leu Asp Thr Asp Leu Arg 165 170 175Val Leu Asn Met Val Ala Ala Val Leu Glu Gln Ser Ile Arg Phe Arg 180 185 190Arg Leu Val Ala Arg Asp Arg Asp Arg Ile Val Gln Glu Ala Arg Glu 195 200 205Ala Ile Arg Val Ala Ala Glu Ala Thr Ala Gly Pro Pro Val Glu Ala 210 215 220Pro Ala Glu Leu Ala Leu Glu Gly Val Ile Gly Ser Ser Pro Ala Ile225 230 235 240Gln Arg Val Ile Gly Gln Ile Arg Lys Val Ala Gly Thr His Thr Pro 245 250 255Val Leu Leu Arg Gly Glu Ser Gly Thr Gly Lys Glu Val Phe Ala Arg 260 265 270Ala Leu His Ala Leu Ser Glu Arg Arg Asp Lys Ala Phe Ile Lys Val 275 280 285Asn Cys Ala Ala Leu Ser Gln Ser Leu Leu Glu Ser Glu Leu Phe Gly 290 295 300His Glu Lys Gly Ser Phe Thr Gly Ala Val Gln Gln Lys Lys Gly Arg305 310 315 320Pro Glu Met Ala Glu Gly Gly Thr Leu Phe Leu Asp Glu Ile Gly Glu 325 330 335Ile Ser Leu Glu Phe Gln Ala Lys Leu Leu Arg Ile Leu Gln Glu Gly 340 345 350Glu Phe Glu Arg Val Gly Gly Thr Arg Thr Leu Arg Val Asp Val Arg 355 360 365Leu Val Thr Ala Thr Asn Lys Asp Leu Glu Arg Ala Val Ala Asn Gly 370 375 380Thr Phe Arg Ala Asp Leu Tyr Phe Arg Ile Cys Val Val Pro Ile Val385 390 395 400Leu Pro Pro Leu Arg Asp Arg Lys Glu Asp Ile Gly Leu Leu Ala Gln 405 410 415Gly Leu Leu Glu Arg Phe Asn Lys Arg Asn Gly Met Lys Lys Lys Leu 420 425 430His Pro Ser Ala Val Ala Ala Leu Ala Gln Cys Asn Phe Pro Gly Asn 435 440 445Val Arg Glu Leu Glu Asn Cys Ile Ala Arg Val Ala Ala Leu Ser Pro 450 455 460Glu Thr Val Ile His Ala Asp Asp Leu Ala Cys His His Asp His Cys465 470 475 480Leu Ser Ala Asp Leu Trp Arg Leu Gln Thr Gly Ser Ala Ser Pro Val 485 490 495Gly Gly Leu Ala Gln Gly Pro Leu Glu Leu Pro Val Leu Gly Ser Arg 500 505 510Pro Pro Ala Ala Ala Pro Ser Ala Pro Pro Pro Pro Pro Pro Thr Val 515 520 525Pro Ser Ala Pro Leu Asp Gly Glu Ala Ala Glu Arg Glu Ala Leu Ile 530 535 540Glu Ala Met Glu Arg Ala Gly Trp Val Gln Ala Lys Ala Ala Arg Leu545 550 555 560Arg Gly Met Thr Pro Arg Gln Ile Gly Tyr Ala Leu Lys Lys Tyr Asn 565 570 575Ile Arg Val Glu Lys Phe 580293615PRTA. caulinodans 293Met Pro Met Thr Asp Ala Phe Gln Val Arg Val Pro Arg Val Ser Ser1 5 10 15Ser Thr Ala Gly Asp Ile Ala Ala Ser Ser Ile Thr Thr Arg Gly Ala 20 25 30Leu Pro Arg Pro Gly Gly Met Pro Val Ser Met Ser Arg Gly Thr Ser 35 40 45Pro Glu Val Ala Leu Ile Gly Val Tyr Glu Ile Ser Lys Ile Leu Thr 50 55 60Ala Pro Arg Arg Leu Glu Val Thr Leu Ala Asn Val Val Asn Val Leu65 70 75 80Ser Ser Met Leu Gln Met Arg His Gly Met Ile Cys Ile Leu Asp Ser 85 90 95Glu Gly Asp Pro Asp Met Val Ala Thr Thr Gly Trp Thr Pro Glu Met 100 105 110Ala Gly Gln Ile Arg Ala His Val Pro Gln Lys Ala Ile Asp Gln Ile 115 120 125Val Ala Thr Gln Met Pro Leu Val Val Gln Asp Val Thr Ala Asp Pro 130 135 140Leu Phe Ala Gly His Glu Asp Leu Phe Gly Pro Pro Glu Glu Ala Thr145 150 155 160Val Ser Phe Ile Gly Val Pro Ile Lys Ala Asp His His Val Met Gly 165 170 175Thr Leu Ser Ile Asp Arg Ile Trp Asp Gly Thr Ala Arg Phe Arg Phe 180 185 190Asp Glu Asp Val Arg Phe Leu Thr Met Val Ala Asn Leu Val Gly Gln 195 200 205Thr Val Arg Leu His Lys Leu Val Ala Ser Asp Arg Asp Arg Leu Ile 210 215 220Ala Gln Thr His Arg Leu Glu Lys Ala Leu Arg Glu Glu Lys Ser Gly225 230 235 240Ala Glu Pro Glu Val Ala Glu Ala Ala Asn Gly Ser Ala Met Gly Ile 245 250 255Val Gly Asp Ser Pro Leu Val Lys Arg Leu Ile Ala Thr Ala Gln Val 260 265 270Val Ala Arg Ser Asn Ser Thr Val Leu Leu Arg Gly Glu Ser Gly Thr 275 280 285Gly Lys Glu Leu Phe Ala Arg Ala Ile His Glu Leu Ser Pro Arg Lys 290 295 300Gly Lys Pro Phe Val Lys Val Asn Cys Ala Ala Leu Pro Glu Ser Val305 310 315 320Leu Glu Ser Glu Leu Phe Gly His Glu Lys Gly Ala Phe Thr Gly Ala 325 330 335Leu Asn Met Arg Gln Gly Arg Phe Glu Leu Ala His Gly Gly Thr Leu 340 345 350Phe Leu Asp Glu Ile Asp Glu Ile Thr Pro Ala Phe Gln Ala Lys Leu 355 360 365Leu Arg Val Leu Gln Glu Gly Glu Phe Glu Arg Val Gly Gly Asn Arg 370 375 380Thr Leu Lys Val Asp Val Arg Leu Val Cys Ala Thr Asn Lys Asn Leu385 390 395 400Glu Glu Ala Val Ser Lys Gly Glu Phe Arg Ala Asp Leu Tyr Tyr Arg 405 410 415Ile His Val Val Pro Leu Ile Leu Pro Pro Leu Arg Glu Arg Pro Gly 420 425 430Asp Ile Pro Lys Leu Ala Lys Asn Phe Leu Asp Arg Phe Asn Lys Glu 435 440 445Asn Lys Leu His Met Met Leu Ser Ala Pro Ala Ile Asp Val Leu Arg 450 455 460Arg Cys Tyr Phe Pro Gly Asn Val Arg Glu Leu Glu Asn Cys Ile Arg465 470 475 480Arg Thr Ala Thr Leu Ala His Asp Ala Val Ile Thr Pro His Asp Phe 485 490 495Ala Cys Asp Ser Gly Gln Cys Leu Ser Ala Met Leu Trp Lys Gly Ser 500 505 510Ala Pro Lys Pro Val Met Pro His Val Pro Pro Ala Pro Thr Pro Leu 515 520 525Thr Pro Leu Ser Pro Ala Pro Leu Ala Thr Ala Ala Pro Ala Ala Ala 530 535 540Ser Pro Ala Pro Ala Ala Asp Ser Leu Pro Val Thr Cys Pro Gly Thr545 550 555 560Glu Ala Cys Pro Ala Val Pro Pro Arg Gln Ser Glu Lys Glu Gln Leu 565 570 575Leu Gln Ala Met Glu Arg Ser Gly Trp Val Gln Ala Lys Ala Ala Arg 580 585 590Leu Leu Asn Leu Thr Pro Arg Gln Val Gly Tyr Ala Leu Arg Lys Tyr 595 600 605Asp Ile Asp Ile Lys Arg Phe 610 615

Claims

1. A rhizobium that can fix nitrogen under aerobic free-living conditions, comprising a symbiotic rhizobium having an exogenous nif cluster, wherein the exogenous nif cluster confers nitrogen fixation capability on the symbiotic rhizobium under aerobic free-living conditions, and wherein the rhizobium is not Azorhizobium caulinodans.

2. The rhizobium of claim 1, wherein the exogenous nif cluster is selected from a group consisting of a free-living diazotroph, a symbiotic diazotroph, a photosynthetic Alphaproteobacteria, a Gammaproteobacteria, a cyanobacteria, a firmicutes, a Rhodobacter sphaeroides, and a Rhodopseudomonas palustris.

3. The rhizobium of claim 1, wherein the exogenous nif cluster is an inducible refactored nif cluster.

4. The rhizobium of claim 3, wherein the inducible refactored nif cluster is an inducible refactored Klebsiella nif cluster.

5. The rhizobium of claim 1, wherein the rhizobium is IRBG74.

6. The rhizobium of claim 1, wherein the exogenous nif cluster comprises 6 nif genes or operons.

7. The rhizobium of claim 6, wherein the 6 nif genes or operons are nifHDK(T)Y, nifEN(X), nifJ, nifBQ, nifF, and nifUSVWZM.

8. The rhizobium of claim 6, wherein each nif gene or operon of the exogenous nif cluster is preceded by a T7 promoter.

9. The rhizobium of claim 1, further comprising an endogenous nif cluster.

10. The rhizobium of claim 1, wherein the exogenous nif cluster further comprises a terminator.

11. The rhizobium of claim 8, wherein the T7 promoter has a terminator and wherein the terminator is downstream from the T7 promoter.

12. The rhizobium of claim 11, wherein the exogenous nif cluster is a refactored rhizobium IRBG74 nif cluster.

13-33. (canceled)

34. A method for making a nitrogen-fixing bacterium, the method comprising: a) identifying a host bacterium; b) selecting a donor bacterium having a nif cluster based on evolutionary distance between the host bacterium and the donor bacterium; c) inserting the nif cluster of the donor bacterium to the host bacterium, thereby making a nitrogen-fixing bacterium.

35. The method of claim 34, wherein the evolutionary distance between the host bacterium and the donor bacterium is less than 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, or 0.1% substitutions per site in 16S ribosomal RNA gene sequence.

36. The method of claim 34, wherein the host bacterium and the donor bacterium are in the same genus, family, order, or class.

37-39. (canceled)

40. The method of claim 34, wherein the host bacterium is E. coli and the donor bacterium is K. oxytoca.

41. (canceled)

42. The method of claim 34, wherein the host bacterium is Rhizobium IRBG74, and the donor bacterium is R. sphaeroides.

43. The method of claim 34, wherein the host bacterium is a nonsymbiotic bacterium, e.g., Azotobacter, Beijerinckia, or Clostridium bacterium.

44-45. (canceled)

46. The method of claim 34, wherein the inserted nif cluster is under inducible control.

47-59. (canceled)