Method for producing L-glutamic acid by fermentation accompanied by precipitation

Abstract

A microorganism is provided which can metabolize a carbon source at a specific pH in a liquid medium containing L-glutamic acid at a saturation concentration and the carbon source, and which has ability to accumulate L-glutamic acid in an amount exceeding the amount corresponding to the saturation concentration in the liquid medium at the pH. Also provided is a method for producing L-glutamic acid by fermentation, which comprises culturing the microorganism in a liquid medium of which pH is adjusted to a pH at which L-glutamic acid is precipitated, to produce and accumulate L-glutamic acid and precipitate L-glutamic acid in the medium.

Parent Case Text

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. Ser. No. 09/641,892, filed on Aug. 18, 2000 (now U.S. Pat. No. 7,015,010), which claims priority to Japanese application No. JP 11-234806, filed on Aug. 20, 1999, and to Japanese application No. JP 2000-78771, filed on Mar. 21, 2000.

Description

BACKGROUND OF THE INVENTION

The present invention relates to a method for producing L-glutamic acid by fermentation accompanied by precipitation. L-Glutamic acid is widely used as a material for seasonings and so forth.

L-Glutamic acid is mainly produced by fermentative methods using so-called coryneformbacteria producing L-glutamic acid, which belong to the genus Brevibacterium, Corynebacterium or Microbacterium, or mutant strains thereof (Amino Acid Fermentation, pp. 195-215, Gakkai Shuppan Center, 1986). Methods for producing L-glutamic acid by fermentation using other bacterial strains are known and include a method using a microorganism belonging to the genus Bacillus, Streptomyces, Penicillium or the like (U.S. Pat. No. 3,220,929), a method using a microorganism belonging to the genus Pseudomonas, Arthrobacter, Serratia, Candida or the like (U.S. Pat. No. 3,563,857), a method using a microorganism belonging to the genus Bacillus, Pseudomonas, Serratia, Aerobacter aerogenes (currently referred to as Enterobacter aerogenes) or the like (Japanese Patent Publication (Kokoku) No. 32-9393), a method using a mutant strain of Escherichia coli (Japanese Patent Application Laid-open (Kokai) No. 5-244970) and so forth. In addition, the inventors of the present invention have proposed a method for producing L-glutamic acid by using a microorganism belonging to the genus Klebsiella, Erwinia or Pantoea (Japanese Patent Application Laid-open No. 2000-106869).

Further, there have been disclosed various techniques for improving L-glutamic acid-producing ability by enhancing activities of L-glutamic acid biosynthetic enzymes through the use of recombinant DNA techniques. For example, it has been reported that the introduction of a gene coding for citrate synthase derived from Escherichia coli or Corynebacterium glutamicum was effective for the enhancement of L-glutamic acid-producing ability in Corynebacterium or Brevibacterium bacteria (Japanese Patent Publication No. 7-121228). In addition, Japanese Patent Application Laid-open No. 61-268185 discloses a cell harboring recombinant DNA containing a glutamate dehydrogenase gene derived from Corynebacterium bacteria. Further, Japanese Patent Application Laid-open No. 63-214189 discloses a technique for improving L-glutamic acid-producing ability by amplifying a glutamate dehydrogenase gene, an isocitrate dehydrogenase gene, an aconitate hydratase gene and a citrate synthase gene.

Although L-glutamic acid productivity has been considerably increased by breeding of the aforementioned microorganisms or improvement of production methods, development of methods for more efficiently producing L-glutamic acid at a lower cost are still required to respond to the increasing future demand for L-glutamic acid.

A method wherein fermentation is performed with crystallizing L-amino acid accumulated in culture is known (Japanese Patent Application Laid-open No. 62-288). In this method, the L-amino acid concentration in the culture is maintained below a certain level by precipitating the accumulated L-amino acid in the culture. Specifically, L-tryptophan, L-tyrosine or L-leucine is precipitated during fermentation by adjusting the temperature and the pH of the culture or by adding a surface active agent to the medium.

While a fermentative method with precipitating L-amino acid is known as described above, amino acids suitable for this method are those of relatively low water solubility. No example exists for applying the method to highly water-soluble amino acids such as L-glutamic acid. In addition, the medium must have low pH to precipitate L-glutamic acid. However, L-glutamic acid-producing bacteria such as those mentioned above cannot grow under acidic conditions, and therefore L-glutamic acid fermentation is performed under neutral conditions (U.S. Pat. Nos. 3,220,929 and 3,032,474; Chao K. C. & Foster J. W., J. Bacteriol., 77, pp. 715-725 (1959)). Thus, production of L-glutamic acid by fermentation accompanied by precipitation is not known.

Furthermore, it is known that growth of most acidophile bacteria is inhibited by organic acids such as acetic acid, lactic acid and succinic acid (Yasuro Oshima Ed., "Extreme Environment Microorganism Handbook", p. 231, Science Forum; Borichewski R. M., J. Bacteriol., 93, pp. 597-599 (1967) etc.). Therefore, it is considered that many microorganisms are susceptible to L-glutamic acid, which is also an organic acid, under acidic conditions. There exists no report of microorganisms having L-glutamic acid-producing ability under acidic conditions has been attempted.

SUMMARY OF THE INVENTION

Based on the foregoing, an object of the present invention is to search and breed a microorganism that produces L-glutamic acid under low pH conditions and to provide a method for producing L-glutamic acid using an obtained microorganism by fermentation with precipitating L-glutamic acid.

The inventors of the present invention considered during the study for improvement of L-glutamic acid productivity by fermentation that inhibition of the production by L-glutamic acid accumulated in a medium at a high concentration was one of obstructions to the improvement of productivity. For example, cells have an excretory system and an uptake system for L-glutamic acid. However, if L-glutamic acid once excreted into the medium is incorporated into cells again, not only the production efficiency falls, but also the L-glutamic acid biosynthetic reactions are inhibited as a result. In order to avoid the inhibition of production by such accumulation of L-glutamic acid at high concentration, the inventors of the present invention screened microorganisms that can proliferate under acidic conditions and in the presence of a high concentration of L-glutamic acid. As a result, they successfully isolated microorganisms having such properties from a soil, and thus accomplished the present invention.

Thus, the present invention provides the following:

(1) A microorganism which can metabolize a carbon source at a specific pH in a liquid medium containing L-glutamic acid at a saturation concentration and the carbon source, and has ability to accumulate L-glutamic acid in an amount exceeding the amount corresponding to the saturation concentration in the liquid medium at the pH. (2) The microorganism according to (1), which can grow in the liquid medium. (3) The microorganism according to (1) or (2), wherein the pH is not more than 5.0. (4) The microorganism according to any one of (1) to (3), which has at least one of the following characteristics: (a) the microorganism is enhanced in activity of an enzyme that catalyzes a reaction for biosynthesis of L-glutamic acid; and (b) the microorganism is decreased in or deficient in activity of an enzyme that catalyzes a reaction branching from a biosynthetic pathway of L-glutamic acid and producing a compound other than L-glutamic acid. (5) The microorganism according to (4), wherein the enzyme that catalyzes the reaction for biosynthesis of L-glutamic acid is at least one selected from citrate synthase, phosphoenolpyruvate carboxylase and glutamate dehydrogenase. (6) The microorganism according to (4) or (5), wherein the enzyme that catalyzes the reaction branching from the biosynthetic pathway of L-glutamic acid and producing a compound other than L-glutamic acid is .alpha.-ketoglutarate dehydrogenase. (7) The microorganism according to any one of (1) to (6), wherein the microorganism belongs to the genus .[.Enterobacter.]. .Iadd.Pantoea.Iaddend.. (8) The microorganism according to (7), which is .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis.Iaddend.. (9) The microorganism according to (8), which has a mutation that causes less extracellular secretion of a viscous material compared with a wild strain when cultured in a medium containing a saccharide. (10) A method for producing L-glutamic acid by fermentation, which comprises culturing a microorganism as defined in any one of (1) to (9) in a liquid medium of which pH is adjusted to a pH at which L-glutamic acid is precipitated, to produce and accumulate L-glutamic acid and precipitate L-glutamic acid in the medium. (11) A method for screening a microorganism suitable for producing L-glutamic acid by fermentation with precipitating L-glutamic acid in a liquid medium, which comprises inoculating a sample containing microorganisms into an acidic medium containing L-glutamic acid at a saturation concentration and a carbon source, and selecting a strain that can metabolize the carbon source. (12) The method according to (11), wherein a strain that can grow in the medium is selected as the strain that can metabolize the carbon source. (13) The method according to (11) or (12), wherein a pH of the medium is not more than 5.0.

According to the method of the present invention, L-glutamic acid can be produced by fermentation with precipitating L-glutamic acid. As a result, L-glutamic acid in the medium is maintained below a certain concentration, and L-glutamic acid can be produced without suffering from the product inhibition by L-glutamic acid at a high concentration.

BRIEF EXPLANATION OF THE DRAWINGS

FIG. 1 shows a restriction map of a DNA fragment derived from .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.pTWVEK101.

FIG. 2A and FIG. 2B show a comparison of the amino acid sequence deduced from the nucleotide sequence of the sucA gene derived from .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.and that derived from Escherichia coli. Upper sequence: .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.(SEQ ID NO: 3), lower sequence: Escherichia coli (SEQ ID NO: 8) (the same shall apply hereafter).

FIG. 3 shows comparison of the amino acid sequence deduced from the nucleotide sequence of the sucB gene derived from .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.(upper sequence--SEQ ID NO: 4) and that derived from Escherichia coli (lower sequence--SEQ ID NO: 9).

FIG. 4 shows comparison of the amino acid sequence deduced from the nucleotide sequence of the sucC gene derived from .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.(upper sequence--SEQ ID NO: 10) and that derived from Escherichia coli (lower sequence--SEQ ID NO: 11).

FIG. 5 shows comparison of the amino acid sequence deduced from the nucleotide sequence of the sdhB gene derived from .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.(upper sequence--SEQ ID NO: 2) and that derived from Escherichia coli (lower sequence--SEQ ID NO: 12).

FIG. 6 shows construction of plasmid pMWCPG having a gltA gene, a ppc gene and a gdhA gene.

FIG. 7 shows construction of plasmid RSF-Tet having the replication origin of the broad host spectrum plasmid RSF1010 and a tetracycline resistance gene.

FIG. 8 shows construction of plasmid RSFCPG having the replication origin of the broad host spectrum plasmid RSF1010 a tetracycline resistance gene, a gltA gene, a ppc gene and a gdhA gene.

FIG. 9 shows construction of plasmid pSTVCB having a gltA gene.

DETAILED DESCRIPTION OF THE INVENTION

Hereafter, the present invention will be explained in detail.

The microorganism of the present invention is a microorganism that (1) can metabolize a carbon source at a specific pH in a liquid medium containing L-glutamic acid at a saturation concentration and the carbon source and (2) has ability to accumulate L-glutamic acid in an amount exceeding the amount corresponding to the saturation concentration in the liquid medium at the pH.

The term "saturation concentration" means a concentration of L-glutamic acid dissolved in a liquid medium when the liquid medium is saturated with L-glutamic acid.

Hereafter, a method for screening a microorganism that can metabolize a carbon source in a liquid medium containing L-glutamic acid at a saturation concentration and the carbon source at a specific pH will be described. A sample containing microorganisms is inoculated into a liquid medium containing L-glutamic acid at a saturation concentration and a carbon source at a specific pH, and a strain that can metabolize the carbon source is selected. The specific pH is not particularly limited, but is usually not more than about 5.0, preferably not more than about 4.5, more preferably not more than about 4.3. The microorganism of the present invention is used to produce L-glutamic acid by fermentation with precipitating L-glutamic acid. If the pH is too high, it becomes difficult to allow the microorganism to produce L-glutamic acid enough for precipitation. Therefore, pH is preferably in the aforementioned range.

If pH of an aqueous solution containing L-glutamic acid is lowered, the solubility of L-glutamic acid significantly falls around pKa of .gamma.-carboxyl group (4.25, 25.degree. C.). The solubility becomes the lowest at the isoelectric point (pH 3.2) and L-glutamic acid exceeding the amount corresponding to the saturation concentration is precipitated. While it depends on the medium composition, L-glutamic acid is usually dissolved in an amount of 10 to 20 g/L at pH 3.2, 30 to 40 g/L at pH 4.0 and 50 to 60 g/L at pH 4.7, at about 30.degree. C. Usually pH does not need to be made below 3.0, because the L-glutamic acid precipitating effect plateaus when pH goes below a certain value. However, pH may be below 3.0.

In addition, the expression that a microorganism "can metabolize the carbon source" means that it can proliferate or can consume the carbon source even though it cannot proliferate. Therefore, this phrase indicates that the microorganism catabolizes carbon sources such as saccharides or organic acids. Specifically, for example, if a microorganism proliferates when cultured in a liquid medium containing L-glutamic acid at a saturation concentration at pH 5.0 to 4.0, preferably pH 4.5 to 4.0, more preferably pH 4.3 to 4.0, still more preferably pH 4.0 at an appropriate temperature, for example, 28.degree. C., 37.degree. C. or 50.degree. C. for 2 to 4 days, this microorganism can metabolize the carbon source in the medium.

Further, for example, even if a microorganism does not proliferate when it is cultured in a liquid medium containing L-glutamic acid at a saturation concentration at pH 5.0 to 4.0, preferably pH 4.5 to 4.0, more preferably pH 4.3 to 4.0, still more preferably pH 4.0 at an appropriate temperature, for example, 28.degree. C., 37.degree. C. or 50.degree. C. for 2 to 4 days, the microorganism which consumes the carbon source in the medium is that can metabolize the carbon source in the medium.

The microorganism which can metabolize the carbon source includes a microorganism which can grow in the liquid medium.

The expression that a microorganism "can grow" means that it can proliferate or can produce L-glutamic acid even though it cannot proliferate. Specifically, for example, if a microorganism proliferates when cultured in a liquid medium containing L-glutamic acid at a saturation concentration at pH 5.0 to 4.0, preferably pH 4.5 to 4.0, more preferably pH 4.3 to 4.0, still more preferably pH 4.0 at an appropriate temperature, for example, 28.degree. C., 37.degree. C. or 50.degree. C. for 2 to 4 days, this microorganism can grow in the medium.

Further, for example, even if a microorganism does not proliferate when it is cultured in a liquid synthetic medium containing L-glutamic acid at a saturation concentration at pH 5.0 to 4.0, preferably pH 4.5 to 4.0, more preferably pH 4.3 to 4.0, still more preferably pH 4.0 at an appropriate temperature, for example, 28.degree. C., 37.degree. C. or 50.degree. C. for 2 to 4 days, the microorganism which increases the amount of L-glutamic acid in the medium is that can grow in the medium.

The selection described above may be repeated two or more times under the same conditions or with changing pH or the concentration of L-glutamic acid. An initial selection can be performed in a medium containing L-glutamic acid at a concentration lower than the saturation concentration, and thereafter a subsequent selection can be performed in a medium containing L-glutamic acid at a saturation concentration. Further, strains with favorable properties such as superior proliferation rate may be selected.

In addition to the property described above, the microorganism of the present invention has an ability to accumulate L-glutamic acid in an amount exceeding the amount corresponding to the saturation concentration of L-glutamic acid in a liquid medium. The pH of the aforementioned liquid medium is preferably the same as or close to that of the medium used for screening a microorganism having the aforementioned property (1). Usually, a microorganism becomes susceptible to L-glutamic acid at a high concentration as pH becomes lower. Therefore, it is preferred that pH is not low from the viewpoint of resistance to L-glutamic acid, but low pH is preferred from the viewpoint of production of L-glutamic acid with precipitating it. To satisfy these conditions, pH may be in the range of 3 to 5, preferably 4 to 5, more preferably 4.0 to 4.7, still more preferably 4.0 to 4.5, particularly preferably 4.0 to 4.3.

As the microorganism of the present invention or breeding materials therefor, there can be mentioned, for example, microorganisms belonging to the genus Enterobacter, Klebsiella, Serratia, Pantoea, Erwinia, Escherichia, Corynebacterium, Alicyclobacillus, Bacillus, Saccharomyces or the like. Among these, microorganisms belonging to the genus Enterobacter are preferred. Hereafter, the microorganism of the present invention will be explained mainly for microorganisms belonging to the genus Enterobacter, but the present invention can be applied to microorganism belonging to other genera and not limited to the genus Enterobacter.

As microorganisms belonging to the .[.Enterobacter.]. .Iadd.Pantoea.Iaddend., there can be specifically mentioned .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis.Iaddend., preferably the .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13355 strain. This strain was isolated from a soil in Iwata-shi, Shizuoka, Japan as a strain that can proliferate in a medium containing L-glutamic acid and a carbon source at low pH.

The physiological properties of AJ13355 are as follows:

(1) Gram staining: negative

(2) Behavior against oxygen: facultative anaerobic

(3) Catalase: positive

(4) Oxidase: negative

(5) Nitrate-reducing ability: negative

(6) Voges-Proskauer test: positive

(7) Methyl Red test: negative

(8) Urease: negative

(9) Indole production: positive

(10) Motility: motile

(11) H.sub.2S production in TSI medium: weakly active

(12) .beta.-galactosidase: positive

(13) Saccharide-assimilating property:

Arabinose: positive

Sucrose: positive

Lactose: positive

Xylose: positive

Sorbitol: positive

Inositol: positive

Trehalose: positive

Maltose: positive

Glucose: positive

Adonitol: negative

Raffinose: positive

Salicin: negative

Melibiose: positive

(14) Glycerol-assimilating property: positive

(15) Organic acid-assimilating property:

Citric acid: positive

Tartaric acid: negative

Gluconic acid: positive

Acetic acid: positive

Malonic acid: negative

(16) Arginine dehydratase: negative

(17) Ornithine decarboxylase: negative

(18) Lysine decarboxylase: negative

(19) Phenylalanine deaminase: negative

(20) Pigment formation: yellow

(21) Gelatin liquefaction ability: positive

(22) Growth pH: growth is possible at pH 4.0, good growth at pH 4.5 to 7

(23) Growth temperature: good growth at 25.degree. C., good growth at 30.degree. C., good growth at 37.degree. C., growth is possible at 42.degree. C., growth is not possible at 45.degree. C.

Based on these bacteriological properties, AJ13355 was determined as .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis.Iaddend..

The .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13355 was deposited at the National Institute of Bioscience and Human-Technology, Agency of Industrial Science and Technology, Ministry of International Trade and Industry (postal code: 305-8566, 1-3, Higashi 1-chome, Tsukuba-shi, Ibaraki, Japan) on Feb. 19, 1998 and received an accession number of FERM P-16644. It was then transferred to an international deposition under the provisions of Budapest Treaty on Jan. 11, 1999 and received an accession number of FERM BP-6614.

The microorganism of the present invention may be a microorganism originally having L-glutamic acid-producing ability or one having L-glutamic acid-producing ability imparted or enhanced by breeding through use of mutation treatment, recombinant DNA techniques or the like.

L-Glutamic acid-producing ability can be imparted or enhanced by, for example, increasing activity of an enzyme that catalyzes a reaction for biosynthesis of L-glutamic acid. L-Glutamic acid-producing ability can also be enhanced by decreasing activity of an enzyme that catalyzes a reaction branching from the biosynthetic pathway of L-glutamic acid and producing a compound other than L-glutamic acid, or making the activity deficient.

Enzymes that catalyze are action for biosynthesis of L-glutamic acid, include: glutamate dehydrogenase (hereafter, also referred to as "GDH"), glutamine synthetase, glutamate synthase, isocitrate dehydrogenase, aconitate hydratase, citrate synthase (hereafter, also referred to as "CS"), phosphoenolpyruvate carboxylase (hereafter, also referred to as "PEPC"), pyruvate dehydrogenase, pyruvate kinase, enolase, phosphoglyceromutase, phosphoglycerate kinase, glyceraldehyde-3-phosphate dehydrogenase, triosephosphate isomerase, fructose bisphosphate aldolase, phosphofructokinase, glucose phosphate isomerase and so forth. Among these enzymes, one, two or three of CS, PEPC and GDH are preferred. Further, it is preferred that the activities of all the three enzymes, CS, PEPC and GDH, are enhanced in the microorganism of the present invention. In particular, CS of Brevibacterium lactofermentum is preferred, because it does not suffer from inhibition by .alpha.-ketoglutaric acid, L-glutamic acid and NADH.

In order to enhance the activity of CS, PEPC or GDH, for example, a gene coding for CS, PEPC or GDH may be cloned on an appropriate plasmid and a host microorganism may be transformed with the obtained plasmid. The copy number of the gene coding for CS, PEPC or GDH (hereafter, abbreviated as "gltA gene", "ppc gene" and "gdhA gene", respectively) in the transformed strain cell increases, resulting in the increase of the activity of CS, PEPC or GDH.

The cloned gltA gene, ppc gene and gdhA gene are introduced into the aforementioned starting parent strain solely or in combination of arbitrary two or three kinds of them. When two or three kinds of the genes are introduced, two or three kinds of the genes may be cloned on one kind of plasmid and introduced into the host, or separately cloned on two or three kinds of plasmids that can coexist and introduced into the host.

Two or more kinds of genes coding for enzymes of the same kind, but derived from different microorganisms may be introduced into the same host.

The plasmids described above are not particularly limited so long as they are autonomously replicable in cells of a microorganism belonging to, for example, the genus Enterobacter or the like, but, for example, there can be mentioned pUC19, pUC18, pBR322, pHSG299, pHSG298, pHSG399, pHSG398, RSF1010, pMW119, pMW118, pMW219, pMW218, pACYC177, pACYC184 and so forth. Besides these, vectors of phage DNA can also be used.

Transformation can be performed by, for example, the method of D. M. Morrison (Methods in Enzymology, 68, 326 (1979)), the method wherein permeability of DNA is increased by treating recipient bacterium cells with calcium chloride (Mandel M. and Higa A., J. Mol. Biol., 53, 159 (1970)), the electroporation (Miller J. H., "A Short Course in Bacterial Genetics", Cold Spring Harbor Laboratory Press, U.S.A. 1992) or the like.

The activity of CS, PEPC or GDH can also be increased by allowing multiple copies of a gltA gene, a ppc gene or a gdhA gene to be present on chromosomal DNA of the aforementioned starting parent strain to be a host. In order to introduce multiple copies of the gltA gene, the ppc gene or the gdhA gene on chromosomal DNA of a microorganism belonging to the genus Enterobacter or the like, a sequence of which multiple copies are present on the chromosomal DNA, such as repetitive DNA and inverted repeats present at termini of a transposable element, can be used. Alternatively, multiple copies of the genes can be introduced on to chromosomal DNA by utilizing transfer of a transposon containing the gltA gene, the ppc gene or the gdhA gene. As a result, the copy number of the gltA gene, the ppc gene or the gdhA gene in a transformed strain cell is increased, and thus the activity of CS, PEPC or GDH is increased.

As organisms to be a source of the gltA gene, the ppc gene or the gdhA gene of which copy number is increased, any organism can be used so long as it has activity of CS, PEPC or GDH. Inter alia, bacteria, which are prokaryotes, for example, those belonging to the genus Enterobacter, Klebsiella, Erwinia, Pantoea, Serratia, Escherichia, Corynebacterium, Brevibacterium and Bacillus are preferred. As specific examples, there can be mentioned Escherichia coli, Brevibacterium lactofermentum and so forth. The gltA gene, the ppc gene and the gdhA gene can be obtained from chromosomal DNA of the microorganisms described above.

The gltA gene, the ppc gene and the gdhA gene can be obtained by using a mutant strain which is deficient in the activity of CS, PEPC or GDH to isolate a DNA fragment which complements the auxotrophy from chromosomal DNA of the aforementioned microorganisms. Since the nucleotide sequences of these genes of Escherichia and Corynebacterium bacteria have already been elucidated (Biochemistry, 22, pp. 5243-5249 (1983); J. Biochem., 95, pp. 909-916 (1984); Gene, 27, pp. 193-199 (1984); Microbiology, 140, pp. 1817-1828 (1994); Mol. Gen. Genet., 218, pp. 330-339 (1989); Molecular Microbiology, 6, pp. 317-326 (1992)), they can also be obtained by PCR utilizing primers synthesized based on each nucleotide sequence and chromosomal DNA as a template.

The activity of CS, PEPC or GDH can also be increased by enhancing the expression of the gltA gene, the ppc gene or the gdhA gene besides the aforementioned amplification of the genes. For example, the expression can be enhanced by replacing a promoter for the gltA gene, the ppc gene or the gdhA gene with other stronger promoters. For example, strong promoters are known to include: lac promoter, trp promoter, trc promoter, tac promoter, P.sub.R promoter and P.sub.L promoter of the lamda phage and so forth. The gltA gene, the ppc gene and the gdhA gene of which promoter is replaced are cloned on a plasmid and introduced into the host microorganism, or introduced onto the chromosomal DNA of the host microorganism by using repetitive DNA, inverted repeats, transposon or the like.

The activity of CS, PEPC or GDH can also be enhanced by replacing the promoter of the gltA gene, the ppc gene or the gdhA gene on the chromosome with other stronger promoters (see WO 87/03006 and Japanese Patent Application Laid-open No. 61-268183), or inserting a strong promoter in the upstream of the coding sequence of each gene (see Gene, 29, pp. 231-241 (1984)). Specifically, homologous recombination can be performed between DNA containing the gltA gene, the ppc gene or the gdhA gene of which promoter is replaced with a stronger one or a part thereof and the corresponding gene on the chromosome.

Examples of the enzyme which catalyze a reaction branching from the biosynthetic pathway of the L-glutamic acid and producing a compound other than L-glutamic acid include .alpha.-ketoglutarate dehydrogenase (hereafter, also referred to as ".alpha.KGDH"), isocitrate lyase, phosphate acetyltransferase, acetate kinase, acetohydroxy acid synthase, acetolactate synthase, formate acetyltransferase, lactate dehydrogenase, glutamate decarboxylase, 1-pyrroline dehydrogenase and so forth. Among these enzymes, .alpha.KGDH is preferred.

In order to obtain a decrease or deficiency of the activity of the aforementioned enzyme in a microorganism belonging to the genus Enterobacter or the like, mutation causing decrease or deficiency of the intracellular activity of the enzyme can be introduced into the gene of the aforementioned enzyme by a usual mutagenesis or genetic engineering method.

Examples of the mutagenesis method include, for example, methods utilizing irradiation with X-ray or ultraviolet ray, methods utilizing treatment with a mutagenic agent such as N-methyl-N'-nitro-N-nitrosoguanidine, and so forth. The site where the mutation is introduced to the gene may be in a coding region coding for an enzyme protein, or a region for regulating expression such as a promoter.

Examples of the genetic engineering methods include, for example, methods utilizing gene recombination, transduction, cell fusion and so forth. For example, a drug resistance gene is inserted into a cloned target gene to prepare a gene that has lost its function (defective gene). Subsequently, this defective gene is introduced into a cell of a host microorganism, and the target gene on the chromosome is replaced with the aforementioned defective gene by utilizing homologous recombination (gene disruption).

A decrease or deficiency of intracellular activity of the target enzyme and the degree of decrease of the activity can be determined by measuring the enzyme activity of a cell extract or a purified fraction thereof obtained from a candidate strain and comparing with that of a wild strain. For example, the .alpha.KGDH activity can be measured by the method of Reed et al. (Reed L. J. and Mukherjee B. B., Methods in Enzymology, 13, pp. 55-61 (1969)).

Depending on the target enzyme, the target mutant strain can be selected based on the phenotype of the mutant strain. For example, a mutant strain which is deficient in the .alpha.KGDH activity or decreases in the .alpha.KGDH activity cannot proliferate or shows a markedly reduced proliferation rate in a minimal medium containing glucose or a minimal medium containing acetic acid or L-glutamic acid as an exclusive carbon source under aerobic conditions. However, normal proliferation is enabled even under the same condition by adding succinic acid or lysine, methionine and diaminopimelic acid to a minimal medium containing glucose. By utilizing these phenomena as indicators, mutant strains with decreased .alpha.KGDH activity or deficient in the activity can be selected.

A method for preparing the .alpha.KGDH gene deficient strain of Brevibacterium lactofermentum by utilizing homologous recombination is described in detail in WO 95/34672. Similar methods can be applied to the other microorganisms.

Further, techniques such as cloning of genes and cleavage and ligation of DNA, transformation and so forth are described in detail in Molecular Cloning, 2nd Edition, Cold Spring Harbor Press, 1989 and so forth.

As a specific example of a mutant strain deficient in .alpha.KGDH activity or with decreased .alpha.KGDH activity obtained as described above, there can be mentioned .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13356. .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13356 was deposited at the National Institute of Bioscience and Human-Technology, Agency of Industrial Science and Technology, Ministry of International Trade and Industry (postal code: 305-8566, 1-3, Higashi 1-chome, Tsukuba-shi, Ibaraki, Japan) on Feb. 19, 1998 and received an accession number of FERM P-16645. It was then transferred to an international deposition under the provisions of Budapest Treaty on Jan. 11, 1999 and received an accession number of FERM BP-6615. The .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13356 is deficient in .alpha.KGDH activity as a result of disruption of the .alpha.KGDH-E1 subunit gene (sucA).

When .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis.Iaddend., an example of the microorganism used in the present invention, is cultured in a medium containing a saccharide, a viscous material is extracellularly secreted, resulting in low operation efficiency. Therefore, when .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.having such a property of secreting the viscous material is used, it is preferable to use a mutant strain that secretes less the viscous material compared with a wild strain. Examples of mutagenesis methods include, for example, methods utilizing irradiation with X ray or ultraviolet ray, method utilizing treatment with a mutagenic agent such as N-methyl-N'-nitro-N-nitrosoguanidine and so forth. A mutant strain with decreased secretion of the viscous material can be selected by inoculating mutagenized bacterial cells in a medium containing a saccharide, for example, LB medium plate containing 5 g/L of glucose, culturing them with tilting the plate about 45 degrees and selecting a colony which does not show flowing down of liquid.

In the present invention, impartation or enhancement of L-glutamic acid-producing ability and impartation of other favorable properties such as mutation for less viscous material secretion described above can be carried out in an arbitrary order.

By culturing the microorganism of the present invention in a liquid medium of which pH is adjusted to a pH at which L-glutamic acid is precipitated, L-glutamic acid can be produced and accumulated with precipitating it in the medium. L-Glutamic acid can also be precipitated by starting the culture at a neutral pH and then ending it at a pH at which L-glutamic acid is precipitated.

The pH at which L-glutamic acid is precipitated means one at which L-glutamic acid is precipitated when the microorganism produces and accumulates L-glutamic acid.

As the aforementioned medium, a usual nutrient medium containing a carbon source, a nitrogen source, mineral salts and organic trace nutrients such as amino acids and vitamins as required can be used so long as pH is adjusted to a pH at which L-glutamic acid is precipitated. Either a synthetic medium or a natural medium can be used. The carbon source and the nitrogen source used in the medium can be any ones so long as they can be used by the cultured strain.

As the carbon source, saccharides such as glucose, glycerol, fructose, sucrose, maltose, mannose, galactose, starch hydrolysate and molasses are used. In addition, organic acids such as acetic acid and citric acid may be used each alone or in combination with another carbon source.

As the nitrogen source, ammonia, ammonium salts such as ammonium sulfate, ammonium carbonate, ammonium chloride, ammonium phosphate and ammonium acetate, nitrates and so forth are used.

As the organic trace nutrients, amino acids, vitamins, fatty acids, nucleic acids, those containing these substances such as peptone, casamino acid, yeast extract and soybean protein decomposition products are used. When an auxotrophic mutant strain that requires an amino acid and so forth for metabolization or growth is used, the required nutrient must be supplemented.

As mineral salts, phosphates, magnesium salts, calcium salts, iron salts, manganese salts and so forth are used.

As for the culture method, aeration culture is usually performed with controlling the fermentation temperature to be 20 to 42.degree. C. and pH to be 3 to 5, preferably 4 to 5, more preferably 4 to 4.7, particularly preferably 4 to 4.5. Thus, after about 10 hours to 4 days of culture, a substantial amount of L-glutamic acid is accumulated in the culture. Accumulated L-glutamic acid exceeding the amount corresponding to the saturation concentration is precipitated in the medium.

After completion of the culture, L-glutamic acid precipitated in the culture can be collected by centrifugation, filtration or the like. L-Glutamic acid dissolved in the medium can be collected according to known methods. For example, the L-glutamic acid can be isolated by concentrating the culture broth to crystallize it or isolated by ion exchange chromatography or the like. L-Glutamic acid precipitated in the culture broth may be isolated together with L-glutamic acid that have been dissolved in the medium after it is crystallized.

According to the method of the present invention, L-glutamic acid exceeding the amount corresponding to the saturation concentration is precipitated, and the concentration of L-glutamic acid dissolved in the medium is maintained at a constant level. Therefore, influence of L-glutamic acid at a high concentration on microorganisms can be reduced. Accordingly, it becomes possible to breed a microorganism having further improved L-glutamic acid-producing ability. Further, since L-glutamic acid is precipitated as crystals, acidification of the culture broth by accumulation of L-glutamic acid is suppressed, and therefore the amount of alkali used for maintaining pH of the culture can significantly be reduced.

EXAMPLES

Hereafter, the present invention will be more specifically explained with reference to the following examples.

<1> Screening of Microorganism Having L-Glutamic Acid Resistance in Acidic Environment

Screening of a microorganism having L-glutamic acid resistance in an acidic environment was performed as follows. Each of about 500 samples obtained from nature including soil, fruits, plant bodies, river water in an amount of 1 g was suspended in 5 mL of sterilized water, of which 200 .mu.L, was coated on 20 mL of solid medium of which pH was adjusted to 4.0 with HCl. The composition of the medium was as follows: 3 g/L of glucose, 1 g/L of (NH.sub.4).sub.2SO.sub.4, 0.2 g/L of MgSO.sub.4.7H.sub.2O, 0.5 g/L of KH.sub.2PO.sub.4, 0.2 g/L of NaCl, 0.1 g/L of CaCl.sub.2.7H.sub.2O, 0.01 g/L of FeSO.sub.4.7H.sub.2O, 0.01 g/L of MnSO.sub.4.4H.sub.2O, 0.72 mg/L of ZnSO.sub.4.2H.sub.2O, 0.64 mg/L of CuSO.sub.4.5H.sub.2O, 0.72 mg/L of CoCl.sub.2.6H.sub.2O, 0.4 mg/L of boric acid, 1.2 mg/L of Na.sub.2MoO.sub.4.2H.sub.2O, 50 .mu.g/L of biotin, 50 .mu.g/L of calcium pantothenate, 50 .mu.g/L of folic acid, 50 .mu.g/L of inositol, 50 .mu.g/L of niacin, 50 .mu.g/L of p-aminobenzoic acid, 50 .mu.g/L of pyridoxine hydrochloride, 50 .mu.g/L of riboflavin, 50 .mu.g/L of thiamine hydrochloride, 50 mg/L of cycloheximide, 20 g/L of agar.

The media plated on which the above samples were plated were incubated at 28.degree. C., 37.degree. C. or 50.degree. C. for 2 to 4 days and 378 strains each forming a colony were obtained.

Subsequently, each of the strains obtained as described above was inoculated in a test tube of 16.5 cm in length and 14 mm in a diameter containing 3 mL of liquid medium (adjusted to pH 4.0 with HCl) containing a saturation concentration of L-glutamic acid and cultured at 28.degree. C., 37.degree. C. or 50.degree. C. for 24 hours to 3 days with shaking. Then, the grown strains were selected. The composition of the aforementioned medium was follows: 40 g/L of glucose, 20 g/L of (NH.sub.4).sub.2SO.sub.4, 0.5 g/L of MgSO.sub.4.7H.sub.2O, 2 g/L of KH.sub.2PO.sub.4, 0.5 g/L of NaCl, 0.25 g/L of CaCl.sub.2.7H.sub.2O, 0.02 g/L of FeSO.sub.4.7H.sub.2O, 0.02 g/L of MnSO.sub.4.4H.sub.2O, 0.72 mg/L of ZnSO.sub.4.2H.sub.2O, 0.64 mg/L of CuSO.sub.4.5H.sub.2O, 0.72 mg/L of CoCl.sub.2.6H.sub.2O, 0.4 mg/L of boric acid, 1.2 mg/L of Na.sub.2MoO.sub.2.2H.sub.2O, 2 g/L of yeast extract.

Thus, 78 strains of microorganisms having L-glutamic acid resistance in an acidic environment were successfully obtained.

<2> Selection of Strains with Superior Growth Rate in Acidic Environment from Microorganisms Having L-glutamic Acid Resistance

The various microorganisms having L-glutamic acid resistance in an acidic environment obtained as described above were each inoculated into a test tube of 16.5 cm in length and 14 mm in diameter containing 3 mL of medium (adjusted to pH 4.0 with HCl) obtained by adding 20 g/L of glutamic acid and 2 g/L of glucose to M9 medium (Sambrook, J., Fritsh, E. F. and Maniatis, T., "Molecular Cloning", Cold Spring Harbor Laboratory Press, 1989), and the turbidity of the medium was measured in the time course to select strains with a favorable growth rate. As a result, as a strain showing favorable growth, the AJ13355 strain was obtained from a soil in Iwata-shi, Shizuoka, Japan. This strain was determined as .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.based on its bacteriological properties described above.

<3> Acquisition of Strain with Less Viscous Material Secretion from .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13355 Strain

Since the .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13355 strain extracellularly secretes a viscous material when cultured in a medium containing a saccharide, operation efficiency is not favorable. Therefore, a strain with less viscous material secretion was obtained by the ultraviolet irradiation method (Miller, J. H. et al., "A Short Course in Bacterial Genetics; Laboratory Manual", p. 150, Cold Spring Harbor Laboratory Press, 1992).

The .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13355 strain was irradiated with ultraviolet ray for 2 minutes at the position 60 cm away from a 60-W ultraviolet lamp and cultured in LB medium overnight to fix mutation. The mutagenized strain was diluted and inoculated in LB medium containing 5 g/L of glucose and 20 g/L of agar so that about 100 colonies per plate would emerge and cultured at 30.degree. C. overnight with tilting the plate about 45 degrees, and then 20 colonies showing no flowing down of the viscous material were selected.

As a strain satisfying conditions that no revertant emerged even after 5 times of subculture in LB medium containing 5 g/L of glucose and 20 g/L of agar, and that there should be observed growth equivalent to the parent strain in LB medium, LB medium containing 5 g/L of glucose and M9 medium (Sambrook, J. et al., Molecular Cloning, 2nd Edition, Cold Spring Harbor Press, 1989) to which 20 g/L of L-glutamic acid and 2 g/L of glucose were added and of which pH was adjusted to 4.5 with HCl, SC17 strain was selected from the strains selected above.

<4> Construction of Glutamic Acid-Producing Bacterium from .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.SC17 Strain

(1) Preparation of .alpha.KGDH Deficient Strain from .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.SC17 Strain

A strain deficient in .alpha.KGDH and with enhanced L-glutamic acid biosynthetic system was prepared from the .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.SC17 strain.

(i) Cloning of .alpha.KGDH Gene (Hereafter, Referred to as "sucAB") of .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13355 Strain

The sucAB gene of the .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13355 strain was cloned by selecting a DNA fragment complementing the acetic acid-unassimilating property of the .alpha.KGDH-E1 subunit gene (hereafter, referred to as "sucA") deficient strain of Escherichia coli from chromosomal DNA of the .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13355 strain.

The chromosomal DNA of the .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13355 strain was isolated by a method usually employed when chromosomal DNA is extracted from Escherichia coli (Text for Bioengineering Experiments, Edited by the Society for Bioscience and Bioengineering, Japan, pp. 97-98, Baifukan, 1992). The pTWV228 (resistant to ampicillin) used as a vector was commercially available one from Takara Shuzo Co., Ltd.

The chromosomal DNA of the AJ13355 strain digested with EcoT221 and pTWV228 digested with PstI were ligated by using T4 ligase and used to transform the sucA deficient Escherichia coli JRG465 strain (Herbert, J. et al., Mol. Gen. Genetics, 105, 182 (1969)). A strain growing in an acetate minimal medium was selected from the transformant strains obtained above, and a plasmid was extracted from it and designated as pTWVEK101. The Escherichia coil JRG465 strain harboring pTWVEK101 recovered auxotrophy for succinic acid or L-lysine and L-methionine besides the acetic acid-assimilating property. This suggests that pTWVEK101 contains the sucA gene of .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis.Iaddend..

FIG. 1 shows the restriction map of a DNA fragment derived from .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.in pTWVEK101. The determined nucleotide sequence of the hatched portion in FIG. 1 is shown as SEQ ID NO: 1. In this sequence, nucleotide sequences considered to be two full length ORFs and two nucleotide sequences considered to be partial sequences of the ORFs were found. SEQ ID NOS: 2 to 5 show amino acid sequences that can be encoded by these ORFs or partial sequences in an order from the 5' end. As a result of homology search for these, it was revealed that the portion of which nucleotide sequences were determined contained a 3'-end partial sequence of the succinate dehydrogenase iron-sulfur protein gene (sdhB), full length sucA and .alpha.KGDH-E2 subunit gene (sucB), and 5'-end partial sequence of the succinyl CoA synthetase .beta. subunit gene (sucC). The results of comparison of the amino acid sequences deduced from these nucleotide sequences with those derived from Escherichia coli (Eur. J. Biochem., 141, pp. 351-359 (1984); Eur. J. Biochem., 141, pp. 361-374 (1984); Biochemistry, 24, pp. 6245-6252 (1985)) are shown in FIGS. 2 to 5. Thus, the amino acid sequences each showed very high homology. In addition, it was found that a cluster of sdhB-sucA-sucB-sucC was constituted on the chromosome of .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.as in Escherichia coli is (Eur. J. Biochem., 141, pp. 351-359 (1984); Eur. J. Biochem., 141, pp. 361-374 (1984); Biochemistry, 24, pp. 6245-6252 (1985)).

(ii) Acquisition of .alpha.KGDH Deficient Strain Derived from .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.SC17 Strain

The homologous recombination was performed by using the sucAB gene of .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.obtained as described above to obtain an .alpha.KGDH deficient strain of .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis.Iaddend..

After pTWVEK101 was digested with SphI to excise a fragment containing sucA, the fragment was blunt-ended with Klenow fragment (Takara Shuzo Co., Ltd.) and ligated with pBR322 digested with EcoRI and blunt-ended with Klenow fragment, by using T4 DNA ligase (Takara Shuzo Co., Ltd.) The obtained plasmid was digested at the restriction enzyme BglII recognition site positioned substantially at the center of sucA by using this enzyme, blunt-ended with Klenow fragment, and then ligated again by using T4 DNA ligase. It was considered that the sucA gene did not function because a frame shift mutation was introduced into sucA of the plasmid newly constructed through the above procedure.

The plasmid constructed as described above was digested with a restriction enzyme ApaLI, and subjected to agarose gel electrophoresis to recover a DNA fragment containing sucA into which the frame shift mutation was introduced and a tetracycline resistance gene derived from pBR322. The recovered DNA fragment was ligated again by using T4 DNA ligase to construct a plasmid for disrupting the .alpha.KGDH gene.

The plasmid for disrupting the .alpha.KGDH gene obtained as described above was used to transform the .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.SC17 strain by electroporation (Miller, J. H., "A Short Course in Bacterial Genetics; Handbook", p. 279, Cold Spring Harbor Laboratory Press, U.S.A., 1992), and a strain where in sucA on the chromosome was replaced with a mutant type one by homologous recombination of the plasmid was obtained by using the tetracycline resistance as an indicator. The obtained strain was designated as SC17sucA strain.

In order to confirm that the SC17sucA strain was deficient in the .alpha.KGDH activity, the enzyme activity was measured by the method of Reed et al. (Reed, L. J. and Mukherjee, B. B., Methods in Enzymology, 13, pp. 55-61, (1969)) by using cells of the strain cultured in LB medium until the logarithmic growth phase. As a result, .alpha.KGDH activity of 0.073 (.DELTA.ABS/min/mg protein) was detected from the SC17 strain, whereas no .alpha.KGDH activity was detected from the SC17sucA strain, and thus it was confirmed that the sucA was deficient as purposed.

(2) Enhancement of L-Glutamic Acid Biosynthetic System of .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.SC17sucA Strain

Subsequently, a citrate synthase gene, a phosphoenolpyruvate carboxylase gene and a glutamate dehydrogenase gene derived from Escherichia coli were introduced into the SC17sucA strain.

(i) Preparation of Plasmid Having gltA Gene, ppc Gene and gdhA Gene Derived from Escherichia coli

The procedures of preparing a plasmid having a gltA gene, a ppc gene and a gdhA gene will be explained by referring to FIGS. 6 and 7.

A plasmid having a gdhA gene derived from Escherichia coli, pBRGDH (Japanese Patent Application Laid-open No. 7-203980), was digested with HindIII and SphI, the both ends were blunt-ended by the T4 DNA polymerase treatment, and then the DNA fragment having the gdhA gene was purified and recovered. Separately, a plasmid having a gltA gene and a ppc gene derived from Escherichia coli, pMWCP (WO 97/08294), was digested with XbaI, and then the both ends were blunt-ended by using T4 DNA polymerase. This was mixed with the above purified DNA fragment having the gdhA gene and ligated by using T4 ligase to obtain a plasmid pMWCPG, which corresponded to pMWCP further containing the gdhA gene (FIG. 6).

At the same time, the plasmid pVIC40 (Japanese Patent Application Laid-open No. 8-047397) having the replication origin of the broad host spectrum plasmid RSF1010 was digested with NotI, treated with T4 DNA polymerase and digested with PstI. pBR322 was digested with EcoT14I, treated with T4 DNA polymerase and digested with PstI. The both products were mixed and ligated by using T4 ligase to obtain a plasmid RSF-Tet having the replication origin of RSF1010 and a tetracycline resistance gene (FIG. 7).

Subsequently, pMWCPG was digested with EcoRI and PstI, and a DNA fragment having the gltA gene, the ppc gene and the gdhA gene was purified and recovered. RSF-Tet was similarly digested with EcoRI and PstI, and a DNA fragment having the replication origin of RSF1010 was purified and recovered. The both products were mixed and ligated by using T4 ligase to obtain a plasmid RSFCPG, which corresponded to RSF-Tet containing the gltA gene, the ppc gene and the gdhA gene (FIG. 8). It was confirmed that the obtained plasmid RSFCPG expressed the gltA gene, the ppc gene and the gdhA gene, by the complementation of the auxotrophy of the gltA, ppc or gdhA gene deficient strain derived from Escherichia coli and measurement of each enzyme activity.

(ii) Preparation of Plasmid Having gltA Gene Derived from Brevibacterium lactofermentum

A plasmid having the gltA gene derived from Brevibacterium lactofermentum was constructed as follows. PCR was performed by using the primer DNAs having the nucleotide sequences represented by SEQ ID NOS: 6 and 7, which were prepared based on the nucleotide sequence of the Corynebacterium glutamicum gltA gene (Microbiology, 140, pp. 1817-1828 (1994)), and chromosomal DNA of Brevibacterium lactofermentum ATCC13869 as a template to obtain a gltA gene fragment of about 3 kb. This fragment inserted into a plasmid pHSG399 (purchased from Takara Shuzo Co., Ltd.) digested with SmaI to obtain a plasmid pHSGCB (FIG. 9). Subsequently, pHSGCB was digested with HindIII, and the excised gltA gene fragment of about 3 kb was inserted into a plasmid pSTV29 (purchased from Takara Shuzo Co., Ltd.) digested with HindIII to obtain a plasmid pSTVCB (FIG. 9). It was confirmed that the obtained plasmid pSTVCB expressed the gltA gene, by measuring the enzyme activity in the .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13355 strain.

(iii) Introduction of RSFCPG and pSTVCB into SC17sucA Strain

The .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.SC17sucA strain was transformed with RSFCPG by electroporation to obtain a transformant SC17sucA/RSFCPG strain having tetracycline resistance. Further, the SC17sucA/RSFCPG strain was transformed with pSTVCB by electroporation to obtain a transformant SC17sucA/RSFCPG+pSTVCB strain having chloramphenicol resistance.

<4> Acquisition of Strain with Improved Resistance to L-Glutamic Acid in Low pH Environment

A strain with improved resistance to L-glutamic acid at a high concentration in a low pH environment (hereafter, also referred to as "high-concentration Glu-resistant strain at low pH") was isolated from the .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.SC17sucA/RSFCPG+pSTVCB strain.

The SC17sucA/RSFCPG+pSTVCB strain was cultured overnight at 30.degree. C. in LBG medium (10 g/L of tryptone, 5 g/L of yeast extract, 10 g/L of NaCl, 5 g/L of glucose), and the cells washed with saline was appropriately diluted and plated on an M9-E medium (4 g/L of glucose, 17 g/L of Na.sub.2HPO.sub.4.12H.sub.2O, 3 g/L of KH.sub.2PO.sub.4, 0.5 g/L of NaCl, 1 g/L of NH.sub.4Cl, 10 mM of MgSO.sub.4, 10 .mu.M of CaCl.sub.2, 50 mg/L of L-lysine, 50 mg/L of L-methionine, 50 mg/L of DL-diaminopimelic acid, 25 mg/L of tetracycline, 25 mg/L of chloramphenicol, 30 g/L of L-glutamic acid, adjusted to pH 4.5 with aqueous ammonia) plate. The colony emerged after culture a 32.degree. C. for 2 days was obtained as a high-concentration Glu-resistant strain at low pH.

For the obtained strain, growth level in M9-E liquid medium was measured and L-glutamic acid-producing ability was tested in a 50-ml volume large test tube containing 5 ml of L-glutamic acid production test medium (40 g/L of glucose, 20 g/L of (NH.sub.4).sub.2SO.sub.4, 0.5 g/L of MgSO.sub.4.7H.sub.2O, 2 g/L of KH.sub.2PO.sub.4, 0.5 g/L of NaCl, 0.25 g/L of CaCl.sub.2.7H.sub.2O, 0.02 g/L of FeSO.sub.4.7H.sub.2O, 0.02 g/L of MnSO.sub.4.4H.sub.2O, 0.72 mg/L of ZnSO.sub.4.2H.sub.2O, 0.64 mg/L of CuSO.sub.4.5H.sub.2O, 0.72 mg/L of CoCl.sub.2.6H.sub.2O, 0.4 mg/L of boric acid, 1.2 mg/L of Na.sub.2MoO.sub.4.2H.sub.2O, 2 g/L of yeast extract, 200 mg/L of L-lysine hydrochloride, 200 mg/L of L-methionine, 200 mg/L of DL-.alpha.,.epsilon.-diaminopimelic acid, 25 mg/L of tetracycline hydrochloride, 25 mg/L of chloramphenicol). A strain that exhibited the best growth level and the same L-glutamic acid producing ability as that of its parent strain, the SC17/RSFCPG+pSTVCB strain, was designated as .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13601. The AJ13601 strain was deposited at the National Institute of Bioscience and Human-Technology, Agency of Industrial Science and Technology, Ministry of International Trade and Industry (postal code: 305-8566, 1-3, Higashi 1-chome, Tsukuba-shi, Ibaraki, Japan) on Aug. 18, 1999 and received an accession number of FERM P-17516. It was then transferred to an international deposition under the provisions of Budapest Treaty on Jul. 6, 2000 and received an accession number of FERM BP-7207.

<5> Culture of .[.Enterobacter Agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13601 Strain for L-Glutamic Acid Production (1)

The .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13601 strain was inoculated into a 1-L jar fermenter containing 300 ml of medium containing 40 g/L of glucose, 20 g/L of (NH.sub.4).sub.2SO.sub.4, 0.5 g/L of MgSO.sub.4.7H.sub.2O, 2 g/L of KH.sub.2PO.sub.4, 0.5 g/L of NaCl, 0.25 g/L of CaCl.sub.2.7H.sub.2O, 0.02 g/L of FeSO.sub.4.7H.sub.2O, 0.02 g/L of MnSO.sub.4.4H.sub.2O, 0.72 mg/L of ZnSO.sub.4.2H.sub.2O, 0.64 mg/L of CuSO.sub.4.5H.sub.2O, 0.72 mg/L of CoCl.sub.2.6H.sub.2O, 0.4 mg/L of boric acid, 1.2 mg/L of Na.sub.2MoO.sub.4.2H.sub.2O, 2 g/L of yeast extract, 200 mg/L of L-lysine hydrochloride, 200 mg/L of L-methionine, 200 mg/L of DL-.alpha.,.epsilon.-diaminopimelic acid, 25 mg/L of tetracycline hydrochloride and 25 mg/L of chloramphenicol, and cultured at 34.degree. C. and pH 6.0 for 14 hours. The culture pH was controlled by introducing ammonia gas into the medium.

The culture obtained as described above was centrifuged at 5000 rpm for 10 minutes, and the collected cells were inoculated into a 1-L jar fermenter containing 300 ml of medium containing 40 g/L of glucose, 5 g/L of (NH.sub.4).sub.2SO.sub.4, 1.5 g/L of MgSO.sub.4.7H.sub.2O, 6 g/L of KH.sub.2PO.sub.4, 1.5 g/L of NaCl, 0.75 g/L of CaCl.sub.2.7H.sub.2O, 0.06 g/L of FeSO.sub.4.7H.sub.2O, 0.06 g/L of MnSO.sub.4.4H.sub.2O, 2.16 mg/L of ZnSO.sub.4.2H.sub.2O, 1.92 mg/L of CuSO.sub.4.5H.sub.2O, 2.16 mg/L of CoCl.sub.20.6H.sub.2O, 1.2 mg/L of boric acid, 3.6 mg/L of Na.sub.2MoO.sub.4.2H.sub.2O, 6 g/L of yeast extract, 600 mg/L of L-lysine hydrochloride, 600 mg/L of L-methionine, 600 mg/L of DL-.alpha.,.epsilon.-diaminopimelic acid, 25 mg/L of tetracycline hydrochloride and 25 mg/L of chloramphenicol and cultured at 34.degree. C. and pH 4.5 to perform culture for L-glutamic acid production. The culture pH was controlled by introducing ammonia gas into the medium. As the initially added glucose was depleted, 600 g/L of glucose was continuously added.

As a result of the culture for L-glutamic acid production performed for 50 hours as described above, a substantial amount of L-glutamic acid crystals were precipitated in the jar fermenter. Table 1 shows the concentration of L-glutamic acid dissolved in the culture broth at that time and the L-glutamic acid concentration measured by dissolving the crystals in 2 M potassium hydroxide. L-Glutamic acid crystals were collected from the culture by decantation after the culture was left stood.

TABLE-US-00001 TABLE 1 Concentration of L-glutamic acid 51 g/L dissolved in culture broth Amount of L-glutamic acid precipitated 67 g/L as crystals Concentration of L-glutamic acid 118 g/L measured by dissolving crystals

<6> Culture of .[.Enterobacter Agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13601 Strain for L-Glutamic Acid Production (2)

The following experiment was performed in order to confirm that the .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13601 strain still had L-glutamic acid-producing ability even under the condition that L-glutamic acid crystals were present.

The .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13601 strain was inoculated into a 1-L jar fermenter containing 300 ml of medium containing 40 g/L of glucose, 20 g/L of (NH.sub.4).sub.2SO.sub.4, 0.5 g/L of MgSO.sub.4.7H.sub.2O, 2 g/L of KH.sub.2PO.sub.4, 0.5 g/L of NaCl, 0.25 g/L of CaCl.sub.2.7H.sub.2O, 0.02 g/L of FeSO.sub.4.7H.sub.2O, 0.02 g/L of MnSO.sub.4.4H.sub.2O, 0.72 mg/L of ZnSO.sub.4.2H.sub.2O, 0.64 mg/L of CuSO.sub.4.5H.sub.2O, 0.72 mg/L of CoCl.sub.2.6H.sub.2O, 0.4 mg/L of boric acid, 1.2 mg/L of Na.sub.2MoO.sub.4.2H.sub.2O, 2 g/L of yeast extract, 200 mg/L of L-lysine hydrochloride, 200 mg/L of L-methionine, 200 mg/L of DL-.alpha.,.epsilon.-diaminopimelic acid, 25 mg/L of tetracycline hydrochloride and 25 mg/L of chloramphenicol, and cultured at 34.degree. C. at pH 6.0 for 14 hours. The culture pH was controlled by bubbling the medium with ammonia gas. The culture obtained as described above was centrifuged at 5000 rpm for 10 minutes, and then the collected cells were cultured in a medium where L-glutamic acid was present as crystals. The used medium contained 40 g/L of glucose, 5 g/L of (NH.sub.4).sub.2SO.sub.4, 1.5 g/L of MgSO.sub.4.7H.sub.2O, 6 g/L of KH.sub.2PO.sub.4, 1.5 g/L of NaCl, 0.75 g/L of CaCl.sub.2.7H.sub.2O, 0.06 g/L of FeSO.sub.4.7H.sub.2O, 0.06 g/L of MnSO.sub.4.4H.sub.2O, 2.16 mg/L of ZnSO.sub.4.2H.sub.2O, 1.92 mg/L of CuSO.sub.4.5H.sub.2O, 2.16 mg/L of CoCl.sub.2.6H.sub.2O, 1.2 mg/L of boric acid, 3.6 mg/L of Na.sub.2MoO.sub.4.2H.sub.2O, 6 g/L of yeast extract, 600 mg/L of L-lysine hydrochloride, 600 mg/L of L-methionine, 600 mg/L of DL-.alpha.,.epsilon.-diaminopimelic acid, 25 mg/L of tetracycline hydrochloride and 25 mg/L of chloramphenicol and L-glutamic acid crystals were added to 40 g/L. The cells were inoculated in a 1-L jar fermenter containing 300 ml of this medium and cultured at 34.degree. C. and pH 4.3 to perform culture for L-glutamic acid production. The culture pH was controlled by introducing ammonia gas into the medium. As the initially added glucose was depleted, 600 g/L of glucose was continuously added. In this medium, only 39 g/L of the added L-glutamic acid was dissolved at pH 4.3 and the remaining 1 g/L was present as crystals.

As a result of the culture for L-glutamic acid production performed for 53 hours as described above, a substantial amount of L-glutamic acid crystals were precipitated in the jar fermenter. Table 2 shows the concentration of L-glutamic acid dissolved in the culture broth, the amount of L-glutamic acid present as crystals at that time and the L-glutamic acid concentration measured by dissolving the crystals in 2MKOH solution. L-Glutamic acid crystals were collected from the culture by decantation after the culture was left stood. The results showed that the .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13101 strain accumulated L-glutamic acid and precipitated crystals thereof even under the condition that L-glutamic acid crystals were present.

TABLE-US-00002 TABLE 2 Concentration of L-glutamic acid 39 g/L dissolved in culture broth Amount of L-glutamic acid precipitated 119 g/L as crystals Concentration of L-glutamic acid 158 g/L measured by dissolving crystals Amount of L-glutamic acid crystals 118 g/L newly produced by main culture

<7> Culture of .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13601 Strain for L-Glutamic Acid Production (3)

The .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13601 strain can grow not only at an acidic pH, but also at a neutral pH. Therefore, it was confirmed as follows that L-glutamic acid crystals could also be precipitated by starting the culture at a neutral pH and allowing production of L-glutamic acid during the culture so that pH of the culture should spontaneously be lowered.

Cells of one plate (8.5 cm in diameter) of the .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis .Iaddend.AJ13601 strain, cultured on LBG agar medium (10 g/ of L tryptone, 5 g/L of yeast extract, 10 g/L of NaCl, 5 g/L of glucose, 15 g/L of agar) containing 25 mg/L of tetracycline hydrochloride and 25 mg/L of chloramphenicol at 30.degree. C. for 14 hours, were inoculated into a 1-L jar fermenter containing 300 ml of medium containing 40 g/L of glucose, 5 g/L of (NH.sub.4).sub.2SO.sub.4, 1.5 g/L of MgSO.sub.4.7H.sub.2O, 6 g/L of KH.sub.2PO.sub.4, 1.5 g/L of NaCl, 0.75 g/L of CaCl.sub.2.7H.sub.2O, 0.06 g/L of FeSO.sub.4.7H.sub.2O, 0.06 g/L of MnSO.sub.4.4H.sub.2O, 2.16 mg/L of ZnSO.sub.4.2H.sub.2O, 1.92 mg/L of CuSO.sub.4.5H.sub.2O, 2.16 mg/L of CoCl.sub.2.6H.sub.2O., 1.2 mg/L of boric acid, 3.6 mg/L of Na.sub.2MoO.sub.4.2H.sub.2O, 6 g/L of yeast extract, 600 mg/L of L-lysine hydrochloride, 600 mg/L of L-methionine, 600 mg/L of DL-.alpha.,.epsilon.-diaminopimelic acid, 25 mg/L of tetracycline hydrochloride and 25 mg/L of chloramphenicol and the culture was started at 34.degree. C. and pH 7.0. The culture pH was controlled by introducing ammonia gas into the medium. As the initially added glucose was depleted, 600 g/L of glucose was continuously added.

As L-glutamic acid is accumulated, pH lowers spontaneously. The amount of the introduced ammonia gas was adjusted so that pH should be gradually lowered from 7.0 to 4.5 during the period between 15 hours and 24 hours after the start of the culture, and 24 hours after the start of the culture, pH became 4.5. Afterward, cultivation was continued for 12 hours.

As a result of the culture for L-glutamic acid production conducted for 36 hours as described above, a substantial amount of L-glutamic acid crystals were precipitated in the jar fermenter. Table 3 shows the concentration of L-glutamic acid dissolved in the culture broth, the amount of L-glutamic acid present as crystals at that time and the L-glutamic acid concentration measured by dissolving the crystals in 2 MKOH solution. L-Glutamic acid crystals were collected from the culture by decantation after the culture was left stood.

TABLE-US-00003 TABLE 3 Concentration of L-glutamic acid 45 g/L dissolved in culture broth Amount of L-glutamic acid precipitated 31 g/L as crystals Concentration of L-glutamic acid 76 g/L measured by dissolving crystals

SEQUENCE LISTINGS

1

1214556DNAEnterobacter agglomeransCDS(2)..(121)CDS(322)..(3129)CDS(3145)..(4368)CDS(4437)..(4556- ) 1t gca ttc agc gtt ttc cgc tgt cac agc atc atg aac tgt gta agt gtt 49 Ala Phe Ser Val Phe Arg Cys His Ser Ile Met Asn Cys Val Ser Val 1 5 10 15tgt cct aaa ggg cta aac ccg acg cgc gct atc ggc cac att aag tcg 97Cys Pro Lys Gly Leu Asn Pro Thr Arg Ala Ile Gly His Ile Lys Ser 20 25 30atg ctg ctg caa cgc agc gcg tag ttataccacc gggaacctca ggttcccggt 151Met Leu Leu Gln Arg Ser Ala 35attttacgga agcctctgta aacgcggtcc caaccacgtt tacaaaggtt cccttacggg 211ccgggcgcgc gctgcgcaca gtgctcgtat cgctgaactc actacggcaa accgcgaaag 271cggcaacaaa tgaaacctca aaaaagcata acattgctta agggatcaca atg cag 327 Met Gln 40aac agc gcg atg aag ccc tgg ctg gac tcc tcc tgg ctg gcc ggc gcg 375Asn Ser Ala Met Lys Pro Trp Leu Asp Ser Ser Trp Leu Ala Gly Ala 45 50 55aat cag tct tac ata gag caa ctc tat gag gat ttc ctg acc gat cct 423Asn Gln Ser Tyr Ile Glu Gln Leu Tyr Glu Asp Phe Leu Thr Asp Pro 60 65 70gac tct gtg gat gca gtg tgg cgc tcg atg ttc caa cag tta cca ggc 471Asp Ser Val Asp Ala Val Trp Arg Ser Met Phe Gln Gln Leu Pro Gly 75 80 85acg gga gtg aaa cct gag cag ttc cac tcc gca act cgc gaa tat ttc 519Thr Gly Val Lys Pro Glu Gln Phe His Ser Ala Thr Arg Glu Tyr Phe90 95 100 105cgt cgc ctg gcg aaa gac gca tct cgt tac acc tcc tca gtt acc gat 567Arg Arg Leu Ala Lys Asp Ala Ser Arg Tyr Thr Ser Ser Val Thr Asp 110 115 120ccg gca acc aac tcc aaa caa gtg aaa gtg ctg cag ctg att aac gcg 615Pro Ala Thr Asn Ser Lys Gln Val Lys Val Leu Gln Leu Ile Asn Ala 125 130 135ttt cgt ttc cgc gga cat cag gaa gca aat ctc gat ccg ctt ggc ctg 663Phe Arg Phe Arg Gly His Gln Glu Ala Asn Leu Asp Pro Leu Gly Leu 140 145 150tgg aaa cag gac cgc gtt gcc gat ctc gat cct gcc ttt cac gat ctg 711Trp Lys Gln Asp Arg Val Ala Asp Leu Asp Pro Ala Phe His Asp Leu 155 160 165acc gac gcc gat ttt cag gaa agc ttt aac gta ggt tct ttt gcc att 759Thr Asp Ala Asp Phe Gln Glu Ser Phe Asn Val Gly Ser Phe Ala Ile170 175 180 185ggc aaa gaa acc atg aag ctg gcc gat ctg ttc gac gcg ctg aag cag 807Gly Lys Glu Thr Met Lys Leu Ala Asp Leu Phe Asp Ala Leu Lys Gln 190 195 200acc tac tgt ggc tcg att ggt gca gag tat atg cac atc aat aac acc 855Thr Tyr Cys Gly Ser Ile Gly Ala Glu Tyr Met His Ile Asn Asn Thr 205 210 215gaa gag aaa cgc tgg atc cag cag cgt atc gaa tcc ggt gcg agc cag 903Glu Glu Lys Arg Trp Ile Gln Gln Arg Ile Glu Ser Gly Ala Ser Gln 220 225 230acg tca ttc agt ggc gaa gag aaa aaa ggt ttc ctg aaa gag ctg acc 951Thr Ser Phe Ser Gly Glu Glu Lys Lys Gly Phe Leu Lys Glu Leu Thr 235 240 245gcg gca gaa ggg ctg gaa aaa tat ctg ggc gcg aaa ttc ccg ggt gca 999Ala Ala Glu Gly Leu Glu Lys Tyr Leu Gly Ala Lys Phe Pro Gly Ala250 255 260 265aaa cgt ttc tcg ctg gaa ggc ggt gat gcg ctg gtg ccg atg ctg cgc 1047Lys Arg Phe Ser Leu Glu Gly Gly Asp Ala Leu Val Pro Met Leu Arg 270 275 280gag atg att cgt cat gcg ggc aaa agc ggc aca cgt gaa gtg gta ctg 1095Glu Met Ile Arg His Ala Gly Lys Ser Gly Thr Arg Glu Val Val Leu 285 290 295ggg atg gcg cac cgt ggc cgt ctt aac gta ctg att aac gta ctg ggt 1143Gly Met Ala His Arg Gly Arg Leu Asn Val Leu Ile Asn Val Leu Gly 300 305 310aaa aag cca cag gat ctg ttc gac gaa ttc tcc ggt aaa cac aaa gag 1191Lys Lys Pro Gln Asp Leu Phe Asp Glu Phe Ser Gly Lys His Lys Glu 315 320 325cat ctg ggc acc ggt gat gtg aag tat cac atg ggc ttc tct tcg gat 1239His Leu Gly Thr Gly Asp Val Lys Tyr His Met Gly Phe Ser Ser Asp330 335 340 345att gaa acc gaa ggt ggt ctg gtg cat ctg gcg ctg gcg ttt aac ccg 1287Ile Glu Thr Glu Gly Gly Leu Val His Leu Ala Leu Ala Phe Asn Pro 350 355 360tct cac ctg gaa att gtc agc ccg gtg gtc atg gga tcg gta cgt gca 1335Ser His Leu Glu Ile Val Ser Pro Val Val Met Gly Ser Val Arg Ala 365 370 375cgt ctc gat cgt ctg gcc gaa ccg gtc agc aat aaa gtg ttg cct atc 1383Arg Leu Asp Arg Leu Ala Glu Pro Val Ser Asn Lys Val Leu Pro Ile 380 385 390acc att cac ggt gat gcg gcg gtg att ggt cag ggc gtg gtt cag gaa 1431Thr Ile His Gly Asp Ala Ala Val Ile Gly Gln Gly Val Val Gln Glu 395 400 405acc ctg aac atg tct cag gcg cgc ggc tac gaa gtg ggc ggc acg gta 1479Thr Leu Asn Met Ser Gln Ala Arg Gly Tyr Glu Val Gly Gly Thr Val410 415 420 425cgt atc gtc att aac aac cag gtt ggt ttt acc acc tcc aac ccg aaa 1527Arg Ile Val Ile Asn Asn Gln Val Gly Phe Thr Thr Ser Asn Pro Lys 430 435 440gat gcg cgt tca acc ccg tac tgt act gac atc ggc aag atg gtg ctg 1575Asp Ala Arg Ser Thr Pro Tyr Cys Thr Asp Ile Gly Lys Met Val Leu 445 450 455gca ccg att ttc cac gtc aat gct gac gat ccg gaa gcg gtg gcc ttt 1623Ala Pro Ile Phe His Val Asn Ala Asp Asp Pro Glu Ala Val Ala Phe 460 465 470gtt acc cgc ctg gcg ctg gac tat cgc aac acc ttc aaa cgc gat gtg 1671Val Thr Arg Leu Ala Leu Asp Tyr Arg Asn Thr Phe Lys Arg Asp Val 475 480 485ttt atc gat ctg gtg tgc tat cgc cgt cat ggt cac aac gag gcg gat 1719Phe Ile Asp Leu Val Cys Tyr Arg Arg His Gly His Asn Glu Ala Asp490 495 500 505gag cca agt gct acc cag ccg ttg atg tac cag aaa atc aaa aag cat 1767Glu Pro Ser Ala Thr Gln Pro Leu Met Tyr Gln Lys Ile Lys Lys His 510 515 520ccg acg ccg cgt aaa att tac gcc gat cgt ctg gaa ggc gaa ggt gtc 1815Pro Thr Pro Arg Lys Ile Tyr Ala Asp Arg Leu Glu Gly Glu Gly Val 525 530 535gcg tcg cag gaa gat gcc acc gag atg gtg aac ctg tac cgc gat gcg 1863Ala Ser Gln Glu Asp Ala Thr Glu Met Val Asn Leu Tyr Arg Asp Ala 540 545 550ctc gat gcg ggc gaa tgc gtg gtg ccg gaa tgg cgt ccg atg agc ctg 1911Leu Asp Ala Gly Glu Cys Val Val Pro Glu Trp Arg Pro Met Ser Leu 555 560 565cac tcc ttc acg tgg tcg cct tat ctg aac cac gaa tgg gat gag cct 1959His Ser Phe Thr Trp Ser Pro Tyr Leu Asn His Glu Trp Asp Glu Pro570 575 580 585tat ccg gca cag gtt gac atg aaa cgc ctg aag gaa ctg gca ttg cgt 2007Tyr Pro Ala Gln Val Asp Met Lys Arg Leu Lys Glu Leu Ala Leu Arg 590 595 600atc agc cag gtc cct gag cag att gaa gtg cag tcg cgc gtg gcc aag 2055Ile Ser Gln Val Pro Glu Gln Ile Glu Val Gln Ser Arg Val Ala Lys 605 610 615atc tat aac gat cgc aag ctg atg gcc gaa ggc gag aaa gcg ttc gac 2103Ile Tyr Asn Asp Arg Lys Leu Met Ala Glu Gly Glu Lys Ala Phe Asp 620 625 630tgg ggc ggt gcc gag aat ctg gcg tac gcc acg ctg gtg gat gaa ggt 2151Trp Gly Gly Ala Glu Asn Leu Ala Tyr Ala Thr Leu Val Asp Glu Gly 635 640 645att ccg gtt cgc ctc tcg ggt gaa gac tcc ggt cgt gga acc ttc ttc 2199Ile Pro Val Arg Leu Ser Gly Glu Asp Ser Gly Arg Gly Thr Phe Phe650 655 660 665cat cgc cac gcg gtc gtg cac aac cag gct aac ggt tca acc tat acg 2247His Arg His Ala Val Val His Asn Gln Ala Asn Gly Ser Thr Tyr Thr 670 675 680ccg ctg cac cat att cat aac agc cag ggc gag ttc aaa gtc tgg gat 2295Pro Leu His His Ile His Asn Ser Gln Gly Glu Phe Lys Val Trp Asp 685 690 695tcg gtg ctg tct gaa gaa gcg gtg ctg gcg ttt gaa tac ggt tac gcc 2343Ser Val Leu Ser Glu Glu Ala Val Leu Ala Phe Glu Tyr Gly Tyr Ala 700 705 710acg gct gag ccg cgc gtg ctg acc atc tgg gaa gcg cag ttt ggt gac 2391Thr Ala Glu Pro Arg Val Leu Thr Ile Trp Glu Ala Gln Phe Gly Asp 715 720 725ttt gcc aac ggt gct cag gtg gtg att gac cag ttc atc agc tct ggc 2439Phe Ala Asn Gly Ala Gln Val Val Ile Asp Gln Phe Ile Ser Ser Gly730 735 740 745gaa cag aag tgg ggc cgt atg tgt ggc ctg gtg atg ttg ctg ccg cat 2487Glu Gln Lys Trp Gly Arg Met Cys Gly Leu Val Met Leu Leu Pro His 750 755 760ggc tac gaa ggt cag gga ccg gaa cac tcc tct gcc cgt ctg gaa cgc 2535Gly Tyr Glu Gly Gln Gly Pro Glu His Ser Ser Ala Arg Leu Glu Arg 765 770 775tat ctg caa ctt tgc gcc gag cag aac atg cag gtt tgc gtc ccg tcg 2583Tyr Leu Gln Leu Cys Ala Glu Gln Asn Met Gln Val Cys Val Pro Ser 780 785 790acg ccg gct cag gtg tat cac atg ctg cgc cgt cag gcg ctg cgc ggg 2631Thr Pro Ala Gln Val Tyr His Met Leu Arg Arg Gln Ala Leu Arg Gly 795 800 805atg cgc cgt ccg ctg gtg gtg atg tcg ccg aag tcg ctg tta cgc cat 2679Met Arg Arg Pro Leu Val Val Met Ser Pro Lys Ser Leu Leu Arg His810 815 820 825cca ctg gcg atc tcg tcg ctg gat gaa ctg gca aac ggc agt ttc cag 2727Pro Leu Ala Ile Ser Ser Leu Asp Glu Leu Ala Asn Gly Ser Phe Gln 830 835 840ccg gcc att ggt gag atc gac gat ctg gat ccg cag ggc gtg aaa cgc 2775Pro Ala Ile Gly Glu Ile Asp Asp Leu Asp Pro Gln Gly Val Lys Arg 845 850 855gtc gtg ctg tgc tcc ggt aag gtt tac tac gat ctg ctg gaa cag cgt 2823Val Val Leu Cys Ser Gly Lys Val Tyr Tyr Asp Leu Leu Glu Gln Arg 860 865 870cgt aaa gac gag aaa acc gat gtt gcc atc gtg cgc atc gaa cag ctt 2871Arg Lys Asp Glu Lys Thr Asp Val Ala Ile Val Arg Ile Glu Gln Leu 875 880 885tac ccg ttc ccg cat cag gcg gta cag gaa gca ttg aaa gcc tat tct 2919Tyr Pro Phe Pro His Gln Ala Val Gln Glu Ala Leu Lys Ala Tyr Ser890 895 900 905cac gta cag gac ttt gtc tgg tgc cag gaa gag cct ctg aac cag ggc 2967His Val Gln Asp Phe Val Trp Cys Gln Glu Glu Pro Leu Asn Gln Gly 910 915 920gcc tgg tac tgt agc cag cat cat ttc cgt gat gtc gtg ccg ttt ggt 3015Ala Trp Tyr Cys Ser Gln His His Phe Arg Asp Val Val Pro Phe Gly 925 930 935gcc acc ctg cgt tat gca ggt cgc ccg gca tcg gct tct ccg gcc gtg 3063Ala Thr Leu Arg Tyr Ala Gly Arg Pro Ala Ser Ala Ser Pro Ala Val 940 945 950ggt tat atg tcc gta cac caa caa cag cag caa gac ctg gtt aat gac 3111Gly Tyr Met Ser Val His Gln Gln Gln Gln Gln Asp Leu Val Asn Asp 955 960 965gca ctg aac gtc aat taa ttaaaaggaa agata atg agt agc gta gat att 3162Ala Leu Asn Val Asn Met Ser Ser Val Asp Ile970 975 980ctc gtt ccc gac ctg cct gaa tcg gtt gca gat gcc aca gta gca acc 3210Leu Val Pro Asp Leu Pro Glu Ser Val Ala Asp Ala Thr Val Ala Thr 985 990 995tgg cac aag aaa cca ggc gat gca gtc agc cgc gat gaa gtc atc 3255Trp His Lys Lys Pro Gly Asp Ala Val Ser Arg Asp Glu Val Ile 1000 1005 1010gtc gaa att gaa act gac aaa gtc gtg ctg gaa gtg ccg gca tct 3300Val Glu Ile Glu Thr Asp Lys Val Val Leu Glu Val Pro Ala Ser 1015 1020 1025gcc gat ggc gtg ctg gaa gcc gtg ctg gaa gac gaa ggg gca acc 3345Ala Asp Gly Val Leu Glu Ala Val Leu Glu Asp Glu Gly Ala Thr 1030 1035 1040gtt acg tcc cgc cag atc ctg ggt cgc ctg aaa gaa ggc aac agt 3390Val Thr Ser Arg Gln Ile Leu Gly Arg Leu Lys Glu Gly Asn Ser 1045 1050 1055gcg ggt aaa gaa agc agt gcc aaa gcg gaa agc aat gac acc acg 3435Ala Gly Lys Glu Ser Ser Ala Lys Ala Glu Ser Asn Asp Thr Thr 1060 1065 1070cca gcc cag cgt cag aca gcg tcg ctt gaa gaa gag agc agc gat 3480Pro Ala Gln Arg Gln Thr Ala Ser Leu Glu Glu Glu Ser Ser Asp 1075 1080 1085gcg ctc agc ccg gcg atc cgt cgc ctg att gcg gag cat aat ctt 3525Ala Leu Ser Pro Ala Ile Arg Arg Leu Ile Ala Glu His Asn Leu 1090 1095 1100gac gct gcg cag atc aaa ggc acc ggc gta ggc gga cgt tta acg 3570Asp Ala Ala Gln Ile Lys Gly Thr Gly Val Gly Gly Arg Leu Thr 1105 1110 1115cgt gaa gac gtt gaa aaa cat ctg gcg aac aaa ccg cag gct gag 3615Arg Glu Asp Val Glu Lys His Leu Ala Asn Lys Pro Gln Ala Glu 1120 1125 1130aaa gcc gcc gcg cca gcg gcg ggt gca gca acg gct cag cag cct 3660Lys Ala Ala Ala Pro Ala Ala Gly Ala Ala Thr Ala Gln Gln Pro 1135 1140 1145gtt gcc aac cgc agc gaa aaa cgt gtt ccg atg acg cgt tta cgt 3705Val Ala Asn Arg Ser Glu Lys Arg Val Pro Met Thr Arg Leu Arg 1150 1155 1160aag cgc gtc gcg gag cgt ctg ctg gaa gcc aag aac agc acc gcc 3750Lys Arg Val Ala Glu Arg Leu Leu Glu Ala Lys Asn Ser Thr Ala 1165 1170 1175atg ttg acg acc ttc aac gaa atc aac atg aag ccg att atg gat 3795Met Leu Thr Thr Phe Asn Glu Ile Asn Met Lys Pro Ile Met Asp 1180 1185 1190ctg cgt aag cag tac ggc gat gcg ttc gag aag cgt cac ggt gtg 3840Leu Arg Lys Gln Tyr Gly Asp Ala Phe Glu Lys Arg His Gly Val 1195 1200 1205cgt ctg ggc ttt atg tct ttc tac atc aag gcc gtg gtc gaa gcg 3885Arg Leu Gly Phe Met Ser Phe Tyr Ile Lys Ala Val Val Glu Ala 1210 1215 1220ctg aag cgt tat cca gaa gtc aac gcc tct atc gat ggc gaa gac 3930Leu Lys Arg Tyr Pro Glu Val Asn Ala Ser Ile Asp Gly Glu Asp 1225 1230 1235gtg gtg tac cac aac tat ttc gat gtg agt att gcc gtc tct acg 3975Val Val Tyr His Asn Tyr Phe Asp Val Ser Ile Ala Val Ser Thr 1240 1245 1250cca cgc gga ctg gtg acg cct gtc ctg cgt gac gtt gat gcg ctg 4020Pro Arg Gly Leu Val Thr Pro Val Leu Arg Asp Val Asp Ala Leu 1255 1260 1265agc atg gct gac atc gag aag aaa att aaa gaa ctg gca gtg aaa 4065Ser Met Ala Asp Ile Glu Lys Lys Ile Lys Glu Leu Ala Val Lys 1270 1275 1280ggc cgt gac ggc aag ctg acg gtt gac gat ctg acg ggc ggt aac 4110Gly Arg Asp Gly Lys Leu Thr Val Asp Asp Leu Thr Gly Gly Asn 1285 1290 1295ttt acc atc acc aac ggt ggt gtg ttc ggt tcg ctg atg tct acg 4155Phe Thr Ile Thr Asn Gly Gly Val Phe Gly Ser Leu Met Ser Thr 1300 1305 1310cca atc atc aac ccg cca cag agc gcg att ctg ggc atg cac gcc 4200Pro Ile Ile Asn Pro Pro Gln Ser Ala Ile Leu Gly Met His Ala 1315 1320 1325att aaa gat cgt cct atg gcg gtc aat ggt cag gtt gtg atc ctg 4245Ile Lys Asp Arg Pro Met Ala Val Asn Gly Gln Val Val Ile Leu 1330 1335 1340cca atg atg tac ctg gct ctc tcc tac gat cac cgt tta atc gat 4290Pro Met Met Tyr Leu Ala Leu Ser Tyr Asp His Arg Leu Ile Asp 1345 1350 1355ggt cgt gaa tct gtc ggc tat ctg gtc gcg gtg aaa gag atg ctg 4335Gly Arg Glu Ser Val Gly Tyr Leu Val Ala Val Lys Glu Met Leu 1360 1365 1370gaa gat ccg gcg cgt ctg ctg ctg gat gtc tga ttcatcactg 4378Glu Asp Pro Ala Arg Leu Leu Leu Asp Val 1375 1380ggcacgcgtt gcgtgcccaa tctcaatact cttttcagat ctgaatggat agaacatc 4436atg aac tta cac gaa tac cag gct aaa cag ctg ttt gca cgg tat 4481Met Asn Leu His Glu Tyr Gln Ala Lys Gln Leu Phe Ala Arg Tyr 1385 1390 1395ggc atg cca gca ccg acc ggc tac gcc tgt act aca cca cgt gaa 4526Gly Met Pro Ala Pro Thr Gly Tyr Ala Cys Thr Thr Pro Arg Glu 1400 1405 1410gca gaa gaa gcg gca tcg aaa atc ggt gca 4556Ala Glu Glu Ala Ala Ser Lys Ile Gly Ala 1415 1420239PRTEnterobacter agglomerans 2Ala Phe Ser Val Phe Arg Cys His Ser Ile Met Asn Cys Val Ser Val1 5 10 15Cys Pro Lys Gly Leu Asn Pro Thr Arg Ala Ile Gly His Ile Lys Ser 20 25 30Met Leu Leu Gln

Arg Ser Ala 353935PRTEnterobacter agglomerans 3Met Gln Asn Ser Ala Met Lys Pro Trp Leu Asp Ser Ser Trp Leu Ala1 5 10 15Gly Ala Asn Gln Ser Tyr Ile Glu Gln Leu Tyr Glu Asp Phe Leu Thr 20 25 30Asp Pro Asp Ser Val Asp Ala Val Trp Arg Ser Met Phe Gln Gln Leu 35 40 45Pro Gly Thr Gly Val Lys Pro Glu Gln Phe His Ser Ala Thr Arg Glu 50 55 60Tyr Phe Arg Arg Leu Ala Lys Asp Ala Ser Arg Tyr Thr Ser Ser Val65 70 75 80Thr Asp Pro Ala Thr Asn Ser Lys Gln Val Lys Val Leu Gln Leu Ile 85 90 95Asn Ala Phe Arg Phe Arg Gly His Gln Glu Ala Asn Leu Asp Pro Leu 100 105 110Gly Leu Trp Lys Gln Asp Arg Val Ala Asp Leu Asp Pro Ala Phe His 115 120 125Asp Leu Thr Asp Ala Asp Phe Gln Glu Ser Phe Asn Val Gly Ser Phe 130 135 140Ala Ile Gly Lys Glu Thr Met Lys Leu Ala Asp Leu Phe Asp Ala Leu145 150 155 160Lys Gln Thr Tyr Cys Gly Ser Ile Gly Ala Glu Tyr Met His Ile Asn 165 170 175Asn Thr Glu Glu Lys Arg Trp Ile Gln Gln Arg Ile Glu Ser Gly Ala 180 185 190Ser Gln Thr Ser Phe Ser Gly Glu Glu Lys Lys Gly Phe Leu Lys Glu 195 200 205Leu Thr Ala Ala Glu Gly Leu Glu Lys Tyr Leu Gly Ala Lys Phe Pro 210 215 220Gly Ala Lys Arg Phe Ser Leu Glu Gly Gly Asp Ala Leu Val Pro Met225 230 235 240Leu Arg Glu Met Ile Arg His Ala Gly Lys Ser Gly Thr Arg Glu Val 245 250 255Val Leu Gly Met Ala His Arg Gly Arg Leu Asn Val Leu Ile Asn Val 260 265 270Leu Gly Lys Lys Pro Gln Asp Leu Phe Asp Glu Phe Ser Gly Lys His 275 280 285Lys Glu His Leu Gly Thr Gly Asp Val Lys Tyr His Met Gly Phe Ser 290 295 300Ser Asp Ile Glu Thr Glu Gly Gly Leu Val His Leu Ala Leu Ala Phe305 310 315 320Asn Pro Ser His Leu Glu Ile Val Ser Pro Val Val Met Gly Ser Val 325 330 335Arg Ala Arg Leu Asp Arg Leu Ala Glu Pro Val Ser Asn Lys Val Leu 340 345 350Pro Ile Thr Ile His Gly Asp Ala Ala Val Ile Gly Gln Gly Val Val 355 360 365Gln Glu Thr Leu Asn Met Ser Gln Ala Arg Gly Tyr Glu Val Gly Gly 370 375 380Thr Val Arg Ile Val Ile Asn Asn Gln Val Gly Phe Thr Thr Ser Asn385 390 395 400Pro Lys Asp Ala Arg Ser Thr Pro Tyr Cys Thr Asp Ile Gly Lys Met 405 410 415Val Leu Ala Pro Ile Phe His Val Asn Ala Asp Asp Pro Glu Ala Val 420 425 430Ala Phe Val Thr Arg Leu Ala Leu Asp Tyr Arg Asn Thr Phe Lys Arg 435 440 445Asp Val Phe Ile Asp Leu Val Cys Tyr Arg Arg His Gly His Asn Glu 450 455 460Ala Asp Glu Pro Ser Ala Thr Gln Pro Leu Met Tyr Gln Lys Ile Lys465 470 475 480Lys His Pro Thr Pro Arg Lys Ile Tyr Ala Asp Arg Leu Glu Gly Glu 485 490 495Gly Val Ala Ser Gln Glu Asp Ala Thr Glu Met Val Asn Leu Tyr Arg 500 505 510Asp Ala Leu Asp Ala Gly Glu Cys Val Val Pro Glu Trp Arg Pro Met 515 520 525Ser Leu His Ser Phe Thr Trp Ser Pro Tyr Leu Asn His Glu Trp Asp 530 535 540Glu Pro Tyr Pro Ala Gln Val Asp Met Lys Arg Leu Lys Glu Leu Ala545 550 555 560Leu Arg Ile Ser Gln Val Pro Glu Gln Ile Glu Val Gln Ser Arg Val 565 570 575Ala Lys Ile Tyr Asn Asp Arg Lys Leu Met Ala Glu Gly Glu Lys Ala 580 585 590Phe Asp Trp Gly Gly Ala Glu Asn Leu Ala Tyr Ala Thr Leu Val Asp 595 600 605Glu Gly Ile Pro Val Arg Leu Ser Gly Glu Asp Ser Gly Arg Gly Thr 610 615 620Phe Phe His Arg His Ala Val Val His Asn Gln Ala Asn Gly Ser Thr625 630 635 640Tyr Thr Pro Leu His His Ile His Asn Ser Gln Gly Glu Phe Lys Val 645 650 655Trp Asp Ser Val Leu Ser Glu Glu Ala Val Leu Ala Phe Glu Tyr Gly 660 665 670Tyr Ala Thr Ala Glu Pro Arg Val Leu Thr Ile Trp Glu Ala Gln Phe 675 680 685Gly Asp Phe Ala Asn Gly Ala Gln Val Val Ile Asp Gln Phe Ile Ser 690 695 700Ser Gly Glu Gln Lys Trp Gly Arg Met Cys Gly Leu Val Met Leu Leu705 710 715 720Pro His Gly Tyr Glu Gly Gln Gly Pro Glu His Ser Ser Ala Arg Leu 725 730 735Glu Arg Tyr Leu Gln Leu Cys Ala Glu Gln Asn Met Gln Val Cys Val 740 745 750Pro Ser Thr Pro Ala Gln Val Tyr His Met Leu Arg Arg Gln Ala Leu 755 760 765Arg Gly Met Arg Arg Pro Leu Val Val Met Ser Pro Lys Ser Leu Leu 770 775 780Arg His Pro Leu Ala Ile Ser Ser Leu Asp Glu Leu Ala Asn Gly Ser785 790 795 800Phe Gln Pro Ala Ile Gly Glu Ile Asp Asp Leu Asp Pro Gln Gly Val 805 810 815Lys Arg Val Val Leu Cys Ser Gly Lys Val Tyr Tyr Asp Leu Leu Glu 820 825 830Gln Arg Arg Lys Asp Glu Lys Thr Asp Val Ala Ile Val Arg Ile Glu 835 840 845Gln Leu Tyr Pro Phe Pro His Gln Ala Val Gln Glu Ala Leu Lys Ala 850 855 860Tyr Ser His Val Gln Asp Phe Val Trp Cys Gln Glu Glu Pro Leu Asn865 870 875 880Gln Gly Ala Trp Tyr Cys Ser Gln His His Phe Arg Asp Val Val Pro 885 890 895Phe Gly Ala Thr Leu Arg Tyr Ala Gly Arg Pro Ala Ser Ala Ser Pro 900 905 910Ala Val Gly Tyr Met Ser Val His Gln Gln Gln Gln Gln Asp Leu Val 915 920 925Asn Asp Ala Leu Asn Val Asn 930 9354407PRTEnterobacter agglomerans 4Met Ser Ser Val Asp Ile Leu Val Pro Asp Leu Pro Glu Ser Val Ala1 5 10 15Asp Ala Thr Val Ala Thr Trp His Lys Lys Pro Gly Asp Ala Val Ser 20 25 30Arg Asp Glu Val Ile Val Glu Ile Glu Thr Asp Lys Val Val Leu Glu 35 40 45Val Pro Ala Ser Ala Asp Gly Val Leu Glu Ala Val Leu Glu Asp Glu 50 55 60Gly Ala Thr Val Thr Ser Arg Gln Ile Leu Gly Arg Leu Lys Glu Gly65 70 75 80Asn Ser Ala Gly Lys Glu Ser Ser Ala Lys Ala Glu Ser Asn Asp Thr 85 90 95Thr Pro Ala Gln Arg Gln Thr Ala Ser Leu Glu Glu Glu Ser Ser Asp 100 105 110Ala Leu Ser Pro Ala Ile Arg Arg Leu Ile Ala Glu His Asn Leu Asp 115 120 125Ala Ala Gln Ile Lys Gly Thr Gly Val Gly Gly Arg Leu Thr Arg Glu 130 135 140Asp Val Glu Lys His Leu Ala Asn Lys Pro Gln Ala Glu Lys Ala Ala145 150 155 160Ala Pro Ala Ala Gly Ala Ala Thr Ala Gln Gln Pro Val Ala Asn Arg 165 170 175Ser Glu Lys Arg Val Pro Met Thr Arg Leu Arg Lys Arg Val Ala Glu 180 185 190Arg Leu Leu Glu Ala Lys Asn Ser Thr Ala Met Leu Thr Thr Phe Asn 195 200 205Glu Ile Asn Met Lys Pro Ile Met Asp Leu Arg Lys Gln Tyr Gly Asp 210 215 220Ala Phe Glu Lys Arg His Gly Val Arg Leu Gly Phe Met Ser Phe Tyr225 230 235 240Ile Lys Ala Val Val Glu Ala Leu Lys Arg Tyr Pro Glu Val Asn Ala 245 250 255Ser Ile Asp Gly Glu Asp Val Val Tyr His Asn Tyr Phe Asp Val Ser 260 265 270Ile Ala Val Ser Thr Pro Arg Gly Leu Val Thr Pro Val Leu Arg Asp 275 280 285Val Asp Ala Leu Ser Met Ala Asp Ile Glu Lys Lys Ile Lys Glu Leu 290 295 300Ala Val Lys Gly Arg Asp Gly Lys Leu Thr Val Asp Asp Leu Thr Gly305 310 315 320Gly Asn Phe Thr Ile Thr Asn Gly Gly Val Phe Gly Ser Leu Met Ser 325 330 335Thr Pro Ile Ile Asn Pro Pro Gln Ser Ala Ile Leu Gly Met His Ala 340 345 350Ile Lys Asp Arg Pro Met Ala Val Asn Gly Gln Val Val Ile Leu Pro 355 360 365Met Met Tyr Leu Ala Leu Ser Tyr Asp His Arg Leu Ile Asp Gly Arg 370 375 380Glu Ser Val Gly Tyr Leu Val Ala Val Lys Glu Met Leu Glu Asp Pro385 390 395 400Ala Arg Leu Leu Leu Asp Val 405540PRTEnterobacter agglomerans 5Met Asn Leu His Glu Tyr Gln Ala Lys Gln Leu Phe Ala Arg Tyr Gly1 5 10 15Met Pro Ala Pro Thr Gly Tyr Ala Cys Thr Thr Pro Arg Glu Ala Glu 20 25 30Glu Ala Ala Ser Lys Ile Gly Ala 35 40630DNAArtificial Sequencemisc_featureArtificial Sequence synthetic DNA 6gtcgacaata gccygaatct gttctggtcg 30730DNAArtificial Sequencemisc_featureArtificial Sequence synthetic DNA 7aagcttatcg acgctcccct ccccaccgtt 308936PRTEscherichia coli 8Met Gln Asn Ser Ala Leu Lys Ala Trp Leu Asp Ser Ser Tyr Leu Ser1 5 10 15Gly Ala Asn Gln Ser Trp Glu Ile Glu Gln Leu Tyr Glu Asp Phe Leu 20 25 30Thr Asp Pro Asp Ser Val Asp Ala Asn Trp Arg Ser Thr Phe Gln Gln 35 40 45Leu Pro Gly Thr Gly Val Lys Pro Asp Gln Phe His Ser Gln Thr Arg 50 55 60Glu Tyr Phe Arg Arg Leu Ala Lys Asp Ala Ser Arg Tyr Ser Ser Thr65 70 75 80Ile Ser Asp Pro Asp Thr Asn Val Lys Gln Val Lys Val Leu Gln Leu 85 90 95Ile Asn Ala Tyr Arg Phe Arg Gly His Gln His Ala Asn Leu Asp Pro 100 105 110Leu Gly Leu Trp Gln Gln Asp Lys Val Ala Asp Leu Asp Pro Ser Phe 115 120 125His Asp Leu Thr Glu Ala Asp Phe Gln Glu Thr Phe Asn Val Gly Ser 130 135 140Phe Ala Ser Gly Lys Glu Thr Met Lys Leu Gly Glu Leu Leu Glu Ala145 150 155 160Leu Lys Gln Thr Tyr Cys Gly Pro Ile Gly Ala Glu Tyr Met His Ile 165 170 175Thr Ser Thr Glu Glu Lys Arg Trp Ile Gln Gln Arg Ile Glu Ser Gly 180 185 190Arg Ala Thr Phe Asn Ser Glu Glu Lys Lys Arg Phe Leu Ser Glu Leu 195 200 205Thr Ala Ala Glu Gly Leu Glu Arg Tyr Leu Gly Ala Lys Phe Pro Gly 210 215 220Ala Lys Arg Phe Ser Leu Glu Gly Gly Asp Ala Leu Ile Pro Met Leu225 230 235 240Lys Glu Met Ile Arg His Ala Gly Asn Ser Gly Thr Arg Glu Val Val 245 250 255Leu Gly Met Ala His Arg Gly Arg Leu Asn Val Leu Asn Val Leu Gly 260 265 270Lys Lys Pro Gln Asp Leu Phe Asp Glu Phe Ala Gly Lys His Lys Glu 275 280 285His Leu Gly Thr Gly Asp Val Lys Tyr His Met Gly Phe Ser Ser Asp 290 295 300Phe Gln Thr Asp Gly Gly Leu Val His Leu Ala Leu Ala Phe Asn Pro305 310 315 320Ser His Leu Glu Ile Val Ser Pro Val Val Ile Gly Ser Val Arg Ala 325 330 335Arg Leu Asp Arg Leu Asp Glu Pro Ser Ser Asn Lys Val Leu Pro Ile 340 345 350Thr Ile His Gly Asp Ala Ala Val Thr Gly Gln Gly Val Val Gln Glu 355 360 365Thr Leu Asn Met Ser Lys Ala Arg Gly Tyr Glu Val Gly Gly Thr Val 370 375 380Arg Ile Val Ile Asn Asn Gln Val Gly Phe Thr Thr Ser Asn Pro Leu385 390 395 400Asp Ala Arg Ser Thr Pro Tyr Cys Thr Asp Ile Gly Lys Met Val Gln 405 410 415Ala Pro Ile Phe His Val Asn Ala Asp Asp Pro Glu Ala Val Ala Phe 420 425 430Val Thr Arg Leu Ala Leu Asp Phe Arg Asn Thr Phe Lys Arg Asp Val 435 440 445Phe Ile Asp Leu Val Ser Tyr Arg Arg His Gly His Asn Asn Glu Ala 450 455 460Asp Glu Pro Ser Ala Thr Gln Pro Leu Met Tyr Gln Lys Ile Lys Lys465 470 475 480His Pro Thr Pro Arg Lys Ile Tyr Ala Asp Lys Leu Glu Gln Glu Lys 485 490 495Val Ala Thr Leu Glu Asp Ala Thr Glu Met Val Asn Leu Tyr Arg Asp 500 505 510Ala Leu Asp Ala Gly Asp Cys Val Val Ala Glu Trp Arg Pro Met Asn 515 520 525Met His Ser Phe Thr Trp Ser Pro Tyr Leu Asn His Glu Trp Asp Glu 530 535 540Glu Tyr Pro Asn Lys Val Glu Met Lys Arg Leu Gln Glu Leu Ala Lys545 550 555 560Arg Ile Ser Thr Val Pro Glu Ala Val Glu Met Gln Ser Arg Val Ala 565 570 575Lys Ile Tyr Gly Asp Arg Gln Ala Met Ala Ala Gly Glu Lys Leu Phe 580 585 590Asp Trp Gly Gly Ala Glu Asn Leu Ala Tyr Ala Thr Leu Val Asp Glu 595 600 605Gly Ile Pro Val Arg Leu Ser Gly Glu Asp Ser Gly Arg Gly Thr Phe 610 615 620Phe His Arg His Ala Val Ile His Asn Gln Ser Asn Gly Ser Thr Tyr625 630 635 640Thr Pro Leu Gln His Ile His Asn Gly Gln Gly Ala Phe Arg Val Trp 645 650 655Asp Ser Val Leu Ser Glu Glu Ala Val Leu Ala Phe Glu Tyr Gly Tyr 660 665 670Ala Thr Ala Glu Pro Arg Thr Leu Thr Ile Trp Glu Ala Gln Phe Gly 675 680 685Asp Phe Ala Asn Gly Ala Gln Val Val Ile Asp Gln Phe Ile Ser Ser 690 695 700Gly Glu Gln Lys Trp Gly Arg Met Cys Gly Leu Val Met Leu Leu Pro705 710 715 720His Gly Tyr Glu Gly Gln Gly Pro Glu His Ser Ser Ala Arg Leu Glu 725 730 735Arg Tyr Leu Gln Leu Cys Ala Glu Gln Asn Asn Gln Val Cys Val Pro 740 745 750Ser Thr Pro Ala Gln Val Tyr His Met Leu Arg Arg Gln Ala Leu Arg 755 760 765Gly Met Arg Arg Pro Leu Val Val Met Ser Pro Lys Ser Leu Leu Arg 770 775 780His Pro Leu Ala Val Ser Ser Leu Glu Glu Leu Ala Asn Gly Thr Phe785 790 795 800Leu Pro Ala Ile Gly Glu Glu Ile Asp Glu Leu Asp Pro Lys Gly Val 805 810 815Lys Arg Val Val Met Cys Ser Ser Gly Lys Val Tyr Tyr Asp Leu Leu 820 825 830Glu Gln Arg Arg Lys Asn Asn Gln His Asp Val Ala Ile Val Arg Ile 835 840 845Glu Gln Leu Tyr Pro Phe Pro His Lys Ala Met Gln Glu Val Leu Gln 850 855 860Gln Phe Ala His Val Lys Asp Phe Val Trp Cys Gln Glu Glu Pro Leu865 870 875 880Asn Gln Gly Ala Trp Tyr Cys Ser Gln His His Phe Arg Glu Val Ile 885 890 895Pro Phe Gly Ala Ser Leu Arg Tyr Ala Gly Arg Pro Ala Ser Ala Ser 900 905 910Pro Ala Val Gly Tyr Met Ser Val His Gln Lys Gln Gln Gln Asp Leu 915 920 925Val Asn Asp Ala Leu Asn Val Glu 930 9359405PRTEscherichia coli 9Met Ser Ser Val Asp Ile Leu Val Pro Asp Leu Pro Glu Ser Val Ala1 5 10 15Asp Ala Thr Val Ala Thr Trp His Lys Lys Pro Gly Asp Ala Val Val 20 25 30Arg Asp Glu Val Leu Val Glu Ile Glu Thr Asp Lys Val Val Leu Glu 35 40 45Val Pro Ala Ser Ala Asp Gly Ile Leu Asp Ala Val Leu Glu Asp Glu 50 55 60Gly Thr Thr Val Thr Ser Arg Gln Ile Leu Gly Arg Leu Arg Glu Gly65 70 75 80Asn Ser Ala Gly Lys Glu Thr Ser Ala Lys Ser Glu Glu Lys Ala Ser 85

90 95Thr Pro Ala Gln Arg Gln Gln Ala Ser Leu Glu Glu Gln Asn Asn Asp 100 105 110Ala Leu Ser Pro Ala Ile Arg Arg Leu Leu Ala Glu His Asn Leu Asp 115 120 125Ala Ser Ala Ile Lys Gly Thr Gly Val Gly Gly Arg Leu Thr Arg Glu 130 135 140Asp Val Glu Lys His Leu Ala Lys Ala Pro Ala Lys Glu Ser Ala Pro145 150 155 160Ala Ala Ala Ala Pro Ala Ala Gln Pro Ala Leu Ala Ala Arg Ser Glu 165 170 175Lys Arg Val Pro Met Thr Arg Leu Arg Lys Arg Val Ala Glu Arg Leu 180 185 190Leu Glu Ala Lys Asn Ser Thr Ala Met Leu Thr Thr Phe Asn Glu Val 195 200 205Asn Met Lys Pro Ile Met Asp Leu Arg Lys Gln Tyr Gly Glu Ala Phe 210 215 220Glu Lys Arg His Gly Ile Arg Leu Gly Phe Met Ser Phe Tyr Val Lys225 230 235 240Ala Val Val Glu Ala Leu Lys Arg Tyr Pro Glu Val Asn Ala Ser Ile 245 250 255Asp Gly Asp Asp Val Val Tyr His Asn Tyr Phe Asp Val Ser Met Ala 260 265 270Val Ser Thr Pro Arg Gly Leu Val Thr Pro Val Leu Arg Asp Val Asp 275 280 285Thr Leu Gly Met Ala Asp Ile Glu Lys Lys Ile Lys Glu Leu Ala Val 290 295 300Lys Gly Arg Asp Gly Lys Leu Thr Val Glu Asp Leu Thr Gly Gly Asn305 310 315 320Phe Thr Ile Thr Asn Gly Gly Val Phe Gly Ser Leu Met Ser Thr Pro 325 330 335Ile Ile Asn Pro Pro Gln Ser Ala Ile Leu Gly Met His Ala Ile Lys 340 345 350Asp Arg Pro Met Ala Val Asn Gly Gln Val Glu Ile Leu Pro Met Met 355 360 365Tyr Leu Ala Leu Ser Tyr Asp His Arg Leu Ile Asp Gly Arg Glu Ser 370 375 380Val Gly Phe Leu Val Thr Ile Lys Glu Leu Leu Glu Asp Pro Thr Arg385 390 395 400Leu Leu Leu Asp Val 4051041PRTEnterobacter agglomerans 10Met Asn Leu His Glu Tyr Gln Ala Lys Gln Leu Phe Ala Arg Tyr Gly1 5 10 15Met Pro Ala Pro Thr Gly Tyr Ala Cys Thr Thr Pro Arg Glu Ala Glu 20 25 30Glu Ala Ala Ser Lys Ile Gly Ala Gly 35 401160PRTEscherichia coli 11Met Asn Leu His Glu Tyr Gln Ala Lys Gln Leu Phe Ala Arg Tyr Gly1 5 10 15Leu Pro Ala Pro Val Gly Tyr Ala Cys Thr Thr Pro Arg Glu Ala Glu 20 25 30Glu Ala Ala Ser Lys Ile Gly Ala Gly Pro Trp Val Val Lys Cys Gln 35 40 45Val His Ala Gly Gly Arg Gly Lys Ala Gly Gly Val 50 55 601258PRTEscherichia coli 12Phe Leu Ile Asp Ser Arg Asp Thr Glu Thr Asp Ser Arg Leu Asp Gly1 5 10 15Leu Ser Asp Ala Phe Ser Val Phe Arg Cys His Ser Ile Met Asn Cys 20 25 30Val Ser Val Cys Pro Lys Gly Leu Asn Pro Thr Arg Ala Ile Gly His 35 40 45Ile Lys Ser Met Leu Leu Gln Arg Asn Ala 50 55

Claims

What is claimed is:

1. A method for producing L-glutamic acid by fermentation, which comprises culturing an isolated microorganism in a liquid medium of which pH is adjusted to the pH at which L-glutamic acid is precipitated, to produce and accumulate L-glutamic acid and precipitate L-glutamic acid in the medium, wherein said microorganism can metabolize a carbon source at a specific pH in a liquid medium containing the carbon source and L-glutamic acid at a saturation concentration, and has the ability to accumulate L-glutamic acid in an amount exceeding the amount corresponding to the saturation concentration in the liquid medium at the pH, wherein said microorganism is .[.Enterobacter agglomerans.]. .Iadd.Pantoea ananatis.Iaddend., and wherein said microorganism has at least one of the following characteristics: (a) the microorganism has increased activity, as compared to a corresponding wild-type microorganism, of an enzyme that catalyzes a reaction for biosynthesis of L-glutamic acid; and (b) the microorganism has decreased activity, as compared to a corresponding wild-type microorganism, or deficient activity of an enzyme that catalyzes a reaction of a pathway branching from a biosynthetic pathway of L-glutamic acid and producing a compound other than L-glutamic acid.

2. The method according to claim 1, wherein said microorganism can grow in the liquid medium.

3. The method according to claim 1, wherein the pH is not more than 5.0.

4. The method according to claim 1, wherein in said microorganism an activity of at least one enzyme selected from the group consisting of citrate synthase, phosphoenolpyruvate carboxylase and glutamate dehydrogenase, is increased.

5. The method according to claim 1, wherein in said microorganism the enzyme that catalyzes the reaction of the pathway branching from the biosynthetic pathway of L-glutamic acid and producing the compound other than L-glutamic acid is .alpha.-ketoglutarate dehydrogenase.

6. The method according to claim 1, wherein said microorganism has a mutation that causes less extracellular secretion of a viscous material compared with a wild strain when cultured in a medium containing a saccharide.

.Iadd.7. The method according to claim 1, wherein said microorganism is Pantoea ananatis AJ13355 strain..Iaddend.