U.S. patent application number 10/508184 was filed with the patent office on 2006-03-16 for novel catalytic activities of oxidoreductases for oxidation and or bleaching.
Invention is credited to Hans-Peter Call.
Application Number | 20060054290 10/508184 |
Document ID | / |
Family ID | 7713188 |
Filed Date | 2006-03-16 |
United States Patent
Application |
20060054290 |
Kind Code |
A1 |
Call; Hans-Peter |
March 16, 2006 |
Novel catalytic activities of oxidoreductases for oxidation and or
bleaching
Abstract
A new enzyme-based process for oxidation and/or bleaching is
described, comprising of oxidoreductases such as laccases and/or
peroxidases--seperately or in combination--in the presence of their
respective co-substrates like O.sub.2, air, H.sub.2O.sub.2, organic
peroxides, peracids etc. and comprising of enhancer compounds from
the class of oxocarbons, from the class of urazoles and hydrazides,
from the class of hydantoins and the class of nitril
(Cyan)-compounds, and comprising additionally of carbonyl compounds
such as ketones, aldehyds, whereby the combination of enzyme,
co-substrate, enhancer compound and carbonyl compound generate
active oxygen species like dioxiranes, dioxetanes, peroxy-compounds
etc. or form other reactive compounds or transition states like
radicals (kation radicals, anion radicals) or reactive
(red/ox-active) neutral compounds as oxidizing and/or bleaching
agents.
Inventors: |
Call; Hans-Peter;
(Ubach-Palenberg, DE) |
Correspondence
Address: |
Dr Hans-Peter Call
Heinsberger Strasse 14 a
Ubach-Palenberg
52531
DE
|
Family ID: |
7713188 |
Appl. No.: |
10/508184 |
Filed: |
January 26, 2003 |
PCT Filed: |
January 26, 2003 |
PCT NO: |
PCT/DE03/00201 |
371 Date: |
August 11, 2005 |
Current U.S.
Class: |
162/1 |
Current CPC
Class: |
D21C 9/1036 20130101;
D21C 5/005 20130101; C11D 3/38654 20130101; C11D 7/264
20130101 |
Class at
Publication: |
162/001 |
International
Class: |
D21C 9/08 20060101
D21C009/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 26, 2002 |
DE |
102 03 135.5 |
Claims
1) New enzyme-based process for oxidation and/or bleaching
comprising of oxidoreductases such as laccases and/or
peroxidases--seperately or in combination--in the presence of their
respective co-substrates like O.sub.2, air, H.sub.2O.sub.2, organic
peroxides, peracids etc. and comprising of enhancer compounds from
the class of oxocarbons, from the class of urazoles and hydrazides,
from the class of hydantoins and the class of nitril
(Cyan)-compounds, and comprising additionally of carbonyl compounds
such as ketones, aldehyds, whereby the combination of enzyme,
co-substrate, enhancer compound and carbonyl compound generate
active oxygen species like dioxiranes, dioxetanes, peroxy-compounds
etc. or form other reactive compounds or transition states like
radicals (kation radicals, anion radicals) or reactive
(red/ox-active) neutral compounds as oxidizing and/or bleaching
agents.
2) New enzyme-based process for oxidation and/or bleaching
according to claim 1 comprising that the enhancer compounds belong
to the group of oxocarbons like .alpha.-hydroxy-carbonyl compounds,
.alpha.-dicarbonyl compounds, .beta.-hydroxycarbonyl compounds and
.beta.-dicarbonyl compounds, linear compounds with double bonds
(enols) and compounds from the group of cyclic oxocarbons like
deltic acid, squaric acid, crocoic acid, rhodizonic acid,
tetrahydroxy-p-hydroquinone and their salts and derivatives.
3) New enzyme-based process for oxidation and/or bleaching
according to claim 1 comprising that that the enhancer compounds
belong to the group of amides such as hydrazides, cyclic
hydrazides, urazoles and phthalhydrazides.
4) New enzyme-based process for oxidation and/or bleaching
according to claim 1 comprising that that the enhancer compounds
belong to the group of imides like hydantoins, cyclic imides and
hydantoin derivatives.
5) New enzyme-based process for oxidation and/or bleaching
according to claim 1
5) New enzyme-based process for oxidation and/or bleaching
according to claim 1 comprising that that the enhancer compounds
belong to the group of nitril-(Cyan) compounds such as cyanamide or
dicyandiamide.
6) New enzyme-based process for oxidation and/or bleaching
according to claim 1 comprising that additionally carbonyl
compounds--mainly non-cyclic substances--are added.
7) New enzyme-based process for oxidation and/or bleaching
according to claim 1 comprising that as enzymes oxidoreductases of
the classes 1.1.1. bis 1.97 are used.
8) New enzyme-based process for oxidation and/or bleaching
according to claim 1 comprising that as oxidoreductases laccases
and peroxidases are used.
9) New enzyme-based process for oxidation and/or bleaching
according to claim 1 comprising that as additional enzyme-based
systems HOS (hydrolase mediated oxidation system), peroxynitreous
acid generating system, ferrocene/peroxide system, organosulfonic
acid/peroxide/ketone system, activated sulfite/superoxide/ketone
system and other state-of-the-art oxidoreductase mediator systems
are added either simultaneously or successively in any order are
added.
10) New enzyme-based process for oxidation and/or bleaching
according to claim 1 comprising that as co-substrates preferrably
air, oxygen, ozone, peroxides, such as H.sub.2O.sub.2, organic
peroxides, peracids such as peracetic, performic, persulfuric,
pernitric, metachloroperoxybenzoic and perchloric acid, per
compounds such as perborates, percarbonates or persulfates, or
oxygen species and the radicals thereof such as the OH, OOH.sup.-
and OH.sup.+ radical, superoxide (O.sub.2--), dioxygenyl cation
(O.sub.2.sup.+), singlet oxygen are used.
11) Use of the enzymatic oxidation and/or bleaching system
according to claim 1 to 10 in a process for the delignification
and/or modificaton and/or bleaching of pulps from wood and annual
plants and high yield pulps and deinked pulps, whereby the
reactions of the oxidation and/or bleaching systems are performed
in a pH-range of pH 3 to 11, preferably pH 3 to 9, at a temperature
of 20 to 95.degree. C., preferably of 40 to 95.degree. C., at a
consistency of 0.5 to 40%, preferably of 4 to 15%, in the presence
of oxygen or air at atmospheric pressure to a slight overpressure
(up to 2 bar). The laccase concentrations or peroxidase
concentrations lay in the range of 2-500 g pure enzyme per ton
pulp, the concentrations of the enhancer compounds lay in the range
of 1-15 kg per ton pulp, the H.sub.2O.sub.2 concentrations in the
range of 0.2 to 15 kg per ton pulp and the concentrations of
carbonyl compounds in the range of 0.2 to 5 kg per ton pulp.
12) Use of the enzymatic oxidation and/or bleaching system
according to claim 1 to 11 in a process for the delignification and
/or modificaton and/or bleaching of pulps from wood and annual
plants and high yield pulps and deinked pulps whereby an acid wash
or a Q-step is used before and/or after the reaction of the enzyme
component system and the acid wash is carried out at 60-120.degree.
C., at pH 2 to 5.5, for 30-90 min and at 4-20% pulp consistency,
and the Q-step is carried out with 0.05-1%, preferably with 0.2 to
0.5% of chelator at 60-100.degree. C., at pH 2 to 5.5 for 30-90 min
and a consistency of 4-20%.
13) Use of the enzymatic oxidation and/or bleaching system
according to claim 1 to 12 in a process for the delignification and
/or modificaton and/or bleaching of pulps from wood and annual
plants and high yield pulps and deinked pulps, whereby the acid
wash and the Q-step are carried out for 1 hour at 60-90.degree. C.,
at pH 2 to 5 and at 10% pulp consistency.
14 Use of the enzymatic oxidation and/or bleaching system according
to claim 1 to 13 in a process for the delignification and/or
modificaton and/or bleaching of pulps from wood and annual plants
and high yield pulps and recycling pulps whereby it can be applied
once or several times, either before and/or after the washing and
extraction of the treated material with NaOH etc., or without these
intermediate steps, but also before and/or after pretreatment or
post-treatment steps, such as acid washing, Q-steps, alkaline
leaching or bleaching steps such as peroxide bleaching,
O.sub.2-enhanced peroxide steps, pressurized peroxide steps,
O.sub.2-delignification, Cl.sub.2-bleaching, CIO.sub.2-bleaching,
Cl.sub.2/CIO.sub.2-bleaching, peracid bleaching, peracid-enhanced
O.sub.2/peroxide bleaching, ozone bleaching, dioxirane bleaching,
reductive bleaching steps, other treatments such as swelling steps,
sulfonations, NO/NO.sub.2 treatments, nitrosylsulfuric acid
treatment, enzyme treatments, for example treatments with
hydrolases, such as cellulases and/or hemicellulases (for example,
xylanase, mannase etc) and/or amylases and/or pectinases and/or
proteinases and/or lipases and/or amidases and/or oxidoreductases
such as, for example, laccases and/or peroxidases etc., or several
combined treatments.
15) Use of the enzymatic oxidation and/or bleaching system
according to claim 1 to 14 in a process for the delignification and
/or modificaton and/or bleaching of pulps from wood and annual
plants and high yield pulps and deinked pulps, said process being
carried out in several steps and whereby between each step is
applied a washing or washing and extraction step with alkaline
hydroxide solution, or neither washing nor extraction takes
place.
16) Use of the enzymatic oxidation and/or bleaching system
according to claim 1 bis 15 in the bleaching of cellulose/wood
pulp, in the treatment of different wastewaters, in the preparation
of lignin solutions or gels of the corresponding binders/adhesives
and of wood-based composites, as enzymatic deinking system, as
oxidation systems in organic synthesis, as bleaching agent in
detergents, as bleaching and/or oxidation systems in textile
industry, in coal liquefaction.
Description
[0001] It is wellknown, that enzymes like e.g. peroxidases,
especially horseradish peroxidase (HRP), lignin peroxidases and
manganese peroxidases and also special oxidases such as laccases,
which all belong to the lignolytic enzymes, can oxidize a huge
variety of different substrates either in the presence of
H.sub.2O.sub.2, organic peroxides or peracids (peroxidases) or in
the presence of air or O.sub.2 (oxidases/laccases).
[0002] During the last years several applications of the mentioned
enzymes were published or patented like e.g. their use as mild
oxidants in the chemical synthesis or in food field, as
decolorizing oxidants of dyes e.g. in waste waters, as
labeling-enzymes for special analysis approaches and in biosensors
etc.
[0003] Furthermore some applications were published and patented
referring to enzymes which work together with special mediator
compounds (WO96/18770/, WO 94/29510, WO 94/12619, WO 94/12620 und
WO 94/12621).
[0004] In these cases the preferred enzyme is mostly laccase, an
enzyme which is today commercial available.
[0005] On the one hand these mediator compounds make possible an
oxidation of substrates with higher oxidation potential, they
normally cannot be oxidized by laccases alone; and on the other
hand they cause that the so-called laccase mediator system--due to
the fact that the mediator compounds are free-diffusible and
low-molecular--can also degradate substrates in not freely
accessable substances such as e.g. lignin in pulp fibres. Free
enzymes wouldn't cause any significant substrate degradation due to
their--besides the low oxidation power--too large molecule
size.
[0006] Besides these laccase-based enzymatic approaches only the
manganes peroxidase systems (MnP-systems) which can be found in
withe-rotting fungi and work with the aid of chelated Mn.sup.2+ as
natural mediator can be applied as an in-vivo-system for lignin
degradation in pulps. The main drawbacks regarding the performance
of these systems are on the one hand their strong sensitivity
against H.sub.2O.sub.2 as co-oxidant and on the other hand the
difficulties in production of the enzymes. These difficulties have
made a use in a larger scale and therefore a commercialization
impossible.
[0007] Due to the too large molecular weight which makes a
penetration into the fibres impossible (see above) und due to the
fact that there are so far no specific mediator compounds have Due
to the too large molecular weight which makes a penetration into
the fibres impossible (see above) und due to the fact that there
are so far no specific mediator compounds have been found, the use
of lignin peroxidase causes no delignification but a lignin
polymerisation.
[0008] Despite the good performance of laccase- mediator-systems
(LMS) and the very good selectivity i.e. good pulp properties which
can be obtained, a) the high price mainly of the mediator compounds
b) their necessary relatively high dosages (the reactions are
stochiometric and not catalytic) and c) the oftenly existing
environmental risks due to the possible toxicity of the mediator
compounds prevent the broad implementation of these systems.
[0009] On the other side there is a great demand for alternative
bleaching systems mainly due to the necessity for closed mill loops
which can only difficult be obtained (because of e.g. of the
corrosion problems) with the aid of ECF-bleaching (elemental
chlorine free bleaching) with chlorine dioxide as main bleaching
agent.
[0010] Therefore it is the target of the present invention to
provide an oxidation-/bleaching system which hasn't the
disadvantages of the mentioned state-of-the-art systems.
[0011] This can be solved by providing a new process for oxidation
and/or bleaching comprising of
ACCORDING TO THE INVENTION
[0012] oxidoreductases such as laccases and/or
peroxidases--seperately or in combination--in the presence of their
respective co-substrates like O.sub.2, air, H.sub.2O.sub.2, organic
peroxides, peracids etc. and comprising of
[0013] enhancer compounds from the class of oxocarbons, from the
class of urazoles and hydrazides, from the class of hydantoins and
the class of nitril (Cyan)-compounds, and comprising additionally
of
[0014] carbonyl compounds such as ketones, aldehyds,
[0015] whereby the combination of enzyme, co-substrate, enhancer
compound and carbonyl compound generate active oxygen species like
dioxiranes, dioxetanes, peroxy-compounds etc. or form (according
e.g. to the literature: K. Deuchert et. al., Angewandte Chemie 90,
S. 927-938, 1978) also other reactive compounds or transition
states like radicals (kation radicals, anion radicals) or reactive
(red/ox-active) neutreal compounds as oxidizing and/or bleaching
agents.
[0016] As oxocarbon compounds such compounds are preferably used as
cited in the literature: Chemie in unserer Zeit, 16. Jahrgang 1982,
Nr. 2, S. 57-67 inclusivly of the therein quoted literature
preferably: R.West et al., Oxocarbons and their Reactions, in J.
Zabicky ed., "The chemistry of the Carbonyl Group", Wyley
(Interscience), 1970; R.West, Oxocarbons,
[0017] Academic
[0018] Press, 1980 und Rompp Chemie Lexikon, Thieme Verlag, 1995,
S. 3175-3177.
[0019] Particularly preferred are carbonyl compounds of the general
formula I, such as .alpha.-hydroxycarbonyl compounds of general
formula Ia, .alpha.-dicarbonyl compounds of general formula lb,
.beta.-hydroxycarbonyl compounds of general formula Ic and
.beta.-dicarbonyl compounds of general formula Id: ##STR1## wherein
R.sup.1 to R.sup.8 independently of one another are selected from
the group consisting of hydrogen, a halogen, an alkyl group, an
alkyloxy group, an aryl group, an aryloxy group, a hydroxy group,
an oxo group, a formyl group, a thioxo group, a mercapto group, an
alkylthio group, a sulfeno group, a sulfino group, a sulfo group, a
sulfamoyl group, an amino group, an imino group, an amido group, an
amidino group, a hydroxycarbamoyl group, a hydroximino group, a
nitroso group, a nitro group and a hydrazono group, with R.sup.1
and R.sup.2; R.sup.3 and R.sup.4; R.sup.5 and R.sup.6; and R.sup.7
and R.sup.8 possibly being linked together to form a single group,
and wherein n is greater than or equal to 1;
[0020] particularly preferred are such compounds of general formula
II (linear compounds with double bonds/enols): ##STR2## wherein
R.sup.9 and R.sup.10, independently of one another, are selected
from the group consisting of hydrogen, a halogen, an alkyl group,
an alkyloxy group, an aryl group, an aryloxy group, a hydroxy
group, an oxo group, a formyl group, a thioxo group, a mercapto
group, an alkylthio group, a sulfeno group, a sulfino group, a
sulfo group, a sulfamoyl group, an amino group, an imino group, an
amido group, an amidino group, a hydroxycarbamoyl group, a
hydroximino group, a nitroso group, a nitro group and a hydrazono
group, and R.sup.9 and R.sup.10 are possibly linked together to
form a single group;
[0021] Furthermore preferred are such compounds of general
structure III (cyclic compounds, groups not OH, derivatives of
squaric acid, OH group derivatized): ##STR3## wherein R.sup.11 and
R.sup.12, independently of one another are selected from the group
consisting of hydrogen, a halogen, an alkyl group, an alkyloxy
group, an aryl group, an aryloxy group, a hydroxy group, an oxo
group, a formyl group, a thioxo group, a mercapto group, an
alkylthio group, a sulfeno group, a sulfino group, a sulfo group, a
sulfamoyl group, an amino group, an imino group, an amido group, an
amidino group, a hydroxycarbamoyl group, a hydroximino group, a
nitroso group, a nitro group and a hydrazono group, and m is
greater than or equal to 0. Particularly preferred are cyclic
oxocarbon compounds of the general formula IV (general sum formula:
C.sub.xO.sub.x wherin x=>3.
[0022] Struktur element: ##STR4##
[0023] p.gtoreq.0.
[0024] Particularly preferred are compounds such as, for example:
deltic acid, squaric acid, croconic acid and rhodizonic acid.
##STR5##
[0025] Particularly preferred are also tetrahydroxy-p-benzoquinones
their saltse and derivatives and the corresponding salts and
derivatives of the deltic acid, squaric acid, croconic acid and
rhodizonic acid
[0026] Also particularly prteferred are derivatives of squaric acid
according to the literature: K. Deuchert et. al., Angewandte
Chemie, 90, 1978, S. 927-938.
[0027] Particularly preferred compounds from the group of amides
are hydrazides and urozoles of the general formula V (amides) and
VI (hydrazides): ##STR6## wherein X is C.dbd.O or O.dbd.S.dbd.O; R
is the same or different and independently of one another is
hydrogen, an alkyl group, an aryl group or an acyl group; wherein X
is C.dbd.O or O.dbd.S.dbd.O; R is the same or different and
independently of one another is hydrogen, and alkyl group, an aryl
group or an acyl group;
[0028] Most particularly preferred are compounds like carbazates
such as methyl-, ethyl-, tert, butyl-, benzylcarbazate etc. and
pyrazoles and respective derivatives.
[0029] Particularly preferred are cyclic hydrazides of the general
formula VII ##STR7## wherein X is C.dbd.O or O.dbd.S.dbd.O (cyclic
hydrazides of dicarbonic acids or disulfonic acids).
[0030] R is the same or different and independently of one another
is hydrogen, an alkyl group, an aryl group or an acyl group.
[0031] G is selected from the group consisting of CH.sub.2,
CH.sub.2--CH.sub.2, CHR.sup.1--CHR.sup.1, CH.dbd.CH,
CR.sub.2--CR.sub.2, NH, NR.sup.3, C.dbd.O, ortho-C.sub.6H.sub.4,
ortho-C.sub.10H.sub.6, wherein R.sup.1 to R.sup.3 are the same or
different and independently of one another are hydrogen, an alkyl
group, an aryl group, or an acyl group;
[0032] Furthermore preferred are urazoles (formula VIII) und
phthalhydrazides (Formula IX) ##STR8## wherein R.sup.4 is hydrogen,
an alkyl group, an alkoxy group, a carboxyl group, a nitro group or
an amino group;
[0033] R is the same or different and independently of one another
is hydrogen, an alkyl group or an aryl group.
[0034] Particularly preferred are compounds such as: maleic
hydrazide, 2-nitrobenzhydrazide, p-toluenesulfonyl hydrazide,
nicotinic hydrazide, isonicotinic hydrazide,
4,4'-oxydibenzenesulfonyl hydrazide, benzoichydrazide, phthalic
hydrazide, 3-aminophthalic hydrazide, 1-naphthoic hydrazide,
3-hydroxy-2-naphthoic hydrazide, hydroxybenzhydrazide, oxamic
hydrazide, oxalic dihydrazide, terephthalic dihydrazide,
isophthalic dihydrazide, L-tyrosine hydrazide, oxalic
bis-(benzylidene hydrazide), salicylidenesalicylic hydrazide,
thiophene 2-carbonic acid hydrazide, furan 2-carbonic acid
hydrazide.
[0035] Furthermore particularly preferred are
5-arnino-S-hydroxypyrazole, 2,3-dihydrophthalazine-1,4-dione,
7-nitroindazole, 1,2-dihydropyrazine-3,6-dione.
[0036] Also particularly preferred are 4-phenylurazole,
1-phenylurazole, 4-methylurazole, 4-tert, -butyluralzole and
urazole.
[0037] From the group of imides as e.g. hydantoins, particularly
compounds of the general formula X (imides) are used: ##STR9##
wherein the R is the same or different and independently of one
another is hydrogen, an alkyl group, an aryl group, an acyl group
or an amino group.
[0038] Also particularly preferred are imides of thegeneral formula
XI: ##STR10## wherein the R is the same or different and
independently of one another is hydrogen, an alkyl group, an aryl
group, an acyl group or an amino group.
[0039] Particularly preferred are cyclische Imide of the general
formula XII: ##STR11## R is the same or different and independently
of one another is hydrogen, an alkyl group, an aryl group, an acyl
group or an amino group; G is selected from the group consisting of
CH.sub.2, CHR.sup.1, CR.sup.1R.sup.2, CH.dbd.CH,
CR.sup.3.dbd.CR.sup.4, NH, NR.sup.5, C.dbd.O, and O, wherein
R.sup.1 to R.sup.5 are the same or different and independently of
one another are hydrogen, an alkyl group, an aryl group, an alkoxy
group, or a carboxy group.
[0040] Furthrermore particularly preferred are derivatives of
hydantoins (formula XIII), like compounds, wherein the hydantoin
derivative is selected from the group consisting of
diethyl-5-hydantoyl phosphonate, 5-methyl-5-phenylhydantoin,
hydantoyl-5-acetic acid and 1,3-dibromo-5,5-dimethylhydantoin.
##STR12##
[0041] As nitrile compounds such compounds according to the
literature: Rompp Chemie
[0042] Lexikon, Thieme Verlag, 1995, S. 3012-3013 and the herein
cited literature e.g.: Chem. Unserer Zeit, 18, 1984,S.1-16 are
used.
[0043] Particularly preferred are cyanamide and dicyandiamide.
[0044] Enzymes
[0045] Oxidoreductases are preferrably used as enzymes.
Particularly preferred enzymes are laccases and peroxidases or
genereally oxidoreductases of the classes 1.1.1. to 1.97 according
to the International Enzyme Nomenclature: Committee of the
International Union of Biochemistry and Molecular Biology (Enzyme
Nomenclature, Academic Press, Inc., 1992, pp. 24-154) among which
the following are particularly preferred:
[0046] enzymes of the class 1.1, particularly preferred of the
class 1.1.5 with quinons as electron acceptor or 1.1.3 with oxygen
as acceptor particularly preferred:
[0047] cellobiose: quinone-l-oxidoreductase 1.1.5.1.
[0048] Furthermore usable are enzymes of the class 1.2,
particularly preferred 1.2.3 with oxygen as acceptor or 1.3,
particularly preferred 1.3.3 with oxygen as acceptor and 1.3.5 with
quinone as acceptor, particularly preferred: bilirubin oxidase
1.3.3.5,
[0049] Furthermore usable are enzymes of the class 1.9 particularly
preferred: cytochrome-oxidase 1.9.3.
[0050] Furthermore preferred are enzymes of the class 1.1.2 and
oxygenases, lipoxygenases 1.13, 1.14 and 1.1.5, which use superoxid
as electron acceptor, particularly preferred:
[0051] superoxide dismutase 1.15.11 and 1.16 particularly
preferred: ferrioxidase e.g. ceruloplasmin 1.16.3.1.
[0052] Especially preferred being the enzymes of sub-class 1.10.
such as catechol oxidase (tyrosinase) (1.10.3.1), L-ascorbate
oxidase (1.10.3.3), O-aminophenol oxidase (1.10.3.4) and laccase
(benzenediol: oxygen oxidoreductase) (1.10.3.2).
[0053] Other particularly preferred enzymes are those of group
1.11.
[0054] Especially preferred here are cytochrome C peroxidases
(1.11.1.5), catalase (1.11.1.6), peroxidase (1.11.1.7), iodide
peroxidase, (1.11.1.8), glutathione peroxidase (1.11.1.9), chloride
peroxidase (1.11.1.10), L-ascorbate peroxidase (1.11.1.11),
phospholipid hydroperoxide glutathione peroxidase (1.11.1.12),
manganese peroxidase (1.11.1.13) and diarylpropane peroxidase
(ligninase, lignin peroxidase) (1.11.1.14).
[0055] According to the invention the term enzyme comprises also
enzymatic active proteins or peptides or prosthetic groups of
enzymes. The enzymes used can stem from wild type microorganism
strains or genetically manipulated strains.
[0056] The mentioned enzymes are commercial available or can be
produced according to state-of-the-art production processes.
[0057] As production organisms for producing these enzymes plants,
bacteria and fingi, parts of unicellular or multi-cellular
organisms or or cell cultures can be used.
[0058] Particularly prefrred production organisms manly for the
production of lignolytic enzymes such as laccases, lignin
peroxidases and manganese peroxidases etc. are, for example, white
rotting fungi like e.g. Pleurotus, Phlebia, Trametes, Agaricus,
Lentinus, Botrytis, Cryphonectria, Hypholoma, Heterobasidion,
Phanerochaete.
[0059] As co-substrates air, oxygen, ozone, peroxides, such as
H.sub.2O.sub.2, organic peroxides, peracids such as peracetic,
performic, persulfuric, pernitric, metachloroperoxybenzoic and
perchloric acid, per compounds such as perborates, percarbonates or
persulfates, or oxygen species and the radicals thereof such as the
OH, OOH.sup.- and OH.sup.+ radical, superoxide (O.sub.2--),
dioxygenyl cation (O.sub.2.sup.+), singlet oxygen can be used.
[0060] As carbonyl compounds (ketones, aldehydes)--with exeption of
benzophenones and benziles--are particularly preferred compounds of
the general formula XIV: ##STR13##
[0061] The R.sup.1 and R.sup.2 groups can be equal or different and
denote aliphatic or aromatic groups. Moreover, the R.sup.1 and
R.sup.2 groups can form a ring containing besides carbon also
heteroatoms such as nitrogen, oxygen and sulfur.
[0062] Particularly preferred are 1,2-diketones (formula XV),
1,3-diketones (formula XVI), polyketones (polyketides) and the
tautomeric enols (formula XVII): ##STR14## wherein the R.sup.3 to
R.sup.6 groups, once again, can be equal or different and denote
aliphatic or aromatic groups. Moreover, groups R.sup.3 and R.sup.4
and groups R.sup.5 and R.sup.6, together, can form a ring
containing besides carbon also heteroatoms such as nitrogen, oxygen
or sulfur. The possibility of tautomerization or formation of a
resonance hybrid is particularly important in this case. Besides
general carbonyl compounds, particularly preferred are ketones,
such as, in general hydroxyketones, .alpha.,.beta.-unsaturated
ketones, oxycarboxylic acids, quinones and halogenated ketones.
[0063] Particularly preferred among these are the following:
[0064] Acetone, methyl ethyl ketone, diethyl ketone, methyl n-butyl
ketone, methyl isobutyl ketone, cyclohexanone, cyclopentanone,
2-methylcyclohexanone, 3-methylcyclohexanone,
4-methylcyclohexanone, dihydroxyacetone, diacetyl monohydrazone,
diacetyl dihydrazone, acetophenone, p-hydroxyacetophenone,
1-phenyl-3-butanone, 3-pentanone, 4-heptanone, 2-nonanone,
cycloheptanone, cyclooctanone, cyclodecanone, cyclododecanone,
dimethyl ketone, ethyl propyl ketone, methyl amyl ketone,
acetylacetone, pinacoline, methyl isopropyl ketone, methyl isoamyl
ketone, ethyl amyl ketone diisopropyl ketone, diisobutyl ketone,
methyl vinyl ketone, methyl isopropenyl ketone, mesityl oxide,
isophorone, hydroxyacetone, methoxyacetone, 2,3-pentanedione,
2,3-hexanedione, phenylacetone, propiophenone, benzophenone,
benzoin, benzil, 4,4'-dimethoxybenzil, 4'-methoxyacetophenone, 3'-
methoxyacetophenone, O-ethylbenzoine, (2-methoxyphenyl)acetone,
(4-methoxyphenyl)acetone, methoxy-2-propanone, glyoxylic acid,
benzyl glyoxylate, benzylacetone, methyl benzyl ketone,
methylcyclohexyl ketone, 2-decanone, dicyclohexyl ketone,
3,3-dimethyl-2-butanone, methyl isobutyl ketone, methyl isopropyl
ketone,2-methyl-3-heptanone, 5-methyl-3-heptanone,
6-methyl-5-hepten-2-one, 5-methyl-2-hexanone, 3-nonanone,
5-nonanone, 2-octanone, 3-octanone, 2-undecanone, 1,3-
dichloroacetone, 1-hydroxy-2-butanone, 3-hydroxy-2-butanone,
4-hydroxy-4-methyl-2-pentanone, 2-(1S)-adamanantone, anthrone,
bicyclo(3.2.0)hept-2-en-6-one, cis-bieyclo(3.3.0)octan-3,7-dione,
(1S)- (-)-camphor, p-chloranil, cyclobutanone,
1,3-cyclohexanedione, 1,4-cyclohexanedione monoethylene ketal,
dibenzosuberone, ethyl 4-oxocyclohexanecarboxylate, 9-fluorenone,
1,3-indandione, methyl- cyclohexanone, phenylcyclohexanone,
4-propylcyclohexanone, 1,2,3,4-tetrahydro-1-naphthalenone,
1,2,3,4-tetrahydro-2-naphthalenone, 3,3 ,5-trimethylcyclo-hexanone,
3-acetoxy-2-cyclohexen-1-one, benzylideneacetone, (R)-(-)-carvone,
(S)-(-)carvone, curcumin, 2-cyclohexen-1-one, 2,3-diphenyl-2-
cyclopropen-l-one, 2-hydroxy-3-methyl-2-cyclopentene-1-one,
isophorone, .alpha.-ionone, .beta.-ionone,
3-methoxy-2-cyclohexen-1-one, 3-methyl-2-cyclopenten-1-one,
3-methyl-3-penten-2-one, (R)-(+)-pulegone,
tetraphenyl-2,4-cyclopentadien-1-one,
2,6,6-trimethyl-2-cyclohexen-1,4-dione, 2-acetylbenzoic acid,
1-acetylnaphthalene, 2-acetylnaphthalene, 3'-aminoacetophenone,
4'-aminoacetophenone, 4'-cyclohexylacetophenone, 3',
4'-diacetoxyacetophenone, diacetylbenzene,
2',4'-dihydroxyacetophenone, 2',5'-dihydroxyacetophenone,
2',6'-dihydroxyacetophenone, 3,4-dimethoxyacetophenone,
2'-hydroxyacetophenone, 4'-hydroxyacetophenone,
3'-methoxyacetophenone, 4'-methoxyacetophenone,
2'-methylacetophenone, 4'-methylacetophenone, 2'-nitroacetophenone,
3'-nitroacetophenone, 4'-phenylacetophenone,
3',4',5'-trimethoxy-acetophenone, 4'-aminopropiophenone,
benzoylacetone, benzoylpropionic acid, benzylideneacetophenone,
cyclohexyl phenyl ketone, desoxybenzoin, 4',4'-dimethoxybenzil,
1,3-diphenyl-1,3-propanedione, ethylbenzoyl acetate, ethyl
phenylglyoxylate, 4'-hydroxypropiophenone, 1,3-indandione,
1-indanone, isopropyl phenyl ketone, 6-methoxy-1,2,3,4-
tetrahydronaphthalen-1-one, methylphenyl glyoxylate,
phenylglyoxylonitrile, 1-phenyl-1, 2-propanedione 2-oxime,
valerophenone, 2-acetyl-.gamma.-butyrolactone, 2-acetylpyrrole,
1-benzylpiperidin-4-one, dehydroacetic acid,
3,4-dihydro-4,4-dimethyl-2H-pyran-2-one, 1,4-dihydro-4-pyridinone,
N-eth-oxycarbonyl-4-piperidinone, 2-methyl furyl ketone,
5-hydroxy-2-hydroxymethyl-4H-pyran-4-one,
3-hydroxy-2-methyl-4-pyranone, 3-indolyl methyl ketone, isatin,
1-methyl-4-piperidinone, methyl 2-pyridyl ketone, methyl 3-pyridyl
ketone, methyl 4-pyridyl ketone, methyl 2-thienyl ketone, phenyl
2-pyridyl ketone, phenyl 4-pyridyl ketone,
tetrahydrofuran-2,4-dione, tetrahydro-4H-pyran-4-one,
2,2,6,6-tetramethyl-4-piperidone, xanthone, acenaphthene quinone,
pyruvic acid, (1R)-(-)-camphor quinone, (1S)-(+)-camphor quinone,
3,5-ditert.butyl-o-benzoquinone, 1,2-dihydroxy-3,4-
cyclobutendione, ethyl (2-amino-4-thiazolyl)glyoxylate, ethyl
pyruvate, 2,3-hexanedione, 3,4- hexanedione, 3-methyl-2-oxobutyric
acid, 3-methyl-2-oxovaleric acid, 4-methyl-2-oxovaleric acid, 2-
oxobutyric acid, 2,3-pentandione, 9,10-phenanthrene quinone,
acetoacetanilide,2-acetyl-y-butyrolactone, 2-acetylcyclo-pentanone,
allyl acetoacetate, benzoylacetone, tert.butyl acetoacetate,
1,3-cyclopentanedione, diethyl 3-oxoglutarate, dimethyl
acetylsuccinate, dimethyl 3-oxoglutarate,
1,3-diphenyl-1,3-propanedione, ethyl acetoacetate, ethyl
benzoylacetate, ethyl butyrylacetate, ethyl
2-oxocyclohexanecarboxylate, ethyl 2-phenylacetoacetate, methyl
acetoacetate, 2-methyl-1,3- cyclohexanedione,
2-methyl-1,3-cyclopentanedione, methyl isobutyrylacetate, methyl
3-oxopentanoate, methyl pivaloylacetate, 3-oxoglutaric acid,
tetrahydrofuran-2,4-dione, 2,2,6,6-tetramethyl-3,5-heptanedione,
3-benzoylpropionic acid, 1,4-cyclohexanedione, dimethyl
acetylsuccinate, ethyl levulinate, 2-aminoanthraquinone,
anthraquinone, p-benzoquinone, 1,4-dihydroxyanthraquinone,
1,8-dihydroxyanthraquinone, 2-ethylanthraquinone,
methyl-p-benzoquinone, 1,4-naphthoquinone,
tetramethyl-p-benzoquinone, 2,2-dimethyl-1,3-dioxan-4,6-dione,
2-benzoylbenzoic acid, 3-benzoyl-propionic acid,
5,6-dimethoxyphthataldehydic acid, levulinic acid, methyl
trans-4-oxo-2-pentenoate, phthalaldehydic acid, terephthalaidehydic
acid, dibutyl maleate, dibutyl succinate, dibutyl phthalate,
dicyclohexyl phthalate, diethyl acetamidomalonate, diethyl adipate,
diethyl benzylmalonate, diethyl butylmalonate,
diethylethoxymethylene-malonate, diethyl ethylmalonate, diethyl
fumarate, diethyl glutarate, diethyl isopropylidenemalonate,
diethyl maleate, diethyl malonate, diethyl methylmalonate, diethyl
oxalate, diethyl 3-oxoglutarate, diethyl phenylmatonate, diethyl
phthalate, diethyl pimelate, diethyl sebacate, diethyl suberate,
diethyl succinate, diisobutyl phthalate, dimethyl
acetylene-dicarboxylate, dimethyl acetylsuccinate, dimethyl
adipate, dimethyl 2-aminoterephthalate, dimethyl fumarate, dimethyl
glutaconate, dimethyl glutarate, dimethyl isophthalate, dimethyl
malonate, dimethylmethoxy-malonate, dimethyl methylenesuccinate,
dimethyl oxalate, dimethyl 3-oxoglutarate, dimethyl phthalate,
dimethyl succinate, dimethyl terephthalate, ethylene glycol
diacetate, ethylene glycol dimethacrylate, monoethyl fumarate,
monomethyl malonate, monoethyl adipate, monomethyl phthalate,
monomethyl pimelate, monomethyl terephthalate, 1,2-propylene glycol
diacetate, triethyl methanetricarboxylate, trimethyl
1,2,3-propanetricarboxylate, 3-acetoxy-2-cyclohexen-1-one, allyl
acetoacetate, allyl cyanoacetate, benzyl acetoacetate, tert.butyl
acetoacetate, butyl cyanoacetate, chlorogenic acid hemihydrate,
coumarin-3-carboxylic acid, diethyl
ethoxy-carbonylmethanephosphonate, dodecyl gallate, dodecyl
3,4,5-trihydroxybenzoate, (2,3-epoxypropyl) methacrylate,
(2-ethoxyethyl) acetate, ethyl acetamidocyanoacetate, ethyl
2-aminobenzoate, ethyl 3-aminopyrazol-4-carboxylate, ethyl
benzoxylacetate, ethyl butyrylacetate, ethyl cyanoacetate, ethyl
2-cyano-3-ethoxyacrylate, ethyl cyanoformate, ethyl
2-cyanopropionate, ethyl 3,3-diethoxypropionate, ethyl
1,3-dithian-2-carboxylate, ethyl 2-ethoxyacetate, ethyl
2-furancarboxylate, ethyl levulinate, ethyl mandelate, ethyl
gallate, ethyl 2-methyllactate, ethyl 4-nitrocinnamate, ethyl
oxamate, ethyl 2-oxocyclohexanecarboxylate, ethyl 4-oxocyclohexane-
carboxylate, ethyl 5-oxohexanoate, ethyl 2-phenylacetoacetate,
ethyl 4-piperidinecarboxylate, ethyl 2-pyridinecarboxylate, ethyl
3-pyridinecarboxylate, ethyl 4-pyridinecarboxylate, ethyl
thioglycolate, ethyl 3,4,5-trihydroxybenzoate, 2-hydroxyethyl
methacrylate, 2-hydroxypropyl methacrylate, 3-indole acetate,
2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, methyl
2-aminobenzoate, methyl 3-aminocrotonate, methyl cyanoacetate,
methyl 4-cyanobenzoate, methyl 4-formylbenzoate, methyl
2-furancarboxylate, methyl isobutyrylacetate, methyl
methoxyacetate, methyl 2-methoxybenzoate, methyl 3-oxopentanoate,
methyl phenylglyoxylate, methyl phenyl-sulfinylacetate, methyl
pivatoylacetate, methyl 3-pyridinecarboxylate, 5-nitrofurfurylidene
diacetate, propyl gallate, propyl 3,4,5-trihydroxybenzoate, methyl
3-methylthiopropionate, acetamide, acetani-lide, benzamide,
benzanilide, N,N-diethylacetamide, N,N-dimethylformamide,
N,N-diethyl-3-methyl-benzamide, diethyltoluamide,
N,N-dimethylacetamide, N,N-diphenylacetamide, N-methylformamide,
N-methylformanilide, N-acetylthiourea, adipic acid diamide,
2-aminobenzamide, 4-aminobenzamide, succinic acid diamide, malonic
acid diamide, N,N'-methylene diacrylamide, oxalic acid diamide,
pyrazine-2-carboxamide, pyridine-4-carboxamide,
N,N,N',N'-tetramethylsuccinic acid diamide,
N,N,N',N'-tetramethylglutaric acid diamide, acetoacetanilide,
benzohydroxamic acid, cyanoacetamide, 2-ethoxybenzamide, diethyl
acetamidomalonate, ethyl acetamidocyanoacetate, ethyl oxamate,
hippuric acid Na salt, N-(hydroxy-methyl)acrylamide,
L-(-)-lactarnide, 2'-nitroacetanilide, 3'- nitroacetanilide,
4'-nitroacetanilide, paracetamol, piperine, salicylanilide,
2-acetyl-.gamma.-butyrolactone, .gamma.-butyrolactone,
.epsilon.-caprolactone, dihydrocoumarin, 4-hydroxycoumarin,
2-(5H)-furanone, 2,5-dihydro-5-methoxy-2-furanone, phthalide,
tetrahydrofuran-2,4-dione, 2,2,6-trimethyl-1,3-dioxin-4-one,
.gamma.-valerolactone, 4-amino-1,3-dimethyluracil, barbituric acid,
O-benzyloxycarbonyl-N-hydroxysuccinimide, succinimide,
3,6-dimethyl-piperazin-2,5-dione, 5,5-diphenylhydantoin, ethyl
1,3-dioxoisoindoline-2-carboxylate, 9-fluorenylmethylsuccinimidyl
carbonate, hydantoin, maleimide,
3-methyl-1-phenyl-2-pyrazolin-5-one, 1-methyl-2-pyrrolidone,
methyluracil, 6-methyluracil, oxindole, phenytoin,
1-(2H)-phthalazinone, phthalimide, 2,5-piperazinedione,
2-piperidinone, 2-pyrrolidone, rhodanine, saccharin,
1,2,3,6-tetrahydrophthalimide,
1,2,3,4-tetrahydro-6,7-dimethoxyquinazolin-2,4-dione,
1,5,5-trimethyl-hydantoin, 1-vinyl-2-pyrrolidone, ditert.butyl
dicarbonate, diethyl carbonate, dimethyl carbonate, dimethyl
dicarbonate, diphenyl carbonate, 4,5-diphenyl-1,3-dioxol-2-one,
4,6- diphenylthieno-(3,4-d)-1,3-dioxo[-2-one 5,5-dioxide, ethylene
carbonate, magnesium methoxide methyl carbonate, monomethyl
carbonate Na salt, propenyl carbonate, N-allylurea,
azodicarbonamide, N-benzylurea, biuret, 1,1'-carbonyldiimidazol,
N,N-dimethylurea, N-ethylurea, N-formylurea, urea, N-methylurea,
N-phenylurea, 4-phenylsemicarbazide, tetramethylurea, semicarbazide
hydrochloride, diethyl azodicarboxylate, methyl carbamate,
1-(4-methoxyphenyl)-2-(2-methoxyphenoxy)ethanone and
1-(4-methoxyphenyl)-2-(2-methoxyphenoxy)ethanol.
[0065] Also preferred are anhydrides, such as the following:
[0066] Benzoic anhydride, benzene-1,2,4,5-tetracarboxylic
acid-1,2,4,5-dianhydride, 3,3',4,4'-benzophenonetetracarboxylic
anhydride, succinic anhydride, butyric anhydride, crotonic
anhydride, cis-1,2-cyclo-hexanedicarboxylic anhydride, ditert.butyl
dicarbonate, dimethyl dicarbonate, dodecenylsuccinic anhydride,
Epicon B 4400, acetic anhydride, glutaric anhydride, hexanoic
anhydride, isatoic anhydride, isobutyric anhydride, isovaleric
anhydride, maleic anhydride, 1,8-naphthalenedicarboxylic anhydride,
3-nitrophthalic anhydride, 5-norbomene-2,3-dicarboxylic anhydride,
phthalic anhydride, 2-phenylbutyric anhydride, pivalic anhydride,
propionic anhydride, cis-1,2,3,6-tetrahydrophthalic anhydride and
valeric anhydride.
[0067] Application Fields of the Oxidation and/or Bleaching System
According to the Invention are Above All:
[0068] I) the use in the bleaching of cellulose/wood pulp,
[0069] II) the use in the treatment of different wastewaters (pulp
and paper industry, other),
[0070] III) the use in the preparation of lignin solutions or gels,
of the corresponding binders/adhesives and of wood-based
composites,
[0071] IV) the use as enzymatic deinking system,
[0072] V) the use as oxidation systems in organic synthesis,
[0073] VI) the use as bleaching agent in detergents,
[0074] VII) the use as bleaching and/or oxidation system in textile
industry, inclusive stone washing and bleaching of fabrics and the
general oxidative treatment of wool (e.g. bleaching),
[0075] VIII) the use in coal liquefaction,
[0076] due to the fact, that the new oxidation and/or bleaching
system according to the invention doesn't exhibit the disadvantages
of pure chemical systems (e.g. environmental safety problems) or
other enzyme-based systems ( e.g. low performance, high costs).
[0077] It was surprisingly found that by the use of the new
oxidation and/or bleaching system according to the invention
comprising of
[0078] oxidoreductases such as laccases and/or
peroxidases--seperately or in combination--in the presence of their
respective co-substrates like O.sub.2, air, H.sub.2O.sub.2, organic
peroxides, peracids etc. and comprising of
[0079] enhancer compounds from the class of oxocarbons, from the
class of urazoles and hydrazides, from the class of hydantoins and
the class of nitril (Cyan)-compounds, and comprising additionally
of
[0080] carbonyl compounds such as ketones, aldehyds,
[0081] whereby the combination of enzyme, co-substrate, enhancer
compound and carbonyl compound generate active oxygen species like
dioxiranes, dioxetanes, peroxy-compounds etc. or form (according
e.g. to the literature: K. Deuchert et. al., Angewandte Chemie 90,
S. 927-938, 1978) also other reactive compounds or transition
states like radicals (kation radicals, anion radicals) or reactive
(red/ox-active) neutreal compounds as oxidizing and/or bleaching
agents
[0082] a very significant delignification of pulp, a bleaching of
high yield pulps, a bleaching of recycled wood fibres afterdeinking
processes an oxidative polymerisation of lignin or lignin-derived
substances including decolorisation and or detoxification during
treatment of chemical pulp or high yield pulp waste waters or a
decolorisation and or detoxification of other waste waters, an
oxidative polymerisation of the available polyphenyl-propan
substances during the production of wood-based composites etc. a
release of the dyed particles from fibres during a deinking process
and a liquefaction of coal could be obtained.
[0083] Furthermore it was surprisingly found that the new oxidation
and/or bleaching system according to the invention shows a
significant and selective oxidation efficiency during its use as
oxidizing agent in organic synthesis , shows a high bleaching
efficency as bleaching additive in detergents and shows a high
oxidation power (bleaching efficiency) during oxidative treatment
of textiles including wool.
[0084] The method described in DE 19820947.9-45 can be
distinguished from the present invention through the addition of
suitable ketone (generally aliphatic) coumpounds which are not used
there. No benzophenones, benzils and some other organic carbonyl
compounds which were described in the older application are used
due to the fact that they show no effect using the new system.
[0085] A further advantage of the new system is that no oxygen
pressure has to be applied.
[0086] For the first time a catalytic behaviour at high
delignification performance ( e.g. 30% kappa reduction at 200 g per
ton oxocarbon dosage) of the new system according to the invention
could also be shown, provided the addition of suitable ketone
compounds.,
[0087] Furthermore the addition of primary, secondary or tertiary
amines can be of some advantage (see literature: K. Deuchert et.
al., Angewandte Chemie 90, S. 927-938, 1978.
[0088] As combining systems in combination with the new oxidation
and/or bleaching system according to the invention the enzymatic
system HOS (hydrolase mediated oxidation system), described in
W098/59108, consisting of lipases or other hydrolases, peroxide,
ketones and fatty acids/fats, or enzyme-based systems, described in
DE 101 26 988.9 ca be used.
DESCRIPTION OF VARIOUS APPLICATIONS OF THE ENZYME COMPONENT SYSTEM
OF THE INVENTION
[0089] I) the use in the bleaching of cellulose/wood pulp,
[0090] II) the use in the treatment of different wastewaters (pulp
and paper industry, other),
[0091] IV) the use in the preparation of lignin solutions or gels,
of the corresponding binders/adhesives and of wood-based
composites,
[0092] IV) the use as enzymatic deinking system,
[0093] V) the use as oxidation systems in organic synthesis,
[0094] VI) the use as bleaching agent in detergents,
[0095] VII) the use as bleaching and/or oxidation system in textile
industry, inclusive stone washing and bleaching of fabrics and the
general oxidative treatment of wool (e.g. bleaching),
[0096] VIII) the use in coal liquefaction,
[0097] I) Use of the Enzymatic Oxidation and/or Bleaching System
According to the Invention in Pulp Bleaching
[0098] Wood pulp is currently produced mainly by the sulfate and
sulfite processes. By both processes, pulp is made by cooking at
high temperature and under pressure. The sulfate process involves
the addition of NaOH and Na.sub.2S, whereas the sulfite process
uses Ca(HSO.sub.3).sub.2, +SO.sub.2, although the sodium and
ammonium hydrogen sulfite salts are currently used because of their
higher solubility.
[0099] The main objective of all processes is the removal of lignin
from the plant material, wood or annual plants used.
[0100] The lignin, which together with the cellulose and
hemicellulose forms the main constituent of the plant material
(stalks and stems), must be removed, because it is otherwise not
possible to produce nonyellowing, mechanically highly resistant
papers.
[0101] The processes for making high yield wood pulp involve the
use of stone grinders (groundwood) or of refiners
(TMP=thermomechanical pulp) which after an appropriate pretreatment
(chemical, thermal or thermechemical) defibrillate the wood by
milling.
[0102] These wood pulps still contain most of the lignin. They are
used primarily for the production of newspapers, magazines etc.
[0103] The possibilities of using enzymes for lignin degradation
have been under investigation for several years. The mechanism of
action of such lignolytic systems was discovered only a few years
ago, when it became possible to obtain sufficient amounts of
enzymes from the white rotting fungus Phanerochaete chryosporium by
use of proper culturing
[0104] conditions and the addition of inductors. This is how the
hitherto unknown lignin peroxidases and manganese peroxidases were
detected. Because Phanerochaete chryosporium is a very effective
lignin degrader, attempts have been made to isolate its enzymes and
use them in purified form for lignin degradation. This was
unsuccessful, however, because it was found that the enzymes
primarily cause repolymerization of lignin and not its
degradation.
[0105] The same is true for other lignolytic enzyme species, such
as the laccases which degrade lignin oxidatively with the aid of
oxygen rather than hydrogen peroxide. It was found that similar
processes are at work in all cases, namely that radicals are formed
which then react with each other causing the mentioned
polymerization.
[0106] Currently, there are only processes based on the use of
in-vivo systems (fungal systems). Optimization attempts were
directed mainly toward biopulping and biobleaching.
[0107] By biopulping is meant the treatment of wood chips with live
fungal systems. There are two kinds of application forms:
[0108] 1 . Pretreating the wood chips before charging them to the
ref iners or milling for the purpose of saving energy in high yield
wood pulp production (for example, TMP or groundwood). Another
advantage is the usually achieved improvement of mechanical
properties of the stock, and a drawback is that the final
brightness is worse.
[0109] 2. Pretreating the wood chips (softwood/hardwood) before
wood pulp cooking (kraft process, sulfite process). Here, the
objective is to reduce the amount of digestion chemicals, to
improve digestion capacity and extended cooking. The advantages
include improved kappa number reduction following digestion
compared to digestion without pretreatment.
[0110] The drawbacks of these processes are clearly their long
treatment times (several weeks) and particularly the unsolved
problem of risk of contamination during the treatment, if it is
desired to omit the uneconomical sterilization of the wood
chips.
[0111] Biobleaching also uses in-vivo systems. Before bleaching,
the digested pulp (softwood/hardwood) is inoculated with the fungus
and treated for a period of days or weeks. Only after such a long
treatment time is it possible to observe a drop in kappa number and
a significant improvement in brightness, so that the process is
uneconomical for implementation in current bleaching sequences.
[0112] Another application, mostly carried out with immobilized
fungal systems, is the treatment of pulp production wastewaters,
particularly bleaching plant wastewaters, for the purpose of
decolorizing them and reducing the AOX value (reducing the amount
of chlorinated compounds in the wastewater, compounds which were
used for chlorine or chlorine dioxide bleaching). It is also known
to use hemicellulases and particularly xylanases and mannases as
bleach boosters.
[0113] These enzymes act mainly on the reprecipatated xylan, which
after the cooking process partly covers the residual lignin, for
the purpose of degrading it and thus improving accessibility to the
lignin of the bleaching chemicals (primarily chlorine dioxide) used
in the subsequent bleaching sequences. The savings in bleaching
chemicals demonstrated in the laboratory have been confirmed on a
large scale only to a limited extent so that this type of enzyme
must also be classified as a bleaching additive.
[0114] Patent application PCT/EP 87/00635 describes a system for
removing lignin from lignin-cellulose-containing material with
simultaneous bleaching. The system is based on the use of
lignolytic enzymes from white rotting fugi with the addition of
reducing agents, oxidants and phenolic compounds as mediators.
[0115] According to DE 4 008 893 C2, in addition to the redox
system, mimicking substances are added which simulate the active
center (prosthetic group) of lignolytic enzymes. In this manner, a
marked improvement in performance is achieved.
[0116] According to patent application PCT/EP 92/01086, additional
improvement is achieved by use of a redox cascade with the aid of
phenolic or nonphenolic aromatics "balanced" in terms of their
oxidation potential.
[0117] All three processes are limited in regard to their
applicability on an industrial scale in that they must be used at
low wood pulp consistency (up to a maximum of 4%) and, in the case
of the last two applications also by the risk of leaching out
metals when chelating agents are used, the metals possibly causing
peroxide decomposition in the subsequent peroxide bleaching
stages.
[0118] WO 94/12619, WO 94/12620 and WO 94/12621 disclose processes
in which the peroxidase activity is increased with enhancers.
Enhancers are characterized in WO 94/12619 in terms of their
half-life.
[0119] According to WO 94/12620, enhancers are characterized by the
formula A=N--N.dbd.B where N means nitrogene A and B are defined
cyclic groups. According to WO 94/12620, enhancers are organic
chemicals containing at least two aromatic rings of which at least
one is substituted with defined groups.
[0120] All three patent applications concern dye transfer
inhibition and the use of enhancers together with peroxidases as
detergent additives or detergent compositions used in the detergent
sector.
[0121] Although the applicability to lignin is mentioned in the
specification of the applications, our own tests with the
substances actually disclosed in these applications have shown that
the claimed mediators are ineffective in increasing the bleaching
action of peroxidases in the treatment of lignin-containing
materials!.
[0122] WO 94/29510 and WO 96/18770 describe a process for enzymatic
delignification whereby the enzymes are used together with
mediators. The mediators disclosed are, in general, compounds
characterized by the structure NO--, NOH-- or NRNOH.
[0123] Among the mediators disclosed in WO 94/29510 and WO
96/18770, 1-hydroxy-1H-benzotriazole (HOBT) gave the best
delignification results. HOBT, however, has several drawbacks:
[0124] it is available only at a relative high price and in
insufficient quantities, [0125] under deliginification conditions,
it reacts forming 1H-benzotriazole and other colored products, this
compound shows relatively low degradability and could, in large
amounts, present a pollution problem, [0126] to a certain degree,
it harms the enzymes, [0127] its delignification velocity is not
very high.
[0128] Other mediator of the described NO--, NOH-- and HRN--OH type
do not show most of these drawbacks, but still have the
disadvantage that a relatively large amount of chemicals must be
used and, particularly, that because of their physiological
reactivity they may not be entirely harmless (mostly because of
NO-- radical formation).
[0129] It is therefore desirable to provide systems for modifying,
degrading or bleaching lignin, lignin-containing materials or
similar substances, which do not have the said drawbacks or present
them only to a minor degree.
[0130] This can be reached using the new oxidation and/or bleaching
system according to the invention which doesn't show the mentioned
disadvantages, i.e. it could be shown quite surprisingly, that
using the enzyme-based system according to the invention at
suitable combination of the components better delignification and
bleaching results are achieved compared to the abovesaid other
enzymatic systems, and the said drawbacks are negligible.
[0131] IIa) Use of the Enzymatic Oxidation and/or Bleaching System
According to the Invention in the Enzymatic Treatment of Special
Waste Waters (Paper Industry Waste Waters from e.g. Groundwood
Plants or Refiner Plants)
[0132] IIb) Use in the Enzymatic Treatment of Other Industrial
Waste Waters
[0133] Unlike most enzymes, oxidases and peroxidases exhibit low
substrate specificity, namely they can convert a wide range of
substances, usually of phenolic nature. Without mediators, oxidases
as well as many peroxidases show the tendency to polymerize
phenolic substances via free radical-induced polymerization, a
property which is attributed, for example, to laccase, belonging to
the group of oxidases, also in nature. The ability to polymerize
appropriate substances, for example lignins, namely to increase the
size of the molecules involved by "coupling reactions", can be
utilized, for example, for the treatment of lignin-containing
wastewaters in the paper industry such as TMP wastewater
(wastewater from the production of thermomechanical pulp by means
of refiners) and of grinder wastewater from mechanical wood pulping
units.
[0134] The water-soluble lignin compounds (polyphenolpropanes)
contained in these wastewaters are mainly responsible for the high
COD (chemical oxygen demand) and cannot be removed by conventional
technology. In the water treatment plant and in the downstream
waters, they are not degraded at all or they are degraded only very
slowly. At very high concentrations, these compounds can even
inhibit the bacteria in a water treatment plant and thus create
problems.
[0135] In this application, the enzyme action can be observed
immediately by a rapid development of turbidity in the wastewater
being treated, caused by an enlargement and thus insolubilization
of lignin molecules. The target molecules (polymerized lignin) thus
enlarged in molecular weight by enzymatic catalysis can be removed
by appropriate treatments (by flocculation, by precipitation with,
for example, aluminum sulfate/sodium aluminate, optionally in the
presence of cationic or anionic polyelectrolytes or by
sedimentation). The wastewater then shows a markedly reduced COD.
Upon disposal, such wastewater causes less pollution, namely it
increases the certainty of remaining below the permissible COD
limits. Thus is particularly important for not infrequently used
"procedures" run at the limit.
[0136] For this treatment, for example with laccase, the cost of
removing the reaction products of the enzymatic treatment by
flocculation, sedimentation or precipitation or a combination of
several such methods constitutes by far the predominant part of the
overall cost of the process.
[0137] All other industrial wastewaters containing phenolic or, in
general, oxidizable substances (for example, lignin, dyes etc) can,
in principle, be treated with, for example, the abovesaid
oxidoreductases. Such treatment can be applied to wastewaters from
grape presses, olive presses, dyeing plants in the textile
industry, wastewaters from pulping plants etc. If at all possible,
to attain maximum efficiency, polluted streams should be treated
before they are combined with other wastewaters.
[0138] To this system are added other special compounds (
polymerization catalysts) which serve as condensation nuclei and
can substantially enhance lignin polymerization so that the main
objective of this enzymatic wastewater treatment, which is to use
the lowest possible amount of the cost-intensive precipitant, can
be attained.
[0139] Such compounds are normally phenols, phenol derivatives and
polycyclic phenols which have more than one oxidizable phenolic
group.
[0140] Such polymerisation catalysts, which are claimed here, are
also described in WO98/59108 and DE 10126988.9.
[0141] Also in this case we have found, quite surprisingly, that
when the new enzyme-based oxidation and/or bleaching system
according to the invention is used by employing a special
[0142] Also in this case we have found, quite surprisingly, that
when the new enzyme-based oxidation and/or bleaching system
according to the invention is used by employing a special
combination of the components, much higher efficiency in treatment
of the above mentioned waste waters than be attained than with the
above-described enzymatic systems.
[0143] III) Use of the Enzymatic Oxidation and/or Bleaching System
According to the Invention in the Preparation of Lignin Solutions
or Gels, of the Corresponding Binders/Adhesives and of Wood-Based
Composites
[0144] The object of the present invention is to provide a process
for enzymatic polymerization and/or modification of lignin or
lignin-containing materials, for example for use in the production
of wood compositions or wood-based composites such as, for example,
fiber board from disintegrated wood or particle board from wood
chips or wood pieces (chipboard, plywood, wood composite
beams).
[0145] It is known from the literature and patents, for example WO
94/01488, WO 93/23477, WO 93/25622 and DE 3 037 992 C2 that
laccases, lignin peroxidases or peroxidases can be used for this
purpose. The main drawbacks, particularly in the case of laccases
and lignin peroxidases, are the difficulty of preparing these
enzymes and the low yields even of genetically modified
systems.
[0146] We have now found, quite surprisingly, that. here, too, the
enzymatic oxidation and or bleaching syste of the invention shows
much better performance compared to the prior-art enzymatic systems
for the polymerization and/or modification of lignin and/or
lignin-containing materials.
[0147] To this end, the enzyme component system of the invention is
brought together with lignin (for example, with lignosulfates
and/or unevaporated or evaporated sulfite waste liquor and/or
sulfate lignin.fwdarw.kraft lignin, for example induline) and/or
with lignin-containing material. The lignin and/or the
lignin-containing material can either be preincubated at an
elevated pH, namely above pH 8 and preferably at a pH between 9.5
and 10.5, at 20 to 100.degree. C. (preferably at 60 to 100.degree.
C.) after which the pH is reduced to below pH 7, depending on the
optimum pH range for enzyme activity of the enzyme-based system or,
if the activity optimum of the enzyme-based system is on the
alkaline side, the system and the lignin and/or the
lignin-containing material are brought together immediately,
without pretreatment. The purpose of the pretreatment or treatment
under alkaline pH conditions is to utilize the substantially easier
solubilization of lignin at these higher pH values. This is a major
advantage for the use according to the invention, because it is
thus possible to work without an organic solvent.
[0148] In other words, the main purpose of the described bringing
together of the enzyme component system and the lignin and/or
lignin-containing material is to achieve activation of the
substrates (polyphenylpropanes) by oxidation, namely to convert the
lignin and/or the lignin-containing material by free
radical-induced polymerization (modification) into an activated and
active binder which then when brought together with the wood fibers
and/or wood parts to be bonded (cemented together) can be cured
under the action of pressure and elevated temperature to give solid
wood-based composites such as the abovesaid wood products, for
example fiber boards and particle boards. The main advantage
consists of reducing, or producing savings in, the amount of
urea-formaldehyde resins normally used, for example, for gluing in
the production of chipboard, which resins, besides being toxic,
have only limited moisture resistance, or of phenol-formaldehyde
resins which exhibit unfavorabie swelling properties and require
long pressing times (once again, besides the question of
toxicity).
[0149] The polymerizing and/or modifying action of the enzyme
component system can be additionally enhanced by addition of
certain chemical polymerization catalysts, for example
polydiphenylmethane diisocyanate (PMDI) and other polymerization
catalysts used also for the polymerization of lignin in
lignin-containing wastewaters. Such substances consist of phenols,
phenol derivatives or other polycyclic phenolic compounds with a
number of oxidizable hydroxyl groups, as already indicated
hereinabove (wastewater treatment).
[0150] IV) Use of the Enzymatic Oxidation and/or Bleaching System
According to the Invention as an Enzymatic Deinking System
[0151] In principle, by deinking, which is currently always run in
a conventional manner by flotation, is meant a two-step
process.
[0152] Its objective is to remove printing ink and other dye
particles from the waste paper. The waste paper used in most cases
is paper collected domestically and consists mainly of newspapers
and magazines.
[0153] In the first treatment step, the dye particles adhering to
the paper fibers are removed primarily by mechanical/chemical
means. This is accomplished by "recycling" the paper as a uniform
fibrous slurry, namely by disintegrating (comminuting) the waste
paper in pulpers, drums or the like with simultaneous addition of
chemicals capable of enhancing removal and preventing yellowing and
thus also acting as bleaching chemicals, namely sodium hydroxide
solution, fatty acid, water glass and hydrogen peroxide
(H.sub.2O.sub.2). Here, the fatty acid acts as a fiber dye particle
collector and in the second treatment step, the flotation, also as
foaming agent.
[0154] After the waste paper has been disintegrated and the said
chemicals have been allowed to act for a certain length of time,
the flotation is carried out in special flotation vessels by
injecting air. During this process, the dye particles adhere to the
foam bubbles and are removed together with the bubbles. The dye is
thus separated from the paper fibers. Currently, this operation is
preferably carried out at a neutral pH, which makes it necessary to
use certain detergents in place of the fatty acids.
[0155] It is known from the literature (WO 91/14820, WO 92/20857)
to use an oxidoreductase or laccase system characterized primarily
by the addition of special substances which cause the optimum pH
for the action of laccase obtained from Trametes versicolor, which
normally is in the range of about pH 4-5, to shift into the
slightly alkaline range (pH 8 to 8.7). This, on the one hand, is an
important prerequisite for use in the deinking system because of
the CaSO.sub.4 problems arising below pH 7 and, on the other, does
not optimize the action of laccase in the polymerizing or
depolymerizing sense, but only produces a certain swelling of the
fibers. Such swelling (which is one of the main actions of sodium
hydroxide in purely chemical deinking systems) is a primary
performance characteristic of the dye-removing mechanism.
[0156] The only other additives required for this enzymatie system
employing oxidoreductases are the detergents needed to produce
foam. Nearly all suitable detergents also exert a dye-removing
action. Moreover, in conventional deinking systems the use of
sodium hydroxide and peroxide improves brightness as a result of
the bleaching action of these chemicals. This bleaching action
cannot be achieved with the prior-art enzyme system because of the
nature of the system.
[0157] We have now found, quite surprisingly, that by appropriate
selection of the components the enzymatic oxidation and/or
bleaching system of the invention exceeds the efficiency of other
enzymatic deinking systems, particularly those with oxidoreductases
and those applied to lignin-containing deinked pulp and at least in
part compensates for the advantage of bleaching with purely
chemical systems.
[0158] This means that it is possible to provide a system offering
environmentally friendly deinking under neutral pH conditions and
thus better post-bleaching, better pulp properties etc and good
performance similar to that of purely chemical systems.
[0159] In this case, a further improvement of printing ink removal
can be attained by the aforesaid addition of special substances
mostly of a phenolic nature and, in particular, containing several
hydroxyl groups, which are also used as polymerization catalysts in
enzymatic wastewater treatment and general polymerization
reactions, as in the production of binders/adhesives from lignin or
lignin-containing substances primarily for the preparation of
wood-based composites.
[0160] V) Use of the Enzymatic Oxidation and/or Bleaching System
According to the Invention as an Oxidation System in Organic
Synthesis
[0161] Recently, enzymes have increasingly been used for chemical
reactions in organic synthesis. A few examples showing a variety of
oxidative reactions that can be carried out with enzymatic systems
can be found in: Preparative Biotransformations (Whole Cell and
Isolated Enzymes in Organic Synthesis), S. M. Roberts, K. Wiggins
and G. Casy, J. Wiley & Sons Ltd, 1992/93;
[0162] Organic Synthesis with Oxidative Systems, H. L. Holland,
VCH, 1992; and
[0163] Biotransformations in Organic Chemistry, K. Faber, Springer
Verlag [publisher], 1992:
[0164] 1) Hydroxylation Reactions
[0165] a) Synthesis of alcohols
[0166] b) Hydroxylation of steroids
[0167] c) Hydroxylation of terpenes
[0168] d) Hydroxylation of benzenes
[0169] e) Hydroxylation of alkanes
[0170] f) Hydroxylation of aromatic compounds
[0171] g) Hydroxylation of double bonds
[0172] h) Hydroxylation of nonactivated methyl groups
[0173] i) Dihydroxylation of aromatie compounds
[0174] 2) Oxidation of Unsaturated Aliphatics
[0175] a) Preparation of epoxides
[0176] b) Preparation of compounds by epoxidation
[0177] c) Preparation of arene oxides
[0178] d) Preparation of phenols
[0179] e) Preparation of cis-dihydrodiols
[0180] 3) Baeyer-Villiger Oxidations
[0181] a) Baeyer-Villiger conversion of steroids
[0182] 4) Oxidation of Heterocycles
[0183] a) Transformation of organic sulfides
[0184] a) Oxidation of sulfur compounds
[0185] b) Oxidation of nitrogen compounds (formation of N-oxides
etc.)
[0186] d) Oxidation of other heteroatoms
[0187] 5) Carbon-Carbon Dehydrogenation
[0188] a) Dehydrogenation of steroids
[0189] 6) Other Oxidation Reactions
[0190] a) Oxidation of alcohols and aldehydes
[0191] b) Oxidation of aromatic methyl groups to aldehydes
[0192] c) Oxidative coupling of phenols
[0193] c) Oxidative degradation of alkyl chains (.beta.-oxidation
etc.)
[0194] e) Formation of peroxides or percompounds
[0195] f) Initiation of free-radical induced chain reactions.
[0196] Here, too, we found, quite surprisingly, that with the aid
of the enzymatic oxidation and/or bleaching system of the invention
it is possible to carry out many oxidation reactions exemplified
hereinabove.
[0197] VI) Use of the Enzymatic Oxidation and/or Bleaching System
According to the Invention as Bleaching Agent in Detergents
[0198] Conventional bleaching systems in domestic detergents are
unsatisfactory, particularly in the low-temperature range. Below a
washing temperature of 60.degree. C., the standard bleaching agent,
i.e., H.sub.2O.sub.2/sodium perborate/sodium percarbonate must be
activated by the addition of chemical bleach activators, such as
TAED and/or SNOBS. Also, the need exists for more highly
biodegradable, bio-compatible bleaching systems and systems for
low-temperature washing that can be used in small amounts. Whereas
enzymes are already being used industrially for protein-starch-fat
solution and for fiber treatment in the washing process, no
enzymatic system is currently available for detergent bleaching. WO
1/05839 describes the use of different oxidative enzymes (oxidases
and peroxidases) to prevent dye transfer. As is known, peroxidases
are capable of "decolorizing" different pigments (3-hydroxyflavone
and betaine are decolorized by horseradish peroxidase and carotene
by peroxidase). Said patent application describes the
decolorization (also referred to as bleaching) of textile dyes
removed from the laundered goods and present in the washing liquor
(conversion of a colored substrate into a noncolored, oxidized
substance). In this case, the enzyme is said to have the advantage
over, for example, hypochlorite which attacks dyes in or on the
fabric, in that the enzyme decolorizes only the dissolved dyes.
Hydrogen peroxide or an appropriate precursor generating hydrogen
peroxide in situ participates in the catalysis of the
decolorization. The enzyme reaction can be enhanced somewhat by
addition of other oxidizable enzyme substrates, for example metal
ions such as Mn.sup.++, halide ions, such as Cl.sup.- or Br.sup.-
or organic phenols, such as p-hydroxycinnamic acid and
3,4-dichlorophenol. In this case, it is postulated that short-lived
radicals or other oxidized states of the added substrate are formed
and are responsible for the bleaching or other modification of the
colored substance.
[0199] U.S. Pat. No. 4,077,6768 describes the use of iron porphin,
hemin chloride, iron phthalocyanines or derivatives thereof
together with hydrogen peroxide for preventing dye transfer. These
substances, however, are rapidly destroyed by excess peroxide, and
for this reason hydrogen peroxide formation must occur in a
controlled fashion.
[0200] Processes are known from WO 94/12619, WO 94/12620 and WO
94/12621 whereby the activity of the peroxidase is enhanced by
means of enhancers. Such enhancers are characterized in WO 94/12620
in terms of their half-life. According to WO 94/12621, enhancers
are characterized by the formula A=N--N.dbd.B where N means
nitrogen and A and B are defined cyclic groups. According to WO
94/12620, enhancers are organic chemicals containing at least two
aromatic rings of which at least one is substituted with defined
groups. All three patent applications concern dye transfer
inhibition and the use of enhancers together with peroxidases as
detergent additives or detergent compositions used in the detergent
sector. The combination of these enhancers is limited to
peroxidases. The use of mixtures containing peroxidases is also
known from WO 92/18687. A special system of oxidases and of
appropriate substrates such as hydrogen peroxide is described in
German Unexamined Patent Application DE 42 31 761. German
Unexamined Patent Application DE 19 18 729 concerns another special
detergent system consisting of glucose and glucose oxidase or of
starch, aminoglucosidase and glucose oxidase (GOD) and of added
hydroxylamine or a hydroxylamine compound, wherein the
hydroxylamine or the derivatives thereof serve to inhibit the
catalase that is often present in GOD. Hydroxylamine and the
derivatives thereof have definitely not been described as mediator
additives.
[0201] Finally, WO 94/29425, DE 4445088.5 and WO 97/48786 concern
multicomponent bleaching systems for use with detergents and which
consist of oxidation catalysts and oxidants and of aliphatic,
cycloaliphatic, heterocyclic or aromatic compounds containing NO--,
NOH-- or H--NR--OH groups.
[0202] All hitherto known "enzymatically enhanced"
detergent-bleaching systems have the drawback that their cleaning
and bleaching action is still unsatisfactory and that the mediators
must be used in excessive amounts which may cause environmental and
economic problems.
[0203] We have now found, quite surprisingly, that the enzymatic
oxidation and/or bleaching system of the invention exceeds the
performance of the aforesaid oxidoreductase-mediator systems and
does not have the said drawbacks of the prior art,
[0204] VII) Use of the Enzymatic Oxidation and/or Bleaching System
According to the Invention in the Bleaching and/or Decolorization
of Textile Fabrics
[0205] Enzymes are currently being used to an increasing extent in
various applications in the textile industry, For example, the use
of amylases in the desizing process is of great importance, because
the use of strong acids, alkalies or oxidants is thereby
avoided.
[0206] Similarly, cellulases are used for biopolishing and
biostoning, a process which is mostly employed together with
conventional stone washing with pumice in the treatment of denim
fabrics for jeans to remove the indigo dye. WO 94/29510, WO
96/18770, DE 196 12 194 A1 and DE 44 45 088 A1 describe enzymatic
delignification processes which use enzymes together with
mediators. In general, the disclosed mediators are compounds with
the NO--, NOH-- or HRNOH structure. These systems, of course, are
restricted to use in pulp bleaching. Because the mechanisms
underlying lignin-removing pulp bleaching, and this is the process
involved here, are entirely different from those underlying the
decolorization, removal and/or "destruction" of denim dyes,
particularly indigo dyes, in the jeans producing sector, it is
entirely surprising that a number of substances of the said NO--,
NOH-- and HNROH types are also suitable for this application.
[0207] WO 97/06244 describes systems for the bleaching of pulp, for
dye transfer inhibition and for bleaching stains when used with
detergents, which systems employ enzymes (peroxidases, laccases)
and enzyme-enhancing (hetero-)aromatic compounds, such as nitroso
compounds etc. In this case, as in patents WO 94/12619, WO 94/12620
and WO 94/12621, only the above-described use is intended. The
mechanisms of stain decolorization in detergent bleaching or of dye
transfer inhibition are entirely different from those underlying
the decolorization, removal and/or "destruction" of indigo dyes,
as, for example, in denim treatment. Hence, it is quite surprising
that a number of substances of the said NO--, NOH-- and HNROH-types
are also suitable for this application.
[0208] Processes are known from said WO 94/12619, WO 94/12620 and
WO 94/12621 in which the activity of peroxidase is increased by use
of enhancers. Such enhancers are characterized in WO 94/12620 in
terms of their half-life. According to WO 94/12621, enhancers are
characterized by the formula A=N--N.dbd.B where N means nitrogen
and A and B are defined cyclic groups. According to WO 94/12621,
enhancers are organic chemicals containing at least two aromatic
rings of which at least one is substituted with defined groups.
[0209] All three applications concern (as already stated) dye
transfer inhibition and the use of enhancers together with
peroxidases as detergent additives or detergent compositions for
washing applications or in cellulose bleaching. The combinations of
these enhancers are restricted to use with peroxidases.
[0210] Moreover, oxidoreductases, primarily laccases, but also
peroxidases, are currently used, mainly for treating denim for
jeans.
[0211] It is known from patent application WO 96/12846 that laccase
and peroxidase+certain enhancers, mainly derivatives of
phenothiazine or phenoxazine, are used in two application forms in
the treatment of cellulose-containing fabrics, such as cotton,
viscose, rayon (artificial silk), ramie, linen, Tencelm, silk or
mixtures thereof or mixtures of these fabrics with synthetic
fibers, for example a mixture of cotton and spandex (stretch
denim), but mainly denim fabrics (mainly for use in jeans).
[0212] On the one hand, the system (oxidoreductases+enhancers) is
intended as a replacement for the conventional hypochlorite
bleaching of denim, usually after a stone washing pretreatment,
this enzymatic treatment providing only partial replacement of
hypochlorite, because the desired bleaching effect cannot be
attained.
[0213] On the other hand, the system can be used together with
cellulase in stone washing in place of the usual mechanical
treatment with pumice, and this represents an improvement over the
"treatment with cellulase only".
[0214] The main drawbacks of the system described in WO 96/12846
are the following, among others:
[0215] 1) To achieve the desired goal, laccase must be used in
considerable amounts (about 10 international units [IU]/g of
denim);
[0216] 2) In some cases, optimum treatment requires 2-3 hours;
[0217] 3) The preferred mediator (here phenothiazine-10-propionic
acid) must be used in an amount of about 2 to about 14 mg per gram
of denim, which represents a considerable cost;
[0218] 1) Buffer systems (about 0.1 mol/L) must be used, because
otherwise no performance can be achieved, and this also raises the
cost of the system. This, for example, is not required for the
system of the invention;
[0219] 2) The color of the enhancer component (long-lived radical)
causes "browning" of the fabric.
[0220] The general advantage of a laccase and/or oxidoreductase
system with enzyme action--enhancing compounds (enhancers,
mediators etc.) when used in the above-described treatment of
textiles (for example, jeans fabrics) consists, in an improved
system over the prior-art systems, in that fashion looks can be
achieved, which is not possible with conventional hypochlorite
bleaching.
[0221] The dyes normally used for jeans denim are vat dyes, such as
indigo or indigo derivatives, for example thioindigo, as well as
sulfur dyes. By use of such special enzymatic systems, it is
possible (as a result of the high specificity of such systems),
when a mixed dye system such as an indigo dye and a sulfur dye
system is present, to decolorize only the indigo dye, while the
sulfur dye is not oxidized. Depending on the enzyme
action-enhancing compound used, this can produce almost any desired
fabric color (for example, gray shades etc), which is often
desirable.
[0222] An additional advantage is that the enzymatic treatment is
substantially more gentle than bleaching with hypochlorite, and as
a result fiber damage is reduced.
[0223] In the stone washing process, the ecological effect is of
particular importance (in addition to the reduced fiber damage
caused by enzymes) considering, for example, that this purely
mechanical process produces about 1 kg of stone sludge per kg
ofjeans denim.
[0224] As can be seen from the prior art, for colored fabrics, in
particular, the textile industry has a great need for alternative
bleaching processes (alternatives to conventional hypochlorite
bleaching) and/or treatment methods as alternatives to stone
washing to achieve the bleached look, in the latter case also
because of the environmental pollution problems.
[0225] The present invention has for an object to minimize or
eliminate the drawbacks of the conventional processes: stone
washing/bleaching after stone washing or general bleaching of dyed
and/or undyed textile fabrics, particularly the pollution problems
and fiber damage, as well as the drawbacks of the known
oxidoreductase/enhancer systems (for example also NO-radical
formation etc) and also the lipase mediated oxidation systems.
[0226] Entirely surprisingly, we have now found that the enzymatic
ocxidation and/or bleaching systems of the invention exceeds the
performance of the aforesaid oxidoreductase-mediator sytems and
that it does not exhibit the said drawbacks of the prior art.
DETAILED DESCRIPTION OF THE OXIDATION AND/OR BLEACHING ACCORDING TO
THE INVENTION
[0227] I) Use in the Beaching of Pulp
[0228] The efficacy of the enzymatic oxidation and/or bleaching
system of the invention in the modification, degradation or
bleaching of lignin, lignin-containing materials or similar
substances is often even enhanced when Mg.sup.2+ ions are present
besides the said constituents. The Mg.sup.2+ ions can be derived,
for example, from a salt such as MgSO.sub.4. The Mg.sup.2+
concentration is in the range from 0.1 to 2 mg/g, and preferably
from 0.2 to 0.6 mg/g, of lignin-containing material.
[0229] In some cases, the efficacy of the enzyme component system
(ECS) of the invention can be increased even further by adding to
the system besides Mg.sup.2+ ions also complexing agents, for
example ethylenediaminetetraacetic acid (EDTA),
diethylenetriaminepentaacetic acid (DTPA),
hydroxyethylenediaminetriacetic acid (HEDTA),
diethylenetriaminepentamethylenephosphonic acid (DTMPA),
nitrilotri-acetic acid (NTA), polyphosphoric acid (PPA) etc. The
concentration of said complexing agents is in the range from 0.2 to
5 mg/g, and preferably from 1 to 3 mg/g, of the lignin-containing
material. Surprisingly, we have also found that for many wood pulps
an acid wash (pH 2 to 6 and preferably 2 to 5) or a Q step (pH 2 to
6 and preferably 2 to 5) preceding the ECS step causes a marked
decrease in kappa value compared to processing without this special
pretreatment. In the Q step, chelators usually employed for this
purpose (for example, EDTA or DTPA) are preferably used at a
concentration f rom 0.1 to 1% and particularly from 0.1 to
0.5%.
[0230] Reducing agents can be added at the same time, which with
the oxidants present give rise to a certain redox potential.
Suitable reducing agents are sodium bisulfite, sodium dithionite,
ascorbic acid, thio compounds, mercapto compounds or glutathione
etc.
[0231] It is also possible to add to the system radical generators
or radical scavengers (scavenging, for example, OH-- or OOH--
radicals). These can improve the interaction between the redox and
the radical mediators.
[0232] Additional metal salt can also be added to the reaction
solution. These are important in that they interact with chelators
as radical generators or redox centers. In the reaction solution,
the salts form cations. Such ions are, among others, Fe.sup.2+,
Fe.sup.3+, Mn.sup.2+, Mn.sup.3+, Mn.sup.4+, Cu.sup.1+, Cu.sup.2+,
Ca.sup.2+, Ti.sup.3+, Ce.sup.4+ and Al.sup.3+.
[0233] The chelates present in the solution can also serve as
mimicking substances for certain oxido-reductases, such as the
laccases (copper complexes) or for the lignin or manganese
peroxidases (heme complexes). By mimicking substances are meant
substances simulating the prosthetic groups of (in the present
case) oxidoreductases and, for example, capable of catalyzing
oxidation reactions.
[0234] Moreover, NaOCl can be added to the reaction mixture. This
compound can form singlet oxygen by interacting with hydrogen
peroxide.
[0235] Finally, it is also possible to use detergents. These
include nonionic, anionic, cationic and amphoteric surfactants.
Detergents improve the penetration of the enzymes and other
components into the fibers.
[0236] It may also be necessary to add polysaccharides and/or
proteins to the reaction mixture. Suitable polysaccharides are, in
particular, glucans, mannans, dextrans, levans, pectins, alginates
or vegetable gums, and suitable proteins are gelatins and albumins.
These substances serve mainly as protective colloids for the
enzymes.
[0237] Other proteins that can be added are proteases such as
pepsin, bromelain, papain etc. These substances can, among other
things, bring about the degradation of extensin
(hydroxyproline-rich protein) present in wood, thus improving
access to the lignin.
[0238] Other suitable protective colloids are amino acids,
monosaccharides, oligosaccharides, polyethylene glycol [PEG] types
of a wide range of molecular weights, polyethylene oxides,
polyethyleneimines and polydimethylsiloxanes.
[0239] It is also possible to add to the enzyme component system of
the invention substances capable of increasing the hydrophobicity
of the reaction mixture, thus bringing about the swelling of the
lignin and the fibers and which makes them more susceptible to
attack. Such substances are, for example, glycols, such as
propylene glycol and ethylene glycol, glycol ethers such as
ethylene glycol dimethyl ether etc., and solvents, for example,
alcohols such as methanol, ethanol, butanol, amyl alcohol,
cyclohexanol, benzyl alcohol and chlorohydrin, phenols such as
phenol, methylphenols and methoxyphenols, aldehydes such as
formaldehyde and chloral, mercaptans such as butyl mercaptan,
benzyl mercaptan and thioglycolic acid, organic acids such as
formic, acetic and chloroacetic acid, amines such as ammonia and
hydrazine, hydrotropic solvents, for example concentrated solutions
of sodium benzoate, other substances such as benzenes, pyridines,
dioxane, ethyl acetate, and other basic solvents such as
OH.sup.-/H.sub.2O or OH.sup.-/alcohol etc.
[0240] The process according to the invention can be used not only
for the delignification (bleaching) of sulfate, sulfite, organosolv
or other wood pulps or lignins, but also for the preparation of
wood pulp in general, whether from wood or annual plants, when it
is desired to carry out the defibrillation by the usual cooking
(digestion) process (possibly combined with mechanical processing
or pressure), namely by very gentle digestion, up to kappa numbers
in the range from about 50-120 kappa.
[0241] In the bleaching as in the preparation of wood pulps, the
treatment with the enzymatic system of the invention can be applied
once or several times, either before and/or after the washing and
extraction of the treated material with NaOH etc., or without these
intermediate steps, but also before and/or after pretreatment or
post-treatment steps, such as acid washing, Q-steps, alkaline
leaching or bleaching steps such as peroxide bleaching,
O.sub.2-enhanced peroxide steps, pressurized peroxide steps,
O.sub.2-delignification, Cl.sub.2-bleaching, CIO.sub.2-bleaching,
Cl.sub.2/CIO.sub.2-bleaching, peracid bleaching, peracid-enhanced
O.sub.2/peroxide bleaching, ozone bleaching, dioxirane bleaching,
reductive bleaching steps, other treatments such as swelling steps,
sulfonations, NO/NO.sub.2 treatments, nitrosylsulfuric acid
treatment, enzyme treatments, for example treatments with
hydrolases, such as cellulases and/or hemicellulases (for example,
xylanase, mannase etc) and/or amylases and/or pectinases and/or
proteinases and/or lipases and/or amidases and/or oxidoreductases
such as, for example, laccases and/or peroxidases etc., or several
combined treatments.
[0242] This results in substantially further reduced kappa values
and substantially increased brightness. Before the enzymatic system
treatment, it is also possible to insert an O.sub.2 step or, as
already mentioned, carry out an acid wash or a Q-step (chelation
step).
[0243] The invention will be further illustrated by way of the
following examples:
EXAMPLE 1
[0244] Enzymatic Bleaching with Laccase/Squaric
Aid/Acetylaceton
[0245] Pulp: Softwood (Sulfate Pulp)
[0246] 5 g, absolutely dry basis, of wood pulp (O.sub.2-delignified
softwood), pulp consistency 30% (about 17 g moist) was added to
solutions prepared as follows:
[0247] A) To 20 mL of tap water were added 0.1 kg squaric aid and 1
kg acetylaceton per ton pulp with agitation. The pH was adjusted
with sulfuric acid and/or sodium hydroxide solution so that, after
addition of the wood pulp and the enzyme, the pH was 4.5.
[0248] B) To 5 mL of tap water was added this amount of laccase
that an activity of 2 IU* per g pulp resulted. * 1U=conversion of 1
.mu.Mol syringaldazine/min/mg solid enzyme
[0249] Solutions A and B were combined and diluted to 33 mL. After
addition of the wood pulp, the material was mixed in a dough mixer
for 2 minutes. The material was then transferred to a reaction
vessel preheated to 45.degree. C. and was allowed to incubate 1-4
hours under atmospheric pressure.
[0250] The material was washed over a nylon screen (30 .mu.m) and
extracted for one hour at 60.degree. C., 2% consistency and using
8% NaOH per gram of wood pulp. The material was again washed after
which the kappa number was determined.
EXAMPLE 2
[0251] Enzymatic Bleaching With
Laccase/4-tert.-butylurazol/acetylaceton
[0252] Pulp: Softwood (Sulfate Pulp)
[0253] 5 g, absolutely dry basis, of wood pulp (O.sub.2-delignified
softwood), pulp consistency 30% (about 17 g moist) was added to
solutions prepared as follows:
[0254] A) To 20 mL of tap water were added 2 kg 4-tert.-butylurazol
and 1 kg acetylaceton per ton pulp with agitation. The pH was
adjusted with sulfuric acid and/or sodium hydroxide solution so
that, after addition of the wood pulp and the enzyme, the pH was
4.5.
[0255] B) To 5 mL of tap water was added this amount of laccase
that an activity of 2 IU* per g pulp resulted. * 1U=conversion of
1.mu.Mol syringaldazine/min/mg solid enzyme
[0256] Solutions A and B were combined and diluted to 33 mL. After
addition of the wood pulp, the material was mixed in a dough mixer
for 2 minutes. The material was then transferred to a reaction
vessel preheated to 45.degree. C. and was allowed to incubate 1-4
hours under atmospheric pressure.
[0257] The material was washed over a nylon screen (30 .mu.m) and
extracted for one hour at 60.degree. C., 2% consistency and using
8% NaOH per gram of wood pulp. The material was again washed after
which the kappa number was determined.
EXAMPLE 3
[0258] Enzymatic Bleaching With Laccase/Adipinic Acid
Dihydrazide/Acetylaceton
[0259] Pulp: Softwood (Sulfate Pulp)
[0260] 5 g, absolutely dry basis, of wood pulp (O.sub.2-delignified
softwood), pulp consistency 30% (about 17 g moist) was added to
solutions prepared as follows:
[0261] A) To 20 mL of tap water were added 2 kg adipinic acid
dihydrazide and 1 kg acetylaceton per ton pulp with agitation. The
pH was adjusted with sulfuric acid and/or sodium hydroxide solution
so that, after addition of the wood pulp and the enzyme, the pH was
4.5.
[0262] B) To 5 mL of tap water was added this amount of laccase
that an activity of 2 IU* per g pulp resulted. * 1U=conversion of 1
.mu.Mol syringaldazine/min/mg solid enzyme
[0263] Solutions A and B were combined and diluted to 33 mL. After
addition of the wood pulp, the material was mixed in a dough mixer
for 2 minutes. The material was then transferred to a reaction
vessel preheated to 45.degree. C. and was allowed to incubate 1-4
hours under atmospheric pressure.
[0264] The material was washed over a nylon screen (30 .mu.m) and
extracted for one hour at 60.degree. C., 2% consistency and using
8% NaOH per gram of wood pulp. The material was again washed after
which the kappa number was determined.
EXAMPLE 4
[0265] Enzymatic Bleaching With Laccase/Hydantoyl-Acetic
Acid/Acetylaceton
[0266] Pulp: Softwood (Sulfate Pulp)
[0267] 5 g, absolutely dry basis, of wood pulp (O.sub.2-delignified
softwood), pulp consistency 30% (about 17 g moist) was added to
solutions prepared as follows:
[0268] A) To 20 mL of tap water were added 2 kg hydantoyl-acetic
acid and 1 kg acetylaceton per ton pulp with agitation. The pH was
adjusted with sulfuric acid and/or sodium hydroxide solution so
that, after addition of the wood pulp and the enzyme, the pH was
4.5.
[0269] B) To 5 mL of tap water was added this amount of laccase
that an activity of 2 IU* per g pulp resulted. * 1U=conversion of 1
.mu.Mol syringaldazine/min/mg solid enzyme
[0270] Solutions A and B were combined and diluted to 33 mL. After
addition of the wood pulp, the material was mixed in a dough mixer
for 2 minutes. The material was then transferred to a reaction
vessel preheated to 45.degree. C. and was allowed to incubate 1-4
hours under atmospheric pressure.
[0271] The material was washed over a nylon screen (30 .mu.m) and
extracted for one hour at 60.degree. C., 2% consistency and using
8% NaOH per gram of wood pulp. The material was again washed after
which the kappa number was determined.
EXAMPLE 5
[0272] Enzymatic Bleaching With HRP/Dicyandiamide/Acetylaceton
[0273] Pulp: Softwood (Sulfate Pulp)
[0274] 5 g, absolutely dry basis, of wood pulp (O.sub.2-delignified
softwood), pulp consistency 30% (about 17 g moist) was added to
solutions prepared as follows:
[0275] A) To 20 mL of tap water were added 2 kg dicyandiamide and 1
kg acetylaceton per ton pulp with agitation. The pH was adjusted
with sulfuric acid and/or sodium hydroxide solution so that, after
addition of the wood pulp and the enzyme, the pH was 4.5.
[0276] B) To 5 mL of tap water was added 0.1 mg HRP (horseradish
peroxidase) per g pulp.
[0277] Solutions A and B were combined and diluted to 33 mL. After
addition of the wood pulp, the material was mixed in a dough mixer
for 2 minutes. The material was then transferred to a reaction
vessel preheated to 45.degree. C. and was allowed to incubate 1-4
hours under atmospheric pressure.
[0278] The material was washed over a nylon screen (30 .mu.m) and
extracted for one hour at 60.degree. C., 2% consistency and using
8% NaOH per gram of wood pulp. The material was again washed after
which the kappa number was determined.
[0279] EXAMPLE 6
[0280] Enzymatic Bleaching With
Laccase/Ethylcarbazate/Acetylaceton
[0281] Pulp: Softwood (Sulfate Pulp)
[0282] 5 g, absolutely dry basis, of wood pulp (O.sub.2-delignified
softwood), pulp consistency 30% (about 17 g moist) was added to
solutions prepared as follows:
[0283] A) To 20 mL of tap water were added 3 kg ethylcarbazate and
1 kg acetylaceton per ton pulp with agitation. The pH was adjusted
with sulfuric acid and/or sodium hydroxide solution so that, after
addition of the wood pulp and the enzyme, the pH was 4.5.
[0284] B) To 5 mL of tap water was added this amount of laccase
that an activity of 2 IU* per g pulp resulted. *1U=conversion of 1
.mu.Mol syringaldazine/min/mg solid enzyme
[0285] Solutions A and B were combined and diluted to 33 mL. After
addition of the wood pulp, the material was mixed in a dough mixer
for 2 minutes. The material was then transferred to a reaction
vessel preheated to 45.degree. C. and was allowed to incubate 1-4
hours under atmospheric pressure.
[0286] The material was washed over a nylon screen (30 .mu.m) and
extracted for one hour at 60.degree. C., 2% consistency and using
8% NaOH per gram of wood pulp. The material was again washed after
which the kappa number was determined.
* * * * *