WO2014061805A1 - L-アミノ酸の製造法 - Google Patents
L-アミノ酸の製造法 Download PDFInfo
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- WO2014061805A1 WO2014061805A1 PCT/JP2013/078373 JP2013078373W WO2014061805A1 WO 2014061805 A1 WO2014061805 A1 WO 2014061805A1 JP 2013078373 W JP2013078373 W JP 2013078373W WO 2014061805 A1 WO2014061805 A1 WO 2014061805A1
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- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
- C12P13/00—Preparation of nitrogen-containing organic compounds
- C12P13/04—Alpha- or beta- amino acids
- C12P13/08—Lysine; Diaminopimelic acid; Threonine; Valine
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- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
- C12N9/00—Enzymes; Proenzymes; Compositions thereof; Processes for preparing, activating, inhibiting, separating or purifying enzymes
- C12N9/93—Ligases (6)
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- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
- C12P13/00—Preparation of nitrogen-containing organic compounds
- C12P13/04—Alpha- or beta- amino acids
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- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12Y—ENZYMES
- C12Y602/00—Ligases forming carbon-sulfur bonds (6.2)
- C12Y602/01—Acid-Thiol Ligases (6.2.1)
- C12Y602/01003—Long-chain-fatty-acid-CoA ligase (6.2.1.3)
Definitions
- the present invention relates to a method for producing L-amino acids such as L-lysine using bacteria.
- L-amino acids are used in various fields such as seasonings, food additives, feed additives, chemical products, and pharmaceuticals.
- L-amino acids such as L-lysine are industrially produced by fermentation using L-amino acid producing bacteria such as Escherichia bacteria having L-amino acid producing ability.
- L-amino acid-producing bacteria strains isolated from nature and modified strains thereof are used. Examples of the method for producing L-lysine include the methods described in Patent Documents 1 to 4.
- saccharides such as glucose, fructose, sucrose, waste molasses and starch hydrolyzate are generally used as carbon sources.
- a method for producing L-amino acid by fermentation using fatty acid as a carbon source is also known.
- a method using an L-amino acid-producing bacterium belonging to the family Enterobacteriaceae having a mutant rpsA gene for example, a method using an L-amino acid-producing bacterium belonging to the family Enterobacteriaceae having a mutant rpsA gene (Patent Document 5), an enterobacteria modified so as to reduce the activity of UspA protein A method using an L-amino acid-producing bacterium belonging to the family (Patent Document 6), and a method using an L-amino acid-producing bacterium belonging to the family Enterobacteriaceae modified so as to enhance the ability to assimilate fatty acids (Patent Document 7). .
- Non-patent Document 1 Fatty acids are assimilated via an assimilation pathway called ⁇ -oxidation (Non-patent Document 1). Enzymes that catalyze ⁇ -oxidation are encoded by the fad regulon consisting of fadL, fadD, fadE, fadB, and fadA, and the expression of the fad regulon is suppressed by the transcription factor encoded by fadR (Non-patent Document 1). ).
- the fadD gene generates a fatty acyl-CoA from a long-chain fatty acid and encodes a protein taken up through the inner membrane (Non-patent Document 2).
- Non-patent Document 7 it is known that production of L-amino acids such as L-lysine and L-threonine can be improved by enhancing expression of the Escherichia coli fadD gene (Patent Document 7).
- Bacillus subtilis has the lcfA gene as a gene corresponding to the fadD gene (Non-patent Document 3).
- the protein encoded by the Bacillus subtilis lcfA gene shows only 39% identity to the protein encoded by the Escherichia coli fadD gene, and introduction of the lcfA gene into intestinal bacteria There is no known effect on L-amino acid production using as a carbon source.
- JP 10-165180 A Japanese Patent Application Laid-Open No. 11-192088 JP 2000-253879 A JP 2001-057896 A International Publication No. 2011/096554 pamphlet WO 2011/096555 pamphlet JP 2011-167071 A
- An object of the present invention is to develop a novel technique for improving L-amino acid producing ability of bacteria when using fatty acid as a carbon source, and to provide a method for producing L-amino acid using fatty acid as a carbon source.
- the present inventor has introduced the lcfA gene derived from Bacillus subtilis into the bacterium, thereby improving the ability of the bacterium to produce L-amino acids when fatty acids are used as a carbon source.
- the present invention has been completed by finding that it can be improved.
- a method for producing an L-amino acid comprising: Culturing a bacterium belonging to the family Enterobacteriaceae having the ability to produce L-amino acid in a medium containing a fatty acid, and collecting L-amino acid from the medium;
- the bacterium is a bacterium introduced with the lcfA gene;
- the lcfA gene is DNA selected from the group consisting of the following (A) to (D): (A) DNA encoding a protein comprising the amino acid sequence shown in SEQ ID NO: 18; (B) In the amino acid sequence shown in SEQ ID NO: 18, the amino acid sequence includes one or several amino acid substitutions, deletions, insertions, or additions.
- DNA encoding a protein having activity to be taken up through the membrane (C) DNA containing the base sequence shown in SEQ ID NO: 17; (D) hybridizes with a base sequence complementary to the base sequence shown in SEQ ID NO: 17 or a probe that can be prepared from the base sequence under stringent conditions, and generates fatty acyl-CoA from long-chain fatty acids; DNA encoding a protein having an activity of taking up through the inner membrane.
- Bacteria used in the method of the present invention are bacteria belonging to the family Enterobacteriaceae having the ability to produce L-amino acids. And a bacterium into which the lcfA gene has been introduced. The bacterium of the present invention has an ability to use fatty acid as a carbon source.
- bacteria having L-amino acid-producing ability means that a desired L-amino acid is produced when cultured in a medium containing fatty acids. Refers to a bacterium having an ability to accumulate in a medium or in a microbial cell to such an extent that it can be recovered.
- the bacterium having L-amino acid-producing ability may be a bacterium capable of accumulating a larger amount of the target L-amino acid in the medium than the unmodified strain.
- Non-modified strains include wild strains and parent strains.
- the bacterium having L-amino acid-producing ability is a bacterium that can accumulate the target L-amino acid in an amount of 0.5 g / L or more, more preferably 1.0 g / L or more in the medium. May be.
- L-amino acids include basic amino acids such as L-lysine, L-ornithine, L-arginine, L-histidine, L-citrulline, L-isoleucine, L-alanine, L-valine, L-leucine, glycine, etc.
- Aliphatic amino acids amino acids which are hydroxymonoaminocarboxylic acids such as L-threonine and L-serine, cyclic amino acids such as L-proline, aromatic amino acids such as L-phenylalanine, L-tyrosine and L-tryptophan, L- Examples thereof include sulfur-containing amino acids such as cysteine, L-cystine and L-methionine, acidic amino acids such as L-glutamic acid and L-aspartic acid, and amino acids having an amide group in the side chain such as L-glutamine and L-asparagine.
- the bacterium of the present invention may have an ability to produce two or more amino acids.
- the L-amino acid may be a free form, a salt thereof, or a mixture thereof.
- the salt include sulfate, hydrochloride, carbonate, ammonium salt, sodium salt, and potassium salt.
- amino acids are L-amino acids unless otherwise specified.
- NCBI National Center for Biotechnology Information
- the Escherichia bacterium is not particularly limited, but includes bacteria classified into the genus Escherichia by classification known to microbiologists.
- Escherichia bacteria include, for example, Neidhardt et al. (Backmann, B. J. 1996. Derivations and Genotypes of some mutant derivatives of Escherichia coli K-12, p. 2460-2488. Table 1.
- F. D. Nehard (ed.) “Escherichia, coli, and Salmonella, Cellular, and Molecular, Biology / Second Edition, American, Society, for Microbiology, Press, Washington, DC).
- bacteria belonging to the genus Escherichia include Escherichia coli.
- Specific examples of Escherichia coli include Escherichia coli W3110 (ATCC11027325) and Escherichia coli MG1655 (ATCC 47076) derived from the prototype wild-type strain K12.
- strains can be sold, for example, from the American Type Culture Collection (address 12301 Parklawn Drive, Rockville, Maryland 20852 P.O. Box 1549, Manassas, VA 20108, United States States of America). That is, each strain is given a registration number, and can be sold using this registration number (see http://www.atcc.org/). The registration number corresponding to each strain is described in the catalog of American Type Culture Collection.
- the bacteria belonging to the genus Enterobacter are not particularly limited, but include bacteria classified into the genus Enterobacter by classification known to microbiologists.
- Enterobacter bacteria include Enterobacter agglomerans and Enterobacter aerogenes.
- Specific examples of Enterobacter agglomerans include the Enterobacter agglomerans ATCC12287 strain.
- Specific examples of Enterobacter aerogenes include Enterobacter aerogenes ATCC13048 strain, NBRC12010 strain (Biotechonol Bioeng.2007 Mar 27; 98 (2) 340-348), AJ110637 (FERM BP-10955) strain .
- Enterobacter bacteria include those described in European Patent Application Publication No. EP0952221.
- Pantoea bacterium is not particularly limited, and examples include bacteria classified into the Pantoea genus by classification known to microbiologists.
- Pantoea bacteria include Pantoea ⁇ ⁇ ananatis, Pantoea stewartii, Pantoea agglomerans, and Pantoea citrea.
- Pantoea Ananatis AJ13355 (FERM BP-6614), AJ13356 (FERMFERBP-6615), AJ13601 (FERM BP-7207), SC17 (FERM ⁇ BP-11091) And SC17 (0) strain (VKPM B-9246).
- Pantoea bacterium also includes a bacterium reclassified as Pantoea in this way.
- Examples of the genus Erwinia include Erwinia amylovora and Erwinia carotovora.
- Examples of Klebsiella bacteria include Klebsiella planticola.
- An L-amino acid-producing bacterium belonging to the family Enterobacteriaceae belongs, for example, by imparting an L-amino acid-producing ability to a bacterium belonging to the above Enterobacteriaceae family, or belongs to the above Enterobacteriaceae family. It can be obtained by enhancing the ability of bacteria to produce L-amino acids.
- L-amino acid-producing ability can be imparted or enhanced by a method conventionally used for breeding amino acid-producing bacteria such as coryneform bacteria or Escherichia bacteria (Amino Acid Fermentation, Academic Publishing Center, Inc., 1986). (May 30, 1st edition issued, see pages 77-100). Examples of such methods include acquisition of auxotrophic mutants, acquisition of L-amino acid analog-resistant strains, acquisition of metabolic control mutants, and recombination with enhanced activity of L-amino acid biosynthetic enzymes. The creation of stocks. In the breeding of L-amino acid-producing bacteria, properties such as auxotrophy, analog resistance, and metabolic control mutation that are imparted may be single, or two or more.
- L-amino acid biosynthetic enzymes whose activities are enhanced in breeding L-amino acid-producing bacteria may be used alone or in combination of two or more.
- imparting properties such as auxotrophy, analog resistance, and metabolic control mutation may be combined with enhancing the activity of biosynthetic enzymes.
- auxotrophic mutant, an analog resistant strain, or a metabolically controlled mutant having L-amino acid production ability is subjected to normal mutation treatment of the parent strain or wild strain, and the auxotrophic, analog It can be obtained by selecting those exhibiting resistance or metabolic control mutations and having the ability to produce L-amino acids.
- normal mutation treatment include irradiation with X-rays and ultraviolet rays, and treatment with a mutation agent such as N-methyl-N′-nitro-N-nitrosoguanidine.
- the L-amino acid-producing ability can be imparted or enhanced by enhancing the activity of an enzyme involved in the target L-amino acid biosynthesis. Enhancing enzyme activity can be performed, for example, by modifying bacteria so that expression of a gene encoding the enzyme is enhanced. Methods for enhancing gene expression are described in WO00 / 18935 pamphlet, European Patent Application Publication No. 1010755, and the like. A detailed method for enhancing the enzyme activity will be described later.
- the L-amino acid-producing ability can be imparted or enhanced by reducing the activity of an enzyme that catalyzes a reaction that branches from the biosynthetic pathway of the target L-amino acid to produce a compound other than the target L-amino acid. It can be carried out.
- an enzyme that catalyzes a reaction that produces a compound other than the target L-amino acid by branching from the biosynthetic pathway of the target L-amino acid includes enzymes involved in the degradation of the target amino acid. It is. A method for reducing the enzyme activity will be described later.
- L-amino acid-producing bacteria and methods for imparting or enhancing L-amino acid-producing ability are given below.
- any of the modifications exemplified below for imparting or enhancing the properties of L-amino acid-producing bacteria and L-amino acid-producing ability may be used alone or in appropriate combination.
- L-lysine producing bacteria examples include a strain in which the activity of one or more enzymes selected from L-lysine biosynthetic enzymes are enhanced.
- enzymes include, but are not limited to, dihydrodipicolinate synthase (dapA), aspartokinase III (lysC), dihydrodipicolinate reductase (dapB), diaminopimelate Diaminopimelate decarboxylase (lysA), diaminopimelate dehydrogenase (ddh) (US Pat. No.
- dihydrodipicolinate reductase diaminopimelate decarboxylase, diaminopimelate dehydrogenase, phosphoenolpyruvate carboxylase, aspartate aminotransferase, diaminopimelate epimerase, aspartate semialdehyde dehydrogenase, tetrahydrodipicolinate succinylase, and succinyl diamino
- the activity of one or more enzymes selected from pimelate deacylase is enhanced.
- a gene (cyo) (EP 1170376 A) involved in energy efficiency, a gene encoding nicotinamide nucleotide transhydrogenase (pntAB) ( US Pat. No. 5,830,716), ybjE gene (WO2005 / 073390), or combinations thereof may have increased expression levels.
- Aspartokinase III (lysC) is subject to feedback inhibition by L-lysine.
- a mutant lysC gene encoding aspartokinase III that has been desensitized to feedback inhibition by L-lysine is used. It may be used (US Pat. No.
- the L-lysine-producing bacterium or the parent strain for deriving it is selected from enzymes selected from enzymes that catalyze reactions that branch off from the biosynthetic pathway of L-lysine to produce compounds other than L-lysine. Examples include strains in which the activity of the above enzymes is reduced or deficient. Such enzymes include, but are not limited to, homoserine dehydrogenase, lysine decarboxylase (US Pat. No. 5,827,698), and malic enzyme (WO2005 / 010175). .
- L-lysine-producing bacteria or parent strains for inducing them include mutants having resistance to L-lysine analogs.
- L-lysine analogs inhibit the growth of bacteria belonging to the family Enterobacteriaceae such as the genus Escherichia, but this inhibition is completely or partially released when L-lysine is present in the medium.
- the L-lysine analog is not particularly limited, and examples thereof include oxalysine, lysine hydroxamate, S- (2-aminoethyl) -L-cysteine (AEC), ⁇ -methyllysine, and ⁇ -chlorocaprolactam. Mutants having resistance to these lysine analogs can be obtained by subjecting bacteria belonging to the family Enterobacteriaceae to ordinary artificial mutation treatment.
- L-lysine-producing bacteria or parent strains for deriving them include, but are not limited to, E. coli AJ11442 (FERM BP-1543, NRRL B-12185; see U.S. Pat. No. 4,346,170) and E ... coli VL611. In these strains, feedback inhibition of aspartokinase by L-lysine is released.
- L-lysine-producing bacteria or parent strains for inducing them include E. coli WC196 strain.
- the WC196 strain was bred by conferring AEC resistance to the W3110 strain derived from E. coli K-12 (US Pat. No. 5,827,698).
- the WC196 strain was named E.
- L-lysine producing bacteria include E.coli WC196 ⁇ cadA ⁇ ldc and E.coli WC196 ⁇ cadA ⁇ ldc / pCABD2 (WO2006 / 078039).
- WC196 ⁇ cadA ⁇ ldc is a strain constructed by disrupting the cadA and ldcC genes encoding lysine decarboxylase from the WC196 strain.
- WC196 ⁇ cadA ⁇ ldc / pCABD2 is a strain obtained by introducing plasmid pCABD2 (US Pat. No. 6,040,160) containing a lysine biosynthesis gene into the WC196 ⁇ cadA ⁇ ldc strain.
- WC196 ⁇ cadA ⁇ ldc was named AJ110692, and on October 7, 2008, National Institute of Advanced Industrial Science and Technology, Patent Biological Depositary Center (currently, National Institute of Technology and Evaluation, Patent Biological Depositary Center, ZIP Code: 292-0818, Address: 2-5-8 120, Kazusa Kamashitsu, Kisarazu City, Chiba Prefecture, Japan) was deposited under the accession number FERM BP-11027.
- pCABD2 is a mutant dapA gene encoding dihydrodipicolinate synthase (DDPS) derived from E. coli having a mutation that is desensitized to feedback inhibition by L-lysine, and a mutation that is desensitized to feedback inhibition by L-lysine.
- DDPS dihydrodipicolinate synthase
- a mutant lysC gene encoding aspartokinase III derived from E. coli, dapB gene encoding dihydrodipicolinate reductase derived from E. coli, and diaminopimelate dehydrogenase derived from Brevibacterium lactofermentum Contains the ddh gene.
- L-threonine producing bacteria examples include a strain in which the activity of one or more enzymes selected from L-threonine biosynthetic enzymes are enhanced.
- enzymes include, but are not limited to, aspartokinase III (lysC), aspartate semialdehyde dehydrogenase (asd), aspartokinase I (thrA), homoserine kinase (thrB), threonine synthase ( threonine synthase) (thrC), aspartate aminotransferase (aspartate transaminase) (aspC).
- the L-threonine biosynthesis gene may be introduced into a strain in which threonine degradation is suppressed.
- strains in which threonine degradation is suppressed include E. coli TDH6 strain lacking threonine dehydrogenase activity (Japanese Patent Laid-Open No. 2001-346578).
- the activity of the L-threonine biosynthetic enzyme is inhibited by the final product L-threonine. Therefore, in order to construct an L-threonine-producing bacterium, it is preferable to modify the L-threonine biosynthetic gene so as not to receive feedback inhibition by L-threonine.
- the thrA, thrB, and thrC genes constitute a threonine operon, and the threonine operon forms an attenuator structure. Expression of the threonine operon is inhibited by isoleucine and threonine in the culture medium, and is suppressed by attenuation.
- Enhanced expression of the threonine operon can be achieved by removing the leader sequence or attenuator in the attenuation region (Lynn, S. P., Burton, W. S., Donohue, T. J., Gould, R. M., Gumport, R. I., and Gardner, J. F. J. Mol. Biol. 194: 59-69 (1987); WO02 / 26993; WO 2005/049808; WO2005 / 049808; WO2003 / 097839 reference).
- the threonine operon may be constructed so that a gene involved in threonine biosynthesis is expressed under the control of a lambda phage repressor and promoter (see European Patent No. 0593792).
- Bacteria modified so as not to be subjected to feedback inhibition by L-threonine can also be obtained by selecting a strain resistant to ⁇ -amino- ⁇ -hydroxyvaleric acid (AHV), which is an L-threonine analog.
- HAV ⁇ -amino- ⁇ -hydroxyvaleric acid
- the threonine operon modified so as not to be subjected to feedback inhibition by L-threonine is improved in the expression level in the host by increasing the copy number or being linked to a strong promoter.
- An increase in copy number can be achieved by introducing a plasmid containing a threonine operon into the host.
- An increase in copy number can also be achieved by transferring the threonine operon onto the host genome using a transposon, Mu phage, or the like.
- examples of a method for imparting or enhancing L-threonine production ability include a method for imparting L-threonine resistance to a host and a method for imparting L-homoserine resistance.
- the imparting of resistance can be achieved, for example, by enhancing the expression of a gene that imparts resistance to L-threonine or a gene that imparts resistance to L-homoserine.
- genes that confer resistance include rhtA gene (Res. Microbiol. 154: 123-135 (2003)), rhtB gene (European Patent Application Publication No. 0994190), rhtC gene (European Patent Application Publication No.
- L-threonine-producing bacteria or parent strains for deriving them include, but not limited to, E.Ecoli TDH-6 / pVIC40 (VKPM B-3996) (US Patent No. 5,175,107, US Patent) No. 5,705,371), E. coli 472T23 / pYN7 (ATCC 98081) (U.S. Pat.No. 5,631,157), E. coli NRRL-21593 (U.S. Pat.No. 5,939,307), E. coli FERM BP-3756 (U.S. Pat. ), E. coli FERM BP-3519 and FERM BP-3520 (U.S. Pat.No. 5,376,538), E.
- E. Examples include strains belonging to the genus Escherichia such as E. coli VL643 and VL2055 (EP1149911A), and E. coli VKPM B-5318 (EP0593792A).
- VKPM B-3996 is a strain obtained by introducing plasmid pVIC40 into TDH-6.
- the TDH-6 strain is sucrose-assimilating, lacks the thrC gene, and has a leaky mutation in the ilvA gene.
- the B-3996 strain has a mutation that imparts resistance to a high concentration of threonine or homoserine in the rhtA gene.
- Plasmid pVIC40 is a plasmid in which a mutant thrA gene encoding aspartokinase homoserine dehydrogenase I resistant to feedback inhibition by threonine and a thrA * BC operon containing a wild type thrBC gene are inserted into an RSF1010-derived vector (US Patent) No. 5,705,371).
- This mutant thrA gene encodes aspartokinase homoserine dehydrogenase I substantially desensitized to feedback inhibition by threonine.
- B-3996 was deposited on 19 November 1987 at the All Union Scientific Center of Antibiotics (Nagatinskaya Street 3-A, 117105 Moscow, Russia) under the deposit number RIA 1867. . This stock was also deposited on April 7, 1987 at Lucian National Collection of Industrial Microorganisms (VKPM) (1 Dorozhny proezd., 1 Moscow 117545, Russia) under accession number B-3996 Has been
- the strain VKPM B-5318 is non-isoleucine-requiring and retains the plasmid pPRT614 in which the control region of the threonine operon in the plasmid pVIC40 is replaced with a temperature-sensitive lambda phage C1 repressor and a PR promoter.
- VKPM B-5318 was assigned to Lucian National Collection of Industrial Microorganisms (VKPM) (1 Dorozhny proezd., 1 Moscow 117545, Russia) on May 3, 1990 under the accession number VKPM B-5318. Has been deposited internationally.
- the thrA gene encoding aspartokinase homoserine dehydrogenase I of E. coli has been revealed (nucleotide numbers 337-2799, GenBank accession NC_000913.2, gi: 49175990).
- the thrA gene is located between the thrL gene and the thrB gene in the chromosome of E. coli K-12.
- the thrB gene encoding homoserine kinase of Escherichia coli has been elucidated (nucleotide numbers 2801 to 3733, GenBank accession NC_000913.2, gi: 49175990).
- the thrB gene is located between the thrA gene and the thrC gene in the chromosome of E. coli K-12.
- the thrC gene encoding threonine synthase from E.coli has been elucidated (nucleotide numbers 3734 to 5020, GenBank accession NC_000913.2, gi: 49175990).
- the thrC gene is located between the thrB gene and the yaaX open reading frame in the chromosome of E. coli K-12.
- thrA * BC operon containing a mutant thrA gene encoding an aspartokinase homoserine dehydrogenase I resistant to feedback inhibition by threonine and a wild type thrBC gene is known in the threonine-producing strain E. coli VKPM B-3996. It can be obtained from plasmid pVIC40 (US Pat. No. 5,705,371).
- the rhtA gene of E. coli is present at 18 minutes of the E. coli chromosome close to the glnHPQ operon, which encodes an element of the glutamine transport system.
- the rhtA gene is the same as ORF1 (ybiF gene, nucleotide numbers 764 to 1651, GenBank accession number AAA218541, gi: 440181), and is located between the pexB gene and the ompX gene.
- the unit that expresses the protein encoded by ORF1 is called rhtA gene (rht: resistant toosehomoserine andeonthreonine (resistant to homoserine and threonine)).
- the asd gene of E. coli has already been clarified (nucleotide numbers 3572511 to 3571408, GenBank accession NC_000913.1, gi: 16131307), and can be obtained by PCR using primers prepared based on the nucleotide sequence of the gene ( White, TJ et al., Trends Genet., 5, 185 (1989)).
- the asd gene of other microorganisms can be obtained similarly.
- the aspC gene of E. ⁇ ⁇ coli has already been clarified (nucleotide numbers 983742 to 984932, GenBank accession NC_000913.1, gi: 16128895), and obtained by PCR using a primer prepared based on the nucleotide sequence of the gene be able to.
- the aspC gene of other microorganisms can be obtained similarly.
- L-arginine producing bacteria examples include a strain in which the activity of one or more enzymes selected from L-arginine biosynthesis enzymes are enhanced.
- enzymes include, but are not limited to, N-acetylglutamylphosphate reductase (argC), ornithine acetyltransferase (argJ), N-acetylglutamate kinase (argB), acetylornithine transaminase (argD), ornithine carbamoyltransferase ( argF), arginosuccinate synthetase (argG), arginosuccinate lyase (argH), carbamoyl phosphate synthetase (carAB).
- argC N-acetylglutamylphosphate reductase
- argJ ornithine acetyltransferase
- argB N-acetylglutamate kinas
- N-acetylglutamate synthase (argA) gene examples include mutant N-acetylglutamate synthase in which amino acid residues corresponding to the 15th to 19th positions of the wild type are substituted and feedback inhibition by L-arginine is released. It is preferable to use a gene to be encoded (European Application Publication No. 1170361).
- L-arginine-producing bacteria or parent strains for deriving them include, but are not particularly limited to, E. ⁇ ⁇ coli ⁇ 237 strain (VKPM B-7925) (US Patent Application Publication 2002/058315 A1), mutant N -Derivative strains that retain acetylglutamate synthase ( Russian patent application No. 2001112869), E. coli 382 strain (VKPM B-7926) (EP1170358A1), which has improved acetic acid-assimilating ability derived from 237 strains, and N -Strains belonging to the genus Escherichia such as E.
- E. coli arginine producing strain (EP1170361A1) into which an argA gene encoding acetylglutamate synthetase has been introduced.
- E. coli 237 shares were registered with VKPM B-7925 on April 10, 2000 at Lucian National Collection of Industrial Microorganisms (1 Dorozhny proezd., 1 Moscow 117545, Russia) And was transferred to an international deposit under the Budapest Treaty on May 18, 2001.
- E. coli 382 shares were awarded VKPM B-7926 to Lucian National Collection of Industrial Microorganisms (VKPM) (1 Dorozhny proezd., 1 Moscow 117545, Russia) on April 10, 2000 Deposited at
- L-arginine-producing bacteria or parent strains for inducing them include strains having resistance to amino acid analogs and the like.
- Such strains include, for example, ⁇ -methylmethionine, p-fluorophenylalanine, D-arginine, arginine hydroxamic acid, S- (2-aminoethyl) -cysteine, ⁇ -methylserine, ⁇ -2-thienylalanine, or Examples include Escherichia coli mutants having resistance to sulfaguanidine (see JP-A-56-106598).
- L-citrulline and L-ornithine-producing bacteria share a biosynthetic pathway with L-arginine.
- N-acetylglutamate synthase argA
- N-acetylglutamylphosphate reductase argC
- ornithine acetyltransferase argJ
- N-acetylglutamate kinase argB
- acetylornithine transaminase argD
- WO 2006-35831 By increasing the enzyme activity of deacetylase (argE), the ability to produce L-citrulline and / or L-ornithine can be imparted or enhanced (WO 2006-35831).
- L-histidine producing bacteria examples include strains in which the activity of one or more enzymes selected from L-histidine biosynthetic enzymes are enhanced.
- enzymes include, but are not limited to, ATP phosphoribosyltransferase (hisG), phosphoribosyl AMP cyclohydrolase (hisI), phosphoribosyl-ATP pyrophosphohydrolase (hisI), phosphoribosylformimino-5-aminoimidazole carboxamide ribotide
- isomerase examples include isomerase (hisA), amide transferase (hisH), histidinol phosphate aminotransferase (hisC), histidinol phosphatase (hisB), and histidinol dehydrogenase (hisD).
- L-histidine biosynthetic enzymes encoded by hisG and hisBHAFI are inhibited by L-histidine. Therefore, the ability to produce L-histidine can be conferred or enhanced, for example, by introducing a mutation that confers resistance to feedback inhibition in the ATP phosphoribosyltransferase gene (hisG) ( Russian Patent No. 2003677 and No. 2). 2119536).
- L-histidine-producing bacteria or parent strains for inducing them include, but are not limited to, E. coli 24 strain (VKPM B-5945, RU2003677), E. coli 80 strain (VKPM B-7270, RU2119536), E. coli NRRL B-12116-B-12121 (US Patent No. 4,388,405), E. coli H-9342 (FERM BP-6675) and H-9343 (FERM BP-6676) (US Patent No. 6,344,347) ), E. coli H-9341 (FERM BP-6674) (EP1085087), E. coli AI80 / pFM201 (US Pat. No.
- E. coli FERM-P 5038 and 5048 JP-A-56-005099
- E. coli strain into which an amino acid transporting gene was introduced EP1016710A
- sulfaguanidine DL-1,2,4-triazole-3- Examples include strains belonging to the genus Escherichia such as E. coli 80 strain (VKPM B-7270, Russian Patent No. 2119536) imparted resistance to alanine and streptomycin.
- Examples of the method for imparting or enhancing L-cysteine production ability include a method of modifying a bacterium so that the activity of one or more enzymes selected from L-cysteine biosynthesis enzymes is increased. .
- Examples of such an enzyme include, but are not limited to, serine acetyltransferase and 3-phosphoglycerate dehydrogenase.
- Serine acetyltransferase activity can be enhanced, for example, by introducing a mutant cysE gene encoding a mutant serine acetyltransferase resistant to feedback inhibition by cysteine into bacteria.
- Mutant serine acetyltransferases are disclosed, for example, in JP-A-11-155571 and US Patent Publication No. 20050112731.
- the 3-phosphoglycerate dehydrogenase activity can be enhanced by introducing, for example, a mutant serA gene encoding a mutant 3-phosphoglycerate dehydrogenase resistant to feedback inhibition by serine into bacteria.
- Mutant 3-phosphoglycerate dehydrogenase is disclosed, for example, in US Pat. No. 6,180,373.
- the method for imparting or enhancing L-cysteine production ability is selected from, for example, an enzyme that catalyzes a reaction that branches from the biosynthesis pathway of L-cysteine to produce a compound other than L-cysteine.
- an enzyme that catalyzes a reaction that branches from the biosynthesis pathway of L-cysteine to produce a compound other than L-cysteine Alternatively, a method of modifying the bacterium so that the activity of the further enzyme is reduced can also be mentioned.
- examples of such enzymes include enzymes involved in the degradation of L-cysteine.
- the enzyme involved in the degradation of L-cysteine is not particularly limited, but cystathionine- ⁇ -lyase (metC) (Japanese Patent Laid-Open No. 11-155571, Chandra et.
- examples of methods for imparting or enhancing L-cysteine production ability include enhancing the L-cysteine excretion system and enhancing the sulfate / thiosulfate transport system.
- Proteins of the L-cysteine excretion system include proteins encoded by the ydeD gene (JP 2002-233384), proteins encoded by the yfiK gene (JP 2004-49237), emrAB, emrKY, yojIH, acrEF, bcr, And each protein encoded by each gene of cusA (Japanese Patent Laid-Open No.
- sulfate / thiosulfate transport system protein examples include proteins encoded by the cysPTWAM gene cluster.
- L-cysteine-producing bacteria or parent strains for deriving them include, but are not limited to, E. coli JM15 (US) transformed with various cysE alleles encoding a feedback inhibition resistant serine acetyltransferase. (Patent No. 6,218,168, Russian Patent Application No. 2003121601), E. coli W3110 (US Pat.No. 5,972,663) having an overexpressed gene encoding a protein suitable for excretion of a substance toxic to cells, cysteine desulfide Examples include strains belonging to the genus Escherichia such as E. coli strain (JP11155571A2) in which the lyase activity has been reduced and E. coli W3110 (WO0127307A1) in which the activity of the transcription regulator of the positive cysteine regulon encoded by the cysB gene has been increased.
- L-methionine producing bacteria examples include, but are not particularly limited to, L-threonine-requiring strains and mutants having resistance to norleucine (Japanese Patent Laid-Open No. 2000-139471). issue).
- examples of L-methionine-producing bacteria or parent strains for deriving them also include strains that retain mutant homoserine transsuccinylase that is resistant to feedback inhibition by L-methionine (Japanese Patent Laid-Open No. 2000-139471). , US20090029424).
- L-methionine is biosynthesized with L-cysteine as an intermediate, L-methionine production ability can be improved by improving L-cysteine production ability (Japanese Patent Laid-Open No. 2000-139471, US20080311632).
- L-methionine-producing bacteria or parent strains for inducing them include, for example, E. coli AJ11539 (NRRL B-12399), E. coli AJ11540 (NRRL B-12400), E. coli AJ11541 (NRRL B-12401), E. coli AJ11542 (NRRL B-12402) (British Patent No. 2075055), E. coli 218 strain (VKPM B-8125) having resistance to norleucine, an analog of L-methionine (Russian Patent No. 2209248) No.), 73 shares (VKPM B-8126) (Russian Patent No. 2215782), E.
- coli AJ13425 (FERM P-16808) (Japanese Patent Laid-Open No. 2000-139471).
- the AJ13425 strain lacks a methionine repressor, weakens intracellular S-adenosylmethionine synthetase activity, and produces intracellular homoserine transsuccinylase activity, cystathionine ⁇ -synthase activity, and aspartokinase-homoserine dehydrogenase II.
- L-threonine-requiring strain derived from E. coli W3110 with enhanced activity.
- L-leucine producing bacteria examples include strains in which the activity of one or more enzymes selected from L-leucine biosynthesis enzymes are enhanced.
- examples of such an enzyme include, but are not limited to, an enzyme encoded by a gene of leuABCD operon.
- a mutant leuA gene US Pat. No. 6,403,342
- isopropyl malate synthase from which feedback inhibition by L-leucine has been released can be suitably used.
- the L-leucine-producing bacterium or the parent strain for deriving the L-leucine-producing bacterium is a leucine-resistant E. coli strain 57 (for example, 57 strain (VKPM B-7386, U.S. Patent No. 6,124,121)) E. coli strains resistant to leucine analogs such as ⁇ , 2-thienylalanine, 3-hydroxyleucine, 4-azaleucine, 5,5,5-trifluoroleucine (Japanese Patent Publication No. 62-34397 and JP-A-8-70879) ), E. coli strains obtained by the genetic engineering method described in WO96 / 06926, E. coli H-9068 (JP-A-8-70879), and other strains belonging to the genus Escherichia.
- E. coli strain 57 for example, 57 strain (VKPM B-7386, U.S. Patent No. 6,124,121)
- Examples of the method for imparting or enhancing L-isoleucine producing ability include a method of modifying a bacterium so that the activity of one or more enzymes selected from L-isoleucine biosynthesis enzymes is increased.
- Examples of such an enzyme include, but are not limited to, threonine deaminase and acetohydroxy acid synthase (JP-A-2-458, FR 0356739, and US Pat. No. 5,998,178).
- L-isoleucine-producing bacteria or parent strains for inducing them include mutants having resistance to 6-dimethylaminopurine (Japanese Patent Laid-Open No. 5-304969), isoleucine analogs such as thiisoleucine and isoleucine hydroxamate. Examples include, but are not limited to, mutant strains having resistance, and mutant strains having resistance to DL-ethionine and / or arginine hydroxamate (Japanese Patent Laid-Open No. 5-130882).
- L-valine producing bacteria examples include a strain in which the activity of one or more enzymes selected from L-valine biosynthesis enzymes is enhanced.
- enzymes include, but are not limited to, enzymes encoded by genes of ilvGMEDA operon and ilvBNC operon.
- ilvBN encodes acetohydroxy acid synthase
- ilvC encodes isomeroreductase (WO 00/50624).
- the ilvGMEDA operon and the ilvBNC operon are subject to expression suppression (attenuation) by L-valine, L-isoleucine, and / or L-leucine.
- the threonine deaminase encoded by the ilvA gene is an enzyme that catalyzes the deamination reaction from L-threonine to 2-ketobutyric acid, which is the rate-limiting step of the L-isoleucine biosynthesis system. Therefore, for L-valine production, it is preferable that the ilvA gene is disrupted and the threonine deaminase activity is reduced.
- the L-valine-producing bacterium or the parent strain for deriving it is selected from an enzyme that catalyzes a reaction that produces a compound other than L-valine by branching from the biosynthetic pathway of L-valine.
- a strain in which the activity of the above enzyme is reduced is also mentioned.
- enzymes include, but are not limited to, threonine dehydratase involved in L-leucine synthesis and enzymes involved in D-pantothenic acid synthesis (International Publication No. 00/50624).
- L-valine-producing bacteria or parent strains for deriving the same include, but are not limited to, Escherichia such as E. coli strain (US Pat. No. 5,998,178) strain modified to overexpress the ilvGMEDA operon. Examples include strains belonging to the genus.
- examples of L-valine-producing bacteria and parent strains for inducing them include strains having mutations in aminoacyl t-RNA synthetases (US Pat. No. 5,658,766).
- examples of such a strain include E. coli VL1970 having a mutation in the ileS gene encoding isoleucine tRNA synthetase.
- E. coli VL1970 was assigned to Lucian National Collection of Industrial Microorganisms (VKPM) (1 Dorozhny proezd., 1 Moscow 117545, Russia) on June 24, 1988 under the accession number VKPM B-4411 It has been deposited.
- examples of L-valine-producing bacteria or parent strains for deriving the same also include mutant strains (WO96 / 06926) that require lipoic acid for growth and / or lack H + -ATPase.
- Examples of the L-glutamic acid-producing bacterium or the parent strain for inducing it include a strain in which the activity of one or more enzymes selected from L-glutamic acid biosynthetic enzymes are enhanced.
- enzymes are not particularly limited, but include glutamate dehydrogenase (gdhA), glutamine synthetase (glnA), glutamate synthetase (gltBD), isocitrate dehydrogenase (icdA), aconitate hydratase (acnA, acnB), citrate Synthase (gltA), methyl citrate synthase (prpC), phosphoenol pyruvate carbocilase (ppc), pyruvate dehydrogenase (aceEF, lpdA), pyruvate kinase (pykA, pykF), phosphoenol pyruvate synthase (ppsA)
- Strains belonging to the family Enterobacteriaceae modified to increase expression of citrate synthetase gene, phosphoenolpyruvate carboxylase gene, and / or glutamate dehydrogenase gene include those disclosed in EP1078989A, EP955368A, and EP952221A Can be mentioned.
- Examples of strains belonging to the family Enterobacteriaceae that have been modified to increase the expression of the Entner-Doudoroff pathway genes (edd, eda) include those disclosed in EP1352966B.
- L-glutamic acid-producing bacteria or parent strains for deriving the same are reduced or deficient in the activity of enzymes that catalyze reactions that branch off from the biosynthetic pathway of L-glutamic acid to produce compounds other than L-glutamic acid.
- enzymes that catalyze reactions that branch off from the biosynthetic pathway of L-glutamic acid to produce compounds other than L-glutamic acid.
- Such enzymes include, but are not limited to, isocitrate triase (aceA), ⁇ -ketoglutarate dehydrogenase (sucA), phosphotransacetylase (pta), acetate kinase (ack), acetohydroxy acid synthase (ilvG ), Acetolactate synthase (ilvI), formate acetyltransferase (pfl), lactate dehydrogenase (ldh), glutamate decarboxylase (gadAB), succinate dehydrogenase (sdhABCD), 1-pyrroline-5-carboxylate dehydrogenase (putA) Can be mentioned.
- aceA isocitrate triase
- sucA ⁇ -ketoglutarate dehydrogenase
- pta phosphotransacetylase
- ack acetate kinase
- ack acetohydroxy acid synthase
- ilvI Ace
- Escherichia bacteria with reduced or deficient ⁇ -ketoglutarate dehydrogenase ( ⁇ KGDH) activity and methods for obtaining them are described in US Pat. Nos. 5,378,616 and 5,573,945.
- a method for reducing or eliminating ⁇ -ketoglutarate dehydrogenase activity in enteric bacteria such as Pantoea bacteria, Enterobacter bacteria, Klebsiella bacteria, Erwinia bacteria, and the like are disclosed in U.S. Patent No. 6,197,559, U.S. Patent No. 6,682,912, This is disclosed in US Pat. No. 6,331,419, US Pat. No. 8,129,151, and WO2008 / 075483.
- bacteria belonging to the genus Escherichia with reduced or deficient ⁇ -ketoglutarate dehydrogenase activity include the following.
- E. coli W3110sucA Kmr
- E. coli AJ12624 (FERM BP-3853)
- E. coli AJ12628 (FERM BP-3854)
- E. coli AJ12949 (FERM BP-4881)
- E. coli W3110sucA is a strain obtained by disrupting the ⁇ -ketoglutarate dehydrogenase gene (hereinafter also referred to as "sucA gene") of E. coli W3110. This strain is completely deficient in ⁇ -ketoglutarate dehydrogenase activity.
- Pantoea ananatis AJ13355 strain (FERM BP-6614), SC17 strain (FERM BP-11091), SC17 (0) strain (VKPM B-9246)
- Pantoea bacteria such as
- the AJ13355 strain is a strain isolated as a strain capable of growing on a medium containing L-glutamic acid and a carbon source at low pH from soil in Iwata City, Shizuoka Prefecture.
- the SC17 strain is a strain selected from the AJ13355 strain as a low mucus production mutant (US Pat. No. 6,596,517).
- L-glutamic acid-producing bacteria or parent strains for inducing them also include Pantoea bacteria with reduced or deficient ⁇ -ketoglutarate dehydrogenase activity.
- Pantoea bacteria with reduced or deficient ⁇ -ketoglutarate dehydrogenase activity examples include AJ13356 (US Pat. No. 6,331,419) which is an ⁇ KGDH-E1 subunit gene (sucA) deficient strain of AJ13355 strain, and SC17sucA (US Pat. No. 6,596,517) which is a sucA gene deficient strain of SC17 strain. Is mentioned.
- AJ13356 was founded on February 19, 1998, National Institute of Biotechnology, National Institute of Advanced Industrial Science and Technology (currently, National Institute for Product Evaluation Technology, Patent Biological Deposit Center, Postal Code: 292-0818, Address: Kisarazu City, Chiba Prefecture, Japan No. 2-5-8 120, Kazusa Kamashita) was deposited under the deposit number FERM P-16645, transferred to an international deposit under the Budapest Treaty on January 11, 1999, and given the deposit number FERM BP-6616. . The SC17sucA strain was also granted the private number AJ417.
- Patent Biological Depositary Center On February 26, 2004, the National Institute of Advanced Industrial Science and Technology, Patent Biological Depositary Center (currently the National Institute of Technology and Evaluation, Patent Biological Depositary Center, ZIP Code: 292 -0818, Address: 2-5-8 120, Kazusa Kamashi, Kisarazu City, Chiba Prefecture, Japan), deposited under the accession number FERM BP-08646.
- AJ13355 was identified as Enterobacter agglomerans at the time of its isolation, but has recently been reclassified as Pantoea Ananatis by 16S rRNA sequencing. Therefore, AJ13355 and AJ13356 are deposited as Enterobacter agglomerans in the depository, but are described as Pantoea ananatis in this specification.
- L-glutamic acid-producing bacteria or parent strains for inducing them include Pantoea ananatis SC17sucA / RSFCPG + pSTVCB strain, AJ13601 strain, NP106 strain, and NA1 strain.
- the SC17sucA / RSFCPG + pSTVCB strain is different from the SC17sucA strain in that the plasmid RSFCPG containing the citrate synthase gene (gltA), phosphoenolpyruvate carboxylase gene (ppc), and glutamate dehydrogenase gene (gdhA) derived from Escherichia coli, and Brevi
- This is a strain obtained by introducing a plasmid pSTVCB containing a citrate synthase gene (gltA) derived from bacteria lactofermentum.
- the AJ13601 strain was selected from the SC17sucA / RSFCPG + pSTVCB strain as a strain resistant to a high concentration of L-glutamic acid at low pH.
- the NP106 strain is a strain obtained by removing the plasmid RSFCPG + pSTVCB from the AJ13601 strain.
- AIST National Institute of Advanced Industrial Science and Technology
- Patent Biological Deposit Center currently the National Institute for Product Evaluation Technology, Patent Biological Deposit Center, ZIP Code: 292-0818, Address: Japan No.
- L-glutamic acid-producing bacteria or parent strains for inducing them include strains in which both ⁇ -ketoglutarate dehydrogenase (sucA) activity and succinate dehydrogenase (sdh) activity are reduced or deficient (JP 2010) -041920).
- specific examples of such a strain include, for example, a pantoea ananatis NA1 sucAsdhA double-deficient strain (Japanese Patent Laid-Open No. 2010-041920).
- auxotrophic mutants examples include, but are not limited to, strains belonging to the genus Escherichia such as E. coli VL334thrC + (VKPM B-8961) (EP 1172433).
- E. coli VL334 (VKPM) B-1641) is an L-isoleucine and L-threonine auxotroph having a mutation in the thrC gene and the ilvA gene (US Pat. No. 4,278,765).
- VL334thrC + is an L-isoleucine-requiring L-glutamic acid-producing bacterium obtained by introducing a wild type allele of the thrC gene into VL334.
- the wild type allele of the thrC gene was introduced by a general transduction method using bacteriophage P1 grown in cells of wild type E.Ecoli K12 strain (VKPM B-7).
- examples of L-glutamic acid-producing bacteria or parent strains for inducing them also include strains resistant to aspartic acid analogs. These strains may be deficient in ⁇ -ketoglutarate dehydrogenase activity, for example.
- examples of strains resistant to aspartate analogs and lacking ⁇ -ketoglutarate dehydrogenase activity include, for example, E.768coli AJ13199 (FERM BP-5807) (US Patent No. 5.908,768), and L-glutamate resolution FFRM P-12379 (US Patent No. 5,393,671), AJ13138 (FERM BP-5565) (US Patent No. 6,110,714).
- examples of L-glutamic acid-producing bacteria or parent strains for deriving the same also include strains modified to enhance D-xylose-5-phosphate phosphoketolase and / or fructose-6-phosphate phosphoketolase activity. (Special Table 2008-509661). Either one or both of D-xylose-5-phosphate phosphoketolase activity and fructose-6-phosphate phosphoketolase activity may be enhanced. In the present specification, D-xylose-5-phosphate phosphoketolase and fructose-6-phosphate phosphoketolase may be collectively referred to as phosphoketolase.
- D- xylose-5-phosphate - phosphoketolase and active consumes phosphoric acid, to convert xylulose-5-phosphate to glyceraldehyde-3-phosphate and acetyl phosphate, in one molecule H 2 O Means the activity of releasing. This activity is measured by the method described in Goldberg, M. et al. (Methods Enzymol., 9,515-520 (1966)) or L. Meile (J. Bacteriol. (2001) 183; 2929-2936). be able to.
- fructose-6-phosphate phosphoketolase activity means that phosphoric acid is consumed, fructose 6-phosphate is converted into erythrose-4-phosphate and acetyl phosphate, and one molecule of H 2 O is released. Means activity. This activity is measured by the method described in Racker, E (Methods Enzymol., 5, 276-280 (1962)) or L. Meile (J. Bacteriol. (2001) 183; 2929-2936). be able to.
- Examples of the method for imparting or enhancing L-glutamine production ability include a method of modifying a bacterium so that the activity of one or more enzymes selected from L-glutamine biosynthesis enzymes is increased.
- Examples of such an enzyme include, but are not limited to, glutamate dehydrogenase (gdhA) and glutamine synthetase (glnA).
- the method for imparting or enhancing L-glutamine production ability is, for example, selected from an enzyme that catalyzes a reaction that branches from the biosynthetic pathway of L-glutamine to produce a compound other than L-glutamine.
- an enzyme that catalyzes a reaction that branches from the biosynthetic pathway of L-glutamine to produce a compound other than L-glutamine.
- a method of modifying the bacterium so that the activity of the further enzyme is reduced can also be mentioned.
- Such an enzyme is not particularly limited, and includes glutaminase.
- L-glutamine producing bacteria or parent strains for inducing them include strains belonging to the genus Escherichia having a mutant glutamine synthetase in which the tyrosine residue at position 397 of glutamine synthetase is substituted with another amino acid residue. (US Patent Application Publication No. 2003-0148474).
- L-proline producing bacteria examples include a strain in which the activity of one or more enzymes selected from L-proline biosynthesis enzymes are enhanced.
- enzymes involved in L-proline biosynthesis include glutamate 5-kinase, ⁇ -glutamyl-phosphate reductase, and pyrroline-5-carboxylate reductase.
- the proB gene German Patent No. 3127361 encoding glutamate kinase which is desensitized to feedback inhibition by L-proline can be preferably used.
- examples of L-proline-producing bacteria or parent strains for inducing them also include strains in which the activity of an enzyme involved in L-proline degradation is reduced.
- examples of such an enzyme include proline dehydrogenase and ornithine aminotransferase.
- L-proline-producing bacteria or parent strains for deriving them include, but are not limited to, E. coli NRRL B-12403 and NRRL B-12404 (UK Patent No. 2075056), E. coli VKPM B -8012 (Russian patent application 2000124295), E. coli plasmid variant described in German Patent 3127361, Bloom FR et al (The 15th Miami winter symposium, 1983, p.34) Strains belonging to the genus Escherichia such as E. coli 702ilvA (VKPM B-8012) (EP 1172433) capable of producing L-proline without the ilvA gene.
- L-tryptophan producing bacteria L-phenylalanine producing bacteria, L-tyrosine producing bacteria>
- methods for imparting or enhancing L-tryptophan production ability, L-phenylalanine production ability, and / or L-tyrosine production ability include biosynthesis of L-tryptophan, L-phenylalanine, and / or L-tyrosine.
- Biosynthetic enzymes common to these aromatic amino acids are not particularly limited, but 3-deoxy-D-arabinohepturonic acid-7-phosphate synthase (aroG), 3-dehydroquinate synthase (aroB) Shikimate dehydrogenase (aroE), shikimate kinase (aroL), 5-enolic acid pyruvylshikimate 3-phosphate synthase (aroA), chorismate synthase (aroC) (European Patent No. 763127). Expression of genes encoding these enzymes is controlled by a tyrosine repressor (tyrR), and the activity of these enzymes may be enhanced by deleting the tyrR gene (European Patent No. 763127).
- tyrR tyrosine repressor
- L-tryptophan biosynthesis enzyme examples include, but are not limited to, anthranilate synthase (trpE), tryptophan synthase (trpAB), and phosphoglycerate dehydrogenase (serA).
- trpE anthranilate synthase
- trpAB tryptophan synthase
- serA phosphoglycerate dehydrogenase
- L-tryptophan production ability can be imparted or enhanced by introducing DNA containing a tryptophan operon.
- Tryptophan synthase consists of ⁇ and ⁇ subunits encoded by trpA and trpB genes, respectively.
- anthranilate synthase is subject to feedback inhibition by L-tryptophan
- a gene encoding the enzyme into which a mutation that releases feedback inhibition is introduced may be used.
- phosphoglycerate dehydrogenase is feedback-inhibited by L-serine
- a gene encoding the enzyme into which a mutation that releases feedback inhibition is introduced may be used to enhance the activity of the enzyme.
- L-tryptophan-producing ability is imparted or enhanced by increasing the expression of an operon consisting of malate synthase (aceB), isocitrate lyase (aceA), and isocitrate dehydrogenase kinase / phosphatase (aceK). (WO2005 / 103275).
- the L-phenylalanine biosynthetic enzyme is not particularly limited, and examples thereof include chorismate mutase and prefenate dehydratase. Chorismate mutase and prefenate dehydratase are encoded by the pheA gene as a bifunctional enzyme. Since chorismate mutase-prefenate dehydratase is feedback-inhibited by L-phenylalanine, in order to enhance the activity of the enzyme, a gene encoding the enzyme into which a mutation that releases feedback inhibition is introduced may be used.
- the L-tyrosine biosynthetic enzyme is not particularly limited, and examples thereof include chorismate mutase and prephenate dehydrogenase. Chorismate mutase and prefenate dehydrogenase are encoded by the tyrA gene as a bifunctional enzyme. Since chorismate mutase-prefenate dehydrogenase is feedback-inhibited by L-tyrosine, to enhance the activity of the enzyme, a gene encoding the enzyme into which a mutation that releases feedback inhibition is introduced may be used.
- the L-tryptophan, L-phenylalanine, and / or L-tyrosine producing bacterium may be modified so that biosynthesis of aromatic amino acids other than the target aromatic amino acid is lowered.
- L-tryptophan, L-phenylalanine, and / or L-tyrosine-producing bacteria may be modified so that the by-product uptake system is enhanced.
- By-products include aromatic amino acids other than the desired aromatic amino acid. Examples of genes encoding uptake systems of by-products include, for example, uptake systems of tnaB and mtr, which are L-tryptophan uptake systems, and pheP, L-tyrosine, which are genes encoding uptake systems of L-phenylalanine. TyrP, which is a gene coding for (EP1484410).
- E.Ecoli JP4735 carrying a mutant trpS gene encoding a partially inactivated tryptophanyl-tRNA synthetase / pMU3028 (DSM10122) and JP6015 / pMU91 (DSM10123) ⁇ (U.S. Pat.No. 5,756,345)
- E. coli SV164 with trpE allele that encodes anthranilate synthase not subject to feedback inhibition by tryptophan Fos not subject to feedback inhibition by serine E. coli SV164 (pGH5) ⁇
- examples of L-tryptophan-producing bacteria or parent strains for deriving the same also include strains belonging to the genus Escherichia with increased activity of the protein encoded by the yedA gene or the yddG gene (US Patent Application Publication 2003 / 014847348A1). And 2003/0157667 A1).
- L-phenylalanine-producing bacteria or parent strains for deriving them include, but are not limited to, E. coli AJ12739 (tyrA :: Tn10, tyrR, which is deficient in chorismate mutase-prefenate dehydrogenase and tyrosine repressor. ) (VKPM B-8197) (WO03 / 044191), E. coli HW1089 (ATCC 55371) (US Pat. No. 5,354,672) carrying the mutant pheA34 gene encoding chorismate mutase-prefenate dehydratase with desensitized feedback inhibition ), E.
- E. coli MWEC101-b KR8903681
- E. coli NRRL B-12141 E. coli NRRL B-12141
- NRRL B-12145 E. coli NRRL B-12146
- NRRL B-12147 U.S. Pat.No. 4,407,952
- E. coli K-12 [W3110 (tyrA) / TylA) carrying a gene encoding chorismate mutase-prefenate dehydratase whose feedback inhibition is released pPHAB] (FERM BP-3566)
- E. coli K-12 [W3110 (tyrA) / TylA) carrying a gene encoding chorismate mutase-prefenate dehydratase whose feedback inhibition is released pPHAB]
- examples of L-phenylalanine-producing bacteria or parent strains for deriving them also include strains belonging to the genus Escherichia in which the activity of the protein encoded by the yedA gene or the yddG gene is increased (US Patent Application Publication No. 2003/0148473 A1). And 2003/0157667 A1, WO03 / 044192).
- examples of a method for imparting or enhancing L-amino acid-producing ability include a method of modifying a bacterium so that the activity of discharging L-amino acid from the bacterium cell is increased.
- the activity to excrete L-amino acids can be increased, for example, by increasing the expression of a gene encoding a protein that excretes L-amino acids.
- genes encoding proteins that excrete various amino acids include b2682 gene (ygaZ), b2683 gene (ygaH), b1242 gene (ychE), and b3434 gene (yhgN) (Japanese Patent Laid-Open No. 2002-300874) .
- examples of a method for imparting or enhancing L-amino acid producing ability include a method for modifying bacteria so that the activity of a protein involved in sugar metabolism or a protein involved in energy metabolism is increased.
- Proteins involved in sugar metabolism include proteins involved in sugar uptake and glycolytic enzymes.
- genes encoding proteins involved in sugar metabolism include glucose 6-phosphate isomerase gene (pgi; WO 01/02542 pamphlet), phosphoenolpyruvate synthase gene (pps; EP 877090 specification) , Phosphoenolpyruvate carboxylase gene (ppc; WO 95/06114 pamphlet), pyruvate carboxylase gene (pyc; WO 99/18228 pamphlet, European application 1092776), phosphoglucomutase gene (Pgm; WO 03/04598 pamphlet), fructose diphosphate aldolase gene (pfkB, fbp; WO 03/04664 pamphlet), pyruvate kinase gene (pykF; WO 03/008609 pamphlet), transaldolase Gene (talB; WO03 / 008611 pamphlet), fumarase residue Child (
- non-PTS sucrose uptake gene gene csc; European Application Publication No. 149911 pamphlet
- sucrose utilization gene scrAB operon; International Publication No. 90/04636 pamphlet
- genes encoding proteins involved in energy metabolism include a transhydrogenase gene (pntAB; US Pat. No. 5,830,716), a cytochrome bo type oxidase (cyoB; European Patent Application Publication No. 1070376) Is mentioned.
- the gene used for breeding the L-amino acid-producing bacterium is not limited to the gene having the above-described gene information or a gene having a known base sequence unless the function of the encoded protein is impaired. It may be a variant.
- a gene used for breeding an L-amino acid-producing bacterium is an amino acid in which one or several amino acids at one or several positions are substituted, deleted, inserted or added in the amino acid sequence of a known protein. It may be a gene encoding a protein having a sequence.
- the descriptions of lcfA gene and LcfA protein variants described later can be applied mutatis mutandis.
- the bacterium of the present invention has an lcfA gene introduced therein.
- the bacterium of the present invention can be obtained by introducing the lcfA gene into a bacterium belonging to the family Enterobacteriaceae having the ability to produce L-amino acids as described above.
- the bacterium of the present invention can also be obtained by imparting or enhancing L-amino acid-producing ability after introducing the lcfA gene into a bacterium belonging to the family Enterobacteriaceae.
- the bacterium of the present invention may have acquired L-amino acid-producing ability by introducing the lcfA gene.
- the modification for constructing the bacterium of the present invention can be performed in any order.
- the “lcfA gene” refers to a gene that generates a fatty acyl-CoA from a long-chain fatty acid and encodes a protein taken up through the inner membrane.
- the activity of “generating fatty acyl-CoA from a long chain fatty acid and taking it in through the inner membrane” is also referred to as “LcfA activity”.
- LcfA activity can be measured, for example, as long-chain fatty acid uptake activity.
- the long-chain fatty acid uptake activity can be measured, for example, by a known method (Schmelter, T. et al. 2004. J. Biol. Chem. 279: 24163-24170).
- the LcfA activity can also be measured as an activity that catalyzes a reaction for producing fatty acyl-CoA (fatty-acyl-CoA) from a long-chain fatty acid (fatty-acyl-CoA synthetase activity).
- the fatty acyl-CoA synthetase activity can be measured, for example, by a known method (Black, PN. Et al. J Biol Chem. 1992. 267 (35): 25513-20).
- Examples of the lcfA gene include the Bacillus subtilis lcfA gene (J. Biol. Chem. Vol. 282 No. 8 p. 5180-5194).
- the nucleotide sequence of the LcfA gene of Bacillus subtilis and the amino acid sequence of the protein (LcfA protein) encoded by the same gene are shown in SEQ ID NOs: 17 and 18, respectively.
- the lcfA gene may encode a variant of the LcfA protein as long as it has LcfA activity. Such variants may be referred to as “conservative variants”. Examples of conservative variants include homologues and artificially modified forms of the LcfA protein.
- the homolog of the lcfA gene can be easily obtained from a public database by BLAST search or FASTA search using the base sequence of the lcfA gene (SEQ ID NO: 17) as a query sequence, for example.
- the homolog of the lcfA gene can be obtained, for example, by PCR using a bacterial or yeast chromosome as a template and oligonucleotides prepared based on these known gene sequences as primers.
- the gene encoding a conservative variant of LcfA protein may be, for example, the following gene. That is, as long as the lcfA gene encodes a protein having LcfA activity, the lcfA gene represents an amino acid sequence in which one or several amino acids at one or several positions are substituted, deleted, inserted or added in the above amino acid sequence. It may be a gene encoding a protein having the same. In this case, the LcfA activity can usually be maintained at 70% or more, preferably 80% or more, more preferably 90% or more with respect to the protein before one or several substitutions, deletions, insertions or additions. .
- one or several differs depending on the position of the amino acid residue in the three-dimensional structure of the protein and the kind of amino acid residue, but specifically, preferably 1 to 20, more preferably 1 to 10 More preferably, it means 1 to 5, particularly preferably 1 to 3.
- substitution, deletion, insertion, or addition of one or several amino acids described above is a conservative mutation that maintains the protein function normally.
- a typical conservative mutation is a conservative substitution.
- Conservative substitution is a polar amino acid between Phe, Trp, and Tyr when the substitution site is an aromatic amino acid, and between Leu, Ile, and Val when the substitution site is a hydrophobic amino acid. In this case, between Gln and Asn, when it is a basic amino acid, between Lys, Arg, and His, when it is an acidic amino acid, between Asp and Glu, when it is an amino acid having a hydroxyl group Is a mutation that substitutes between Ser and Thr.
- substitutions considered as conservative substitutions include substitution from Ala to Ser or Thr, substitution from Arg to Gln, His or Lys, substitution from Asn to Glu, Gln, Lys, His or Asp, Asp to Asn, Glu or Gln, Cys to Ser or Ala, Gln to Asn, Glu, Lys, His, Asp or Arg, Glu to Gly, Asn, Gln, Lys or Asp Substitution, Gly to Pro substitution, His to Asn, Lys, Gln, Arg or Tyr substitution, Ile to Leu, Met, Val or Phe substitution, Leu to Ile, Met, Val or Phe substitution, Substitution from Lys to Asn, Glu, Gln, His or Arg, substitution from Met to Ile, Leu, Val or Phe, substitution from Phe to Trp, Tyr, Met, Ile or Leu, Ser to Thr or Ala Substitution, substitution from Trp to Phe or Tyr, substitution
- the gene having a conservative mutation as described above is 80% or more, preferably 90% or more, more preferably 95% or more, still more preferably 97% or more, particularly preferably 99%, based on the entire amino acid sequence. It may be a gene encoding a protein having a homology of at least% and having LcfA activity. In the present specification, “homology” may refer to “identity”.
- the lcfA gene is a DNA that encodes a protein having LcfA activity by hybridizing under a stringent condition with a probe that can be prepared from a known gene sequence, for example, a complementary sequence to the whole or a part of the base sequence. May be.
- Stringent conditions refers to conditions under which so-called specific hybrids are formed and non-specific hybrids are not formed.
- highly homologous DNAs for example, 80% or more, preferably 90% or more, more preferably 95% or more, more preferably 97% or more, particularly preferably 99% or more between DNAs having homology.
- the probe used for the hybridization may be a part of a complementary sequence of a gene.
- a probe can be prepared by PCR using an oligonucleotide prepared on the basis of a known gene sequence as a primer and a DNA fragment containing these base sequences as a template.
- hybridization washing conditions include 50 ° C., 2 ⁇ SSC, and 0.1% SDS.
- any codon may be substituted with an equivalent codon.
- the lcfA gene may be modified so as to have an optimal codon according to the codon usage frequency of the host to be used.
- the introduction of the lcfA gene into a bacterium can be performed according to the method for increasing the gene copy number in the “method for increasing protein activity” described later.
- a DNA fragment containing the lcfA gene can be obtained, for example, by PCR using the genomic DNA of a microorganism having the lcfA gene as a template.
- the obtained DNA fragment containing the lcfA gene may be introduced onto a bacterial chromosome, for example.
- the obtained DNA fragment containing the lcfA gene is introduced into the bacterium by, for example, constructing an expression vector for the lcfA gene by ligating with a vector that functions in the host bacterium, and transforming the host bacterium with the expression vector. May be.
- bacteria belonging to the family Enterobacteriaceae may originally have the fadD gene as a gene corresponding to the lcfA gene.
- the bacterium of the present invention may be modified so that the expression of the fadD gene that it originally has is weakened.
- the bacterium of the present invention may be modified to increase the expression of the fadD gene.
- the bacterium of the present invention may be further modified so that the ability to assimilate fatty acids is further increased.
- modifications may include reducing the expression of the fadR gene, enhancing the expression of one or more genes selected from the group consisting of the fadL, fadE, fadD, fadB, and fadA genes, and the cyoABCDE operon. Examples thereof include enhancing expression and combinations thereof (Japanese Patent Laid-Open No. 2011-167071).
- the fadR gene encodes a negative transcription factor for the fad regulon (DiRusso, C. C. et al. 1992. J. Biol. Chem. 267: 8685-8691; DiRusso, C. C. et al. 1993. Mol Microbiol. 7: 311-322).
- the fad regulon includes the fadL, fadE, fadD, fadB, and fadA genes, which encode proteins involved in fatty acid metabolism.
- the fadR gene and fad regulon are found, for example, in bacteria belonging to the family Enterobacteriaceae.
- the fadR gene of Escherichia coli K12 MG1655 strain corresponds to the sequence at positions 124161-1234880 in the genome sequence of the same strain (GenBank accession No. NC_000913).
- the FadR protein of Escherichia coli K12 MG1655 strain is registered under GenBank accession No. NP_415705.
- the fadL gene encodes an outer membrane transporter capable of taking up long-chain fatty acids (Kumar, G. B. and Black, P. N. 1993. J. Biol. Chem. 268: 15469-15476; Stenberg, F. et al. 2005. J. Biol. Chem. 280: 34409-34419).
- the fadL gene of Escherichia coli K12 MG1655 strain corresponds to the sequence from 2459328 to 2460668 in the genome sequence of the same strain (GenBank accession No. NC_000913).
- the FadL protein of Escherichia coli K12 MG1655 strain is registered under GenBank accession No. NP_416846.
- the fadD gene catalyzes the reaction to produce fatty acyl-CoA (fatty-acyl-CoA) from long-chain fatty acids (fatty-acyl-CoA-synthetase activity) and encodes a protein incorporated through the inner membrane ( Dirusso, C. C. and Black, P. N. 2004. J. Biol. Chem. 279: 49563-49566; Schmelter, T. et al. 2004. J. Biol. Chem. 279: 24163-24170).
- the fadD gene of Escherichia coli K12 MG1655 strain corresponds to a complementary sequence of the sequences 160885 to 1887770 in the genome sequence (GenBank ⁇ accession No. NC_000913) of the same strain.
- the FadD protein of Escherichia coli K12 MG1655 strain is registered under GenBank accession No. NP_416319.
- the fadE gene encodes a protein having an acyl-CoA dehydrogenase activity that catalyzes a reaction to oxidize fatty acyl-CoA (O'Brien, W. J. and Frerman, F. E. 1977. J. Bacteriol. 132: 532-540; Campbell, J. W. and Cronan, J. E. 2002. J. Bacteriol. 184: 3759-3764).
- the fadE gene of Escherichia coli K12 MG1655 strain corresponds to a complementary sequence of the sequences from 240859 to 243303 in the genome sequence of the same strain (GenBank accession No. NC_000913).
- the FadE protein of Escherichia coli K12 MG1655 strain is registered under GenBank accession No. NP_414756.
- the fadB gene encodes the ⁇ subunit of the fatty acid oxidation complex.
- the ⁇ subunit includes enoyl-CoA hydratase, 3-hydroxyacyl-CoA dehydrogenase, 3-hydroxyacyl-CoA epimerase, ⁇ 3-cis- ⁇ 2 -Has four activities of trans-enoyl CoA isomerase ( ⁇ 3-cis- ⁇ 2-trans-enoyl-CoA isomerase) (Pramanik, A. et al. 1979. J. Bacteriol. 137: 469-473; Yang, S. Y. and Schulz, H. 1983. J. Biol. Chem. 258: 9780-9785).
- the fadB gene of Escherichia coli K12 MG1655 strain corresponds to the complementary sequence of the 4026805-4028994 position in the genome sequence of the same strain (GenBank accession No. NC_000913).
- the FadB protein of Escherichia coli K12 MG1655 strain is registered under GenBank accession No. NP_418288.
- the fadA gene encodes the ⁇ subunit of the fatty acid oxidation complex.
- the ⁇ subunit has 3-ketoacyl-CoA thiolase activity (Pramanik, A. et al. 1979. J. Bacteriol. 137: 469-473).
- the fadA gene of Escherichia coli K12 MG1655 strain corresponds to a complementary sequence of the 4025632 to 4026795 positions in the genome sequence (GenBank accession No. NC_000913) of the same strain.
- the FadA protein of Escherichia coli K12 MG1655 strain is registered under GenBank accession No. YP_026272.
- the fadA and fadB genes form the fadBA operon (Yang, S. Y. et al. 1990. J. Biol. Chem. 265: 10424-10429).
- the expression of the entire fadBA operon may be enhanced.
- the cyoABCDE operon encodes a cytochrome bo-terminal oxidase complex, which is one of the terminal oxidases.
- cyoB gene has subunit I
- cyoA gene has subunit II
- cyoC gene has subunit III
- cyoC gene has subunit IV
- cyoE gene has heme O synthase activity.
- the cyo operon is found, for example, in bacteria belonging to the family Enterobacteriaceae.
- the cyoABCDE gene of Escherichia coli K12 MG1655 strain is complementary to the sequences of 449887 to 450834, 447874 to 449865, 447270 to 448884, 446941 to 447270, and 446039 to 446929 in the genome sequence (GenBank ⁇ accession No. NC_000913), respectively.
- CyoABCDE protein of Escherichia coli K12 MG1655 strain is registered under GenBank accession No. NP_414966, NP_414965, NP_414964, NP_414963, and NP_414962, respectively.
- the bacterium of the present invention may be modified so that the activity of pyruvate synthase (also referred to as “PS”) and / or pyruvate: NADP + oxidoreductase (also referred to as “PNO”) is increased. (WO2009 / 031565).
- “Pyruvate synthase” refers to an enzyme (EC 1.2.7.1) that reversibly catalyzes the reaction of producing pyruvate from acetyl-CoA and CO 2 using reduced ferredoxin or reduced flavodoxin as an electron donor.
- PS is also referred to as pyruvate oxidoreductase, pyruvate ferredoxin oxidoreductase, or pyruvate flavodoxin oxidoreductase.
- the activity of PS can be measured, for example, according to the method of Yoon et al. (Yoon, K. S. et al. 1997. Arch. Microbiol. 167: 275-279).
- PS-encoding genes include PS genes of bacteria having a reductive TCA cycle such as Chlorobium tepidum, Hydrogenobacter thermophilus, and enterobacteria such as Escherichia coli Autotrophic methane-producing archaea such as PS gene of bacteria belonging to the family, Methanococcus maripaludis, Methanococdocus janaschi (Methanocaldococcus jannaschii), Methanothermobacter thermautotrophicus, etc. methanogens) PS gene.
- enterobacteria such as Escherichia coli Autotrophic methane-producing archaea
- PS gene of bacteria belonging to the family Methanococcus maripaludis
- Methanococdocus janaschi Methanocaldococcus jannaschii
- Methanothermobacter thermautotrophicus etc. methanogens
- Pyruvate: NADP + oxidoreductase refers to an enzyme (EC 1.2.1.15) that reversibly catalyzes the reaction of generating pyruvate from acetyl-CoA and CO 2 using NADPH or NADH as an electron donor. Pyruvate: NADP + oxidoreductase is also referred to as pyruvate dehydrogenase.
- the activity of PNO can be measured, for example, according to the method of Inui et al. (Inui, H. et al. 1987. J. Biol. Chem. 262: 9130-9135).
- PNO gene As a gene encoding PNO (PNO gene), a PNO gene (Nakazawa, M. ⁇ ⁇ ⁇ et al. 2000. FEBS Lett. 479: 155) of Euglena gracilis which is classified as a protozoan in a photosynthetic eukaryotic microorganism. -156; GenBank Accession No. AB021127), PNO gene of the protozoan Cryptosporidium parvum (Rotte, C. et al. 2001. Mol. Biol. Evol. 18: 710-720), diatom Talasiosila pseudonana (Tharassiosira pseudonana) PNO homologous gene (Ctrnacta, V. et al. 2006. J. Eukaryot. Microbiol. 53: 225-231).
- Enhancement of PS activity can be achieved by improving the supply of electron donors required for PS activity in addition to the method for increasing protein activity as described later.
- PS activity can be enhanced by enhancing the activity of recycling ferredoxin or flavodoxin oxidized form to reduced form, enhancing the biosynthetic ability of ferredoxin or flavodoxin, or a combination thereof (WO2009 / 031565 ).
- ferredoxin-NADP + reductase examples include ferredoxin-NADP + reductase.
- Feredoxin-NADP + reductase refers to an enzyme (EC 1.18.1.2) that reversibly catalyzes a reaction of converting ferredoxin or an oxidized form of flavodoxin into a reduced form using NADPH as an electron donor.
- Ferredoxin-NADP + reductase is also referred to as flavodoxin-NADP + reductase.
- the activity of ferredoxin-NADP + reductase can be measured, for example, according to the method of Blaschkowski et al. (Blaschkowski, H. P. et al. 1982. Eur. J. Biochem. 123: 563-569).
- ferredoxin-NADP + reductase The genes encoding ferredoxin-NADP + reductase (ferredoxin-NADP + reductase gene) include the fpr gene of Escherichia coli, the ferredoxin-NADP + reductase gene of Corynebacterium glutamicum, and NADPH- of Pseedomonas putida. And putidaredoxin reductase gene (Koga, H. et al. 1989. J. Biochem. (Tokyo) 106: 831-836).
- ferredoxin or flavodoxin can be enhanced by enhancing the expression of a gene encoding ferredoxin (ferredoxin gene) or a gene encoding flavodoxin (flavodoxin gene).
- the ferredoxin gene or flavodoxin gene is not particularly limited as long as it encodes ferredoxin or flavodoxin that can be used by PS and an electron donor regeneration system.
- ferredoxin gene examples include Escherichia coli fdx gene and yfhL gene, corynebacterium glutamicum fer gene, bacteria ferredoxin gene having a reductive TCA cycle such as Chlorobium tepidum and Hydrogenobacter thermophilus.
- flavodoxin gene examples include Escherichia coli fldA gene and fldB gene, and bacterial flavodoxin gene having a reductive TCA cycle.
- the above genes for example, fadR gene, fad regulon, cyoABCDE operon, PS gene, PNO gene, ferredoxin-NADP + reductase gene, ferredoxin gene, flavodoxin gene are as described above unless the function of the encoded protein is impaired.
- the gene is not limited to a gene having genetic information and a gene having a known base sequence, and may be a variant thereof.
- the gene is a gene encoding a protein having an amino acid sequence in which one or several amino acids at one or several positions are substituted, deleted, inserted or added in the amino acid sequence of a known protein. May be.
- gene and protein variants the above descriptions concerning the lcfA gene and LcfA protein variants can be applied mutatis mutandis.
- Protein activity increases “means that the activity per cell of the protein is increased relative to unmodified strains such as wild strains and parental strains. Note that “increasing protein activity” is also referred to as “enhancing protein activity”. “Protein activity increases” specifically means that the number of molecules per cell of the protein is increased and / or the function per molecule of the protein compared to an unmodified strain. Is increasing. That is, “activity” in the case of “increasing protein activity” means not only the catalytic activity of the protein, but also the transcription amount (mRNA amount) or translation amount (protein amount) of the gene encoding the protein. May be. The activity of the protein is not particularly limited as long as it is increased compared to the non-modified strain.
- the protein activity is increased 1.5 times or more, 2 times or more, or 3 times or more compared to the non-modified strain.
- “the protein activity increases” means not only to increase the activity of the protein in a strain that originally has the activity of the target protein, but also to the activity of the protein in a strain that does not originally have the activity of the target protein. Including granting.
- a suitable protein may be introduced after weakening and / or deleting the activity of the target protein originally possessed by the bacterium.
- Modification that increases the activity of the protein is achieved, for example, by increasing the expression of the gene encoding the protein.
- increasing gene expression is also referred to as “enhanced gene expression”.
- the expression of the gene may be increased 1.5 times or more, 2 times or more, or 3 times or more, for example, as compared to the unmodified strain.
- increasing gene expression means not only increasing the expression level of a target gene in a strain that originally expresses the target gene, but also in a strain that originally does not express the target gene. Including expressing a gene. That is, “increasing gene expression” includes, for example, introducing the gene into a strain that does not hold the target gene and expressing the gene.
- An increase in gene expression can be achieved, for example, by increasing the copy number of the gene.
- Increase in gene copy number can be achieved by introducing the gene into the chromosome of the host microorganism.
- Introduction of a gene into a chromosome can be performed, for example, using homologous recombination (Miller I, J. H. Experiments in Molecular Genetics, 1972, Cold Spring Harbor Laboratory). Only one copy of the gene may be introduced, or two copies or more may be introduced.
- multiple copies of a gene can be introduced into a chromosome by performing homologous recombination with a sequence having multiple copies on the chromosome as a target. Examples of sequences having many copies on a chromosome include repetitive DNA sequences (inverted DNA) and inverted repeats present at both ends of a transposon.
- homologous recombination may be performed by targeting an appropriate sequence on a chromosome such as a gene unnecessary for L-amino acid production.
- Homologous recombination is, for example, the Red-driven integration method (Datsenko, K. A, and Wanner, B. L. Proc. Natl. Acad. Sci. U S A. 97: 6640-6645 (2000) ), A method using a linear DNA, a method using a plasmid containing a temperature-sensitive replication origin, a method using a plasmid capable of conjugation transfer, a method using a suicide vector that does not have a replication origin and functions in a host, or a phage It can be performed by the transduction method used.
- the gene can also be randomly introduced onto the chromosome using transposon or Mini-Mu (Japanese Patent Laid-Open No. 2-109985, US Pat. No. 5,882,888, EP805867B1).
- the increase in the copy number of the gene can also be achieved by introducing a vector containing the target gene into the host bacterium.
- a DNA fragment containing a target gene is linked to a vector that functions in the host bacterium to construct an expression vector for the gene, and the host bacterium is transformed with the expression vector to increase the copy number of the gene.
- a DNA fragment containing a target gene can be obtained, for example, by PCR using a genomic DNA of a microorganism having the target gene as a template.
- a vector capable of autonomous replication in a host bacterial cell can be used.
- the vector is preferably a multicopy vector.
- the vector preferably has a marker such as an antibiotic resistance gene.
- the vector may be, for example, a vector derived from a bacterial plasmid, a vector derived from a yeast plasmid, a vector derived from a bacteriophage, a cosmid, or a phagemid.
- vectors capable of autonomous replication in Escherichia coli cells include pUC19, pUC18, pHSG299, pHSG399, pHSG398, pACYC184, pBR322, pSTV29 (all available from Takara Bio Inc.), pMW219 (Nippon Gene) ), PTrc99A (Pharmacia), pPROK vector (Clontech), pKK233-2 (Clontech), pET vector (Novagen), pQE vector (Qiagen), and wide host range vector RSF1010.
- the gene may be retained in the bacterium of the present invention so that it can be expressed.
- the gene may be introduced so as to be expressed under the control of a promoter sequence that functions in the bacterium of the present invention.
- the promoter may be a host-derived promoter or a heterologous promoter.
- the promoter may be a native promoter of a gene to be introduced or a promoter of another gene. As the promoter, for example, a stronger promoter as described later may be used.
- the gene to be introduced is not particularly limited as long as it encodes a protein that functions in the host.
- the introduced gene may be a host-derived gene or a heterologous gene.
- each gene when two or more genes are introduced, each gene may be retained in the bacterium of the present invention so that it can be expressed.
- all the genes may be held on a single expression vector, or all may be held on a chromosome.
- each gene may be separately hold
- an operon may be constructed by introducing two or more genes.
- the increase in gene expression can be achieved by improving the transcription efficiency of the gene.
- Improvement of gene transcription efficiency can be achieved, for example, by replacing a promoter of a gene on a chromosome with a stronger promoter.
- strong promoter is meant a promoter that improves transcription of the gene over the native wild-type promoter. Examples of stronger promoters include the known high expression promoters T7 promoter, trp promoter, lac promoter, tac promoter, and PL promoter.
- a highly active promoter of a conventional promoter may be obtained by using various reporter genes.
- the promoter activity can be increased by bringing the -35 and -10 regions in the promoter region closer to the consensus sequence (WO 00/18935).
- the highly active promoter include various tac-like promoters (Katashkina JI et al. Russian Patent application 2006134574) and pnlp8 promoter (WO2010 / 027045). Methods for evaluating promoter strength and examples of strong promoters are described in Goldstein et al. (Prokaryotickpromoters in biotechnology. Biotechnol. Annu. Rev.,. 1, 105-128 (1995)).
- the increase in gene expression can be achieved by improving the translation efficiency of the gene.
- Improvement of gene translation efficiency can be achieved, for example, by replacing the Shine-Dalgarno (SD) sequence (also referred to as ribosome binding site (RBS)) of the gene on the chromosome with a stronger SD sequence.
- SD Shine-Dalgarno
- RBS ribosome binding site
- a stronger SD sequence is meant an SD sequence in which the translation of mRNA is improved over the originally existing wild-type SD sequence.
- RBS of gene 10 derived from phage T7 can be mentioned (Olins P. O. et al, Gene, 1988, 73, 227-235).
- substitution of several nucleotides in the spacer region between the RBS and the start codon, particularly the sequence immediately upstream of the start codon (5'-UTR), or insertion or deletion contributes to mRNA stability and translation efficiency. It is known to have a great influence, and the translation efficiency of a gene can be improved by modifying them.
- a site that affects gene expression such as a promoter, an SD sequence, and a spacer region between the RBS and the start codon is also collectively referred to as an “expression control region”.
- the expression regulatory region can be determined using a promoter search vector or gene analysis software such as GENETYX.
- GENETYX gene analysis software
- These expression control regions can be modified by, for example, a method using a temperature sensitive vector or a Red driven integration method (WO2005 / 010175).
- Improvement of gene translation efficiency can also be achieved, for example, by codon modification.
- codon modification when performing heterologous expression of a gene, the translation efficiency of the gene can be improved by replacing rare codons present in the gene with synonymous codons that are used more frequently. Codon substitution can be performed, for example, by a site-specific mutagenesis method in which a target mutation is introduced into a target site of DNA. Alternatively, gene fragments in which codons have been replaced may be fully synthesized. The frequency of codon usage in various organisms can be found in the “Codon Usage Database” (http://www.kazusa.or.jp/codon; Nakamura, Y. et al, Nucl. Acids Res., 28, 292 (2000)) Is disclosed.
- the increase in gene expression can be achieved by amplifying a regulator that increases gene expression or by deleting or weakening a regulator that decreases gene expression.
- the modification that increases the enzyme activity can be achieved, for example, by enhancing the specific activity of the enzyme.
- Enzymes with enhanced specific activity can be obtained by searching for various organisms, for example.
- a highly active type may be obtained by introducing a mutation into a conventional enzyme.
- the enhancement of specific activity may be used alone or in any combination with the above-described method for enhancing gene expression.
- the method of transformation is not particularly limited, and a conventionally known method can be used.
- recipient cells are treated with calcium chloride to increase DNA permeability (Mandel, M. and Higa, A., J. Mol. Biol. 1970, 53, 159-162) and methods for introducing competent cells from proliferating cells and introducing DNA as reported for Bacillus subtilis (Duncan, C. H., Wilson, G. A. and Young, F. E .., 1997. Gene 1: 153-167) can be used.
- DNA-receptive cells such as those known for Bacillus subtilis, actinomycetes, and yeast, can be made into protoplasts or spheroplasts that readily incorporate recombinant DNA into recombinant DNA.
- Introduction method (Chang, S. and Choen, SN, 1979. Mol. Gen. Genet. 168: 111-115; Bibb, M. J., Ward, J. M. and Hopwood, O. A. 1978. Nature 274: 398-400; Hinnen, A., Hicks, J. B. and Fink, G. R. 1978. Proc. Natl.Acad. Sci. USA 75: 1929-1933) can also be applied.
- the increase in protein activity can be confirmed by measuring the activity of the protein.
- the increase in protein activity can also be confirmed by confirming that the expression of the gene encoding the protein has increased.
- An increase in gene expression can be confirmed by confirming that the transcription amount of the gene has increased, or by confirming that the amount of protein expressed from the gene has increased.
- the transcription amount of the gene has increased by comparing the amount of mRNA transcribed from the gene with an unmodified strain such as a wild strain or a parent strain.
- Methods for assessing the amount of mRNA include Northern hybridization, RT-PCR, etc. (Sambrook, J., et al., Molecular Cloning A Laboratory Manual / Third Edition, Cold spring Harbor Laboratory Press, Cold spring Harbor (USA ), 2001).
- the amount of mRNA may be increased by, for example, 1.5 times or more, 2 times or more, or 3 times or more, compared to the unmodified strain.
- the amount of protein can be increased by, for example, 1.5 times or more, 2 times or more, or 3 times or more as compared to the unmodified strain.
- the above-described techniques for increasing the activity of the protein include enhancing the activity of any protein, such as an L-amino acid biosynthetic enzyme or transporter, or any gene, such as any of these It can be used to enhance the expression of protein-encoding genes, fad regulon, cyoABCDE operon, PS gene and PNO gene.
- any protein such as an L-amino acid biosynthetic enzyme or transporter
- any gene such as any of these It can be used to enhance the expression of protein-encoding genes, fad regulon, cyoABCDE operon, PS gene and PNO gene.
- Protein activity decreases means that the activity per cell of the protein is decreased compared to wild-type strains and parental unmodified strains, and the activity is completely lost. including. Specifically, “the activity of the protein is decreased” means that the number of molecules per cell of the protein is decreased and / or the function per molecule of the protein compared to the unmodified strain. Means that it is decreasing. In other words, “activity” in the case of “decrease in protein activity” means not only the catalytic activity of the protein but also the transcription amount (mRNA amount) or translation amount (protein amount) of the gene encoding the protein. May be. Note that “the number of molecules per cell of the protein is decreased” includes a case where the protein does not exist at all.
- the function per molecule of the protein is reduced includes the case where the function per molecule of the protein is completely lost.
- the activity of the protein is not particularly limited as long as it is lower than that of the non-modified strain. For example, it is 50% or less, 20% or less, 10% or less, 5% or less, or 0, compared to the non-modified strain. %.
- the modification that reduces the activity of the protein is achieved, for example, by reducing the expression of a gene encoding the protein.
- Gene expression decreases includes the case where the gene is not expressed at all.
- the expression of the gene is reduced is also referred to as “the expression of the gene is weakened”. Gene expression may be reduced to, for example, 50% or less, 20% or less, 10% or less, 5% or less, or 0% compared to an unmodified strain.
- the decrease in gene expression may be due to, for example, a decrease in transcription efficiency, a decrease in translation efficiency, or a combination thereof.
- Reduction of gene expression can be achieved, for example, by modifying an expression regulatory sequence such as a gene promoter or Shine-Dalgarno (SD) sequence.
- the expression control sequence is preferably modified by 1 base or more, more preferably 2 bases or more, particularly preferably 3 bases or more. Further, part or all of the expression regulatory sequence may be deleted.
- reduction of gene expression can be achieved, for example, by manipulating factors involved in expression control. Factors involved in expression control include small molecules (such as inducers and inhibitors) involved in transcription and translation control, proteins (such as transcription factors), nucleic acids (such as siRNA), and the like.
- the modification that decreases the activity of the protein can be achieved, for example, by destroying a gene encoding the protein.
- Gene disruption can be achieved, for example, by deleting part or all of the coding region of the gene on the chromosome.
- the entire gene including the sequences before and after the gene on the chromosome may be deleted.
- the region to be deleted may be any region such as an N-terminal region, an internal region, or a C-terminal region as long as a decrease in protein activity can be achieved.
- the longer region to be deleted can surely inactivate the gene.
- it is preferable that the reading frames of the sequences before and after the region to be deleted do not match.
- gene disruption is, for example, introducing an amino acid substitution (missense mutation) into a coding region of a gene on a chromosome, introducing a stop codon (nonsense mutation), or adding or deleting 1 to 2 bases. It can also be achieved by introducing a frameshift mutation (Journal of Biological Chemistry 272: 8611-8617 (1997) Proceedings of the National Academy of Sciences, USA 95 5511-5515 (1998), Journal of Biological Chemistry 26 116, 20833 -20839 (1991)).
- gene disruption can be achieved, for example, by inserting another sequence into the coding region of the gene on the chromosome.
- the insertion site may be any region of the gene, but the longer the inserted sequence, the more reliably the gene can be inactivated.
- Other sequences are not particularly limited as long as they reduce or eliminate the activity of the encoded protein, and examples include marker genes such as antibiotic resistance genes and genes useful for heterologous protein production.
- Modifying a gene on a chromosome as described above includes, for example, deleting a partial sequence of the gene and preparing a deleted gene modified so as not to produce a normally functioning protein.
- transforming bacteria with recombinant DNA containing, and causing homologous recombination between the deleted gene and the wild-type gene on the chromosome to replace the wild-type gene on the chromosome with the deleted gene Can be achieved.
- the recombinant DNA can be easily manipulated by including a marker gene in accordance with a trait such as auxotrophy of the host. Even if the protein encoded by the deletion-type gene is produced, it has a three-dimensional structure different from that of the wild-type protein, and its function is reduced or lost.
- the modification that reduces the activity of the protein may be performed by, for example, a mutation treatment.
- Mutation treatment includes X-ray irradiation or ultraviolet irradiation, or N-methyl-N′-nitro-N-nitrosoguanidine (MNNG), ethyl methanesulfonate (EMS), methylmethanesulfonate (MMS), etc.
- MNNG N-methyl-N′-nitro-N-nitrosoguanidine
- EMS ethyl methanesulfonate
- MMS methylmethanesulfonate
- the decrease in the activity of the protein can be confirmed by measuring the activity of the protein.
- the decrease in protein activity can also be confirmed by confirming that the expression of the gene encoding the protein has decreased.
- the decrease in gene expression can be confirmed by confirming that the transcription amount of the gene has decreased, or confirming that the amount of protein expressed from the gene has decreased.
- the amount of transcription of the gene has been reduced by comparing the amount of mRNA transcribed from the same gene with that of the unmodified strain.
- methods for evaluating the amount of mRNA include Northern hybridization, RT-PCR, and the like (Molecular cloning (Cold spring spring Laboratory Laboratory, Cold spring Harbor (USA), 2001)).
- the amount of mRNA may be reduced to, for example, 50% or less, 20% or less, 10% or less, 5% or less, or 0% compared to the unmodified strain.
- the amount of protein may be reduced to, for example, 50% or less, 20% or less, 10% or less, 5% or less, or 0% compared to the unmodified strain.
- the gene has been destroyed by determining part or all of the nucleotide sequence, restriction enzyme map, full length, etc. of the gene according to the means used for the destruction.
- the above-described method for reducing the activity of a protein can be performed by any protein, for example, an enzyme or L-amino acid that catalyzes a reaction that produces a compound other than the target L-amino acid by branching from the biosynthetic pathway of the target L-amino acid. It can be used to reduce the activity of a biosynthetic enzyme repressor, and to reduce the expression of any gene, for example, the gene encoding these arbitrary proteins or the fadR gene.
- the method of the present invention comprises culturing the bacterium of the present invention in a medium containing a fatty acid, and collecting L-amino acid from the medium. It is a manufacturing method of an amino acid. That is, in the method of the present invention, L-amino acid can be produced by fermentation using fatty acid as a carbon source.
- “Fatty acid” means a monovalent carboxylic acid of a long-chain hydrocarbon represented by the general formula C n H m COOH (where n + 1 and m + 1 represent the number of carbon atoms and the number of hydrogen atoms contained in the fatty acid, respectively). Says acid. There are various types of fatty acids having different carbon numbers and unsaturation levels. In general, fatty acids having 12 or more carbon atoms are often referred to as long-chain fatty acids. Moreover, it is known that a fatty acid is a structural component of fats and oils, and the composition of the fatty acid which comprises fats and oils changes with kinds of fats and oils.
- the fatty acid is not particularly limited as long as the bacterium of the present invention can be used as a carbon source.
- the fatty acid include lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, and linoleic acid.
- fatty acids selected from lauric acid, myristic acid, palmitic acid, stearic acid, and oleic acid are preferable because they are easily used by the bacterium of the present invention.
- Lauric acid (C 11 H 23 COOH) is a saturated fatty acid having 12 carbon atoms and is contained in coconut oil and palm oil.
- Myristic acid (C 13 H 27 COOH) is a saturated fatty acid having 14 carbon atoms and is contained in palm oil and palm oil. Palmitic acid (C 15 H 31 COOH) is a saturated fatty acid having 16 carbon atoms, and is generally abundant in vegetable oils. Stearic acid (C 17 H 35 COOH) is a saturated fatty acid having 18 carbon atoms, and is abundant in animal fats and vegetable oils. Oleic acid (C 17 H 33 COOH) is a monovalent unsaturated fatty acid having 18 carbon atoms, and is abundant in animal fats and vegetable oils.
- Linoleic acid (C 17 H 31 COOH) is a polyunsaturated fatty acid having 18 carbon atoms containing cis-type double bonds at the 9th and 12th positions, and is abundant in vegetable oils such as safflower oil and corn oil. .
- the fatty acid one kind of fatty acid may be used, or two or more kinds of fatty acids may be used in combination. When two or more fatty acids are used in combination, the ratio of each fatty acid is not particularly limited as long as the bacterium of the present invention can use the fatty acid as a carbon source.
- fatty acid a pure fatty acid such as a purified fatty acid may be used, or a mixture containing a fatty acid and a component other than the fatty acid may be used. Examples of such a mixture include a hydrolyzate of fats and oils.
- Oils and fats are esters of fatty acids and glycerol and are also called triglycerides.
- the fats and oils are not particularly limited as long as the fats and oils contain fatty acids that can be used as a carbon source by the bacterium of the present invention and can be hydrolyzed.
- the fats and oils preferably contain fatty acids that can be used as a carbon source by the bacterium of the present invention as a constituent component in a high ratio.
- As fats and oils those in any form such as fatty oil (oil) indicating liquid at normal temperature and fat (fat) indicating solid at normal temperature may be used.
- fatty oil (oil) indicating liquid at normal temperature
- fat (fat) indicating solid at normal temperature
- fats and oils 1 type of fats and oils may be used, and 2 or more types of fats and oils may be used in combination.
- fats and oils pure fats and oils, such as refined fats and oils, may be used, and a mixture containing fats and oils and components other than fats and oils may be used.
- the plant extract containing fats and oils, the fraction containing fats and oils, for example, an oil cake, are mentioned.
- Oil lees are mainly produced from the deoxidation process for removing free fatty acids in the vegetable oil refining process, and are a by-product of the vegetable oil production process, generally containing 40 to 70% moisture, Contains 20-50% fats and oils.
- crude glycerol produced in the production process of biodiesel may contain several percent of fatty acid methyl ester or free fatty acid that is biodiesel, which can be fractionated for use.
- animal fats include butter, pork fat, beef tallow, sheep fat, whale oil, sardine oil, and herring oil.
- vegetable oils include palm oil, olive oil, rapeseed oil, soybean oil, rice bran oil, walnut oil, sesame oil, and peanut oil. Palm oil is an oil and fat that can be obtained from the fruit of oil palm, and its production volume has increased in recent years due to the increasing use of biodiesel fuel.
- Oil palm (oil palm) is a general term for plants classified into the genus Elaeis. Crude palm oil (crude palm oil) generally refers to unrefined palm oil produced in an oil mill and is traded as crude palm oil.
- microalgae that accumulate fats and oils are known (Chisti, Y. 2007. Biotechnol Adv. 25: 294-306), and it is also possible to extract and use fats and oils from the algal bodies.
- algal bodies contain organic substances such as saccharides, proteins, and amino acids. However, a mixture containing these may be hydrolyzed and used as a carbon source.
- the hydrolyzate of fats and oils is obtained by hydrolyzing fats and oils.
- Hydrolysis may be performed, for example, chemically or enzymatically.
- Industrially for example, a continuous high-temperature hydrolysis method is generally performed in which oil and fat are in countercurrent contact with water under high temperature (250-260 ° C.) and high pressure (5-6 MPa).
- the hydrolysis reaction is carried out at low temperatures (around 30 ° C) using enzymes (Jaeger, K. E. et al. 1994. FEMS Microbiol. Rev. 15: 29-63) .
- an enzyme lipase that catalyzes the hydrolysis reaction of fats and oils can be used.
- Lipase is an industrially important enzyme and has various industrial uses (Hasan, F. et al. 2006. Enzyme and Microbiol. Technol. 39: 235-251).
- the hydrolyzate of fats and oils is obtained as a mixture containing a fatty acid and glycerol. It is known that the weight ratio of glycerol to fatty acid is about 10% in a general fat and oil hydrolyzate such as palm oil.
- the hydrolyzate of fats and oils is not particularly limited as long as it contains a fatty acid.
- the hydrolyzate of fats and oils may be used as it is, or may be used after adding or removing desired components.
- a mixture of fatty acids obtained by removing glycerol from a hydrolyzate of fats and oils may be used as the carbon source.
- a desired fatty acid may be obtained from a hydrolyzate of fats and oils and used as a carbon source.
- the fatty acid may be a free form or a salt thereof, or a mixture thereof.
- the salt include alkali metal salts such as sodium salt and potassium salt.
- Alkali metal salts of fatty acids are highly water-soluble, and are micellized and retained in water, so that they can be efficiently used by the bacteria of the present invention.
- fatty acids it is preferable to increase the solubility of fatty acids by performing a treatment for promoting homogenization of fatty acids so that the bacterium of the present invention can use fatty acids more efficiently.
- Examples of the treatment for promoting homogenization include emulsification.
- Emulsification can be carried out, for example, by adding an emulsification accelerator or a surfactant.
- Examples of the emulsification accelerator include phospholipids and sterols.
- As the surfactant for example, a surfactant generally used in the field of biology can be used.
- nonionic surfactants include, for example, polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monooleate (Tween 80), alkyl glucosides such as n-octyl ⁇ -D-glucoside, Sucrose fatty acid esters such as sugar stearate, polyglycerin fatty acid esters such as polyglycerol stearate, Triton X-100 (TritonTriX-100), polyoxyethylene (20) cetyl ether (Brij-58), nonylphenol ethoxy Rate (Tergitol NP-40).
- the surfactant include zwitterionic surfactants such as alkylbetaines such as N, N-dimethyl-N-dodecylglycine betaine.
- examples of the treatment for promoting homogenization include homogenizer treatment, homomixer treatment, ultrasonic treatment, high pressure treatment, and high temperature treatment.
- homogenizer treatment and / or ultrasonic treatment are preferable.
- the treatment for promoting homogenization is preferably performed under alkaline conditions in which fatty acids can exist stably.
- the alkaline condition is preferably pH 9 or more, more preferably pH 10 or more.
- the fatty acid may or may not be used as the sole carbon source. That is, in the method of the present invention, other carbon sources may be used in combination with the fatty acid.
- Other carbon sources are not particularly limited, but include sugars such as glucose, fructose, sucrose, lactose, galactose, xylose, arabinose, molasses, starch hydrolyzate, hydrolyzate of biomass, fumaric acid, citric acid, succinate
- sugars such as glucose, fructose, sucrose, lactose, galactose, xylose, arabinose, molasses
- starch hydrolyzate hydrolyzate of biomass
- fumaric acid citric acid
- succinate examples thereof include organic acids such as acids, and alcohols such as ethanol, glycerol, and crude glycerol.
- the ratio of fatty acids in the total carbon source may be, for example, 10% by weight or more, preferably 30% by weight or more, more preferably 50% by weight or more.
- the ratio of fatty acid to the total amount of fatty acid and glucose is, for example, 2.5% by weight, 5% by weight, 10% by weight, 15% by weight, and 20% by weight. You may select suitably according to the raw material to be used.
- one type of carbon source may be used, or two or more types of carbon sources may be used in combination.
- components in addition to the carbon source, other components can be appropriately used as the medium component.
- components other than the carbon source include a nitrogen source, a sulfur source, a phosphate source, and a growth promoting factor (a component having a growth promoting effect).
- Nitrogen sources include ammonia, ammonium salts, nitrates, and urea.
- ammonium salts include ammonium sulfate, ammonium carbonate, ammonium chloride, ammonium phosphate, and ammonium acetate.
- Ammonia gas and ammonia water used for pH adjustment can also be used as a nitrogen source.
- the nitrogen source also include organic nitrogen sources such as peptone, yeast extract, meat extract, malt extract, corn steep liquor, and soybean hydrolysate. As the nitrogen source, one kind of nitrogen source may be used, or two or more kinds of nitrogen sources may be used in combination.
- the phosphoric acid source examples include phosphates such as potassium dihydrogen phosphate and dipotassium hydrogen phosphate, and phosphate polymers such as pyrophosphoric acid.
- phosphates such as potassium dihydrogen phosphate and dipotassium hydrogen phosphate
- phosphate polymers such as pyrophosphoric acid.
- the phosphoric acid source one type of phosphoric acid source may be used, or two or more types of phosphoric acid sources may be used in combination.
- sulfur source examples include inorganic sulfur compounds such as sulfate, thiosulfate, and sulfite, and sulfur-containing amino acids such as cysteine, cystine, and glutathione. Of these, ammonium sulfate is preferred.
- the sulfur source one kind of sulfur source may be used, or two or more kinds of sulfur sources may be used in combination.
- Examples of the growth promoting factor include trace metals, amino acids, vitamins, nucleic acids, peptone containing these, casamino acid, yeast extract, and soybean protein degradation product.
- Examples of trace metals include iron, manganese, magnesium, and calcium.
- Vitamins include vitamin B1, vitamin B2, vitamin B6, nicotinic acid, nicotinamide, and vitamin B12.
- As the growth promoting factor one kind of growth promoting factor may be used, or two or more kinds of growth promoting factors may be used in combination.
- L-lysine producing bacteria often have an enhanced L-lysine biosynthetic pathway and weakened L-lysine resolution. Therefore, when culturing such L-lysine-producing bacteria, for example, one or more components selected from L-threonine, L-homoserine, L-isoleucine, and L-methionine are supplemented to the medium. Is preferred.
- Culture conditions are not particularly limited as long as the bacterium of the present invention can grow and the target L-amino acid is produced.
- the culture can be performed, for example, under normal conditions used for culture of bacteria such as Escherichia coli.
- the culture conditions may be appropriately set according to various conditions such as the type of bacteria used and the type of L-amino acid to be produced.
- Culture can be performed by batch culture, fed-batch culture, continuous culture, or a combination thereof.
- the culture medium at the start of the culture is also referred to as “initial culture medium”.
- a medium supplied to a culture system (fermentor) in fed-batch culture or continuous culture is also referred to as “fed-batch medium”.
- feeding-batch medium supplying a feeding medium to a culture system in fed-batch culture or continuous culture is also referred to as “fed-batch”.
- each medium component for example, a carbon source such as a fatty acid, a nitrogen source, a sulfur source, a phosphate source, and a growth promoting factor may be contained in the initial medium, the fed-batch medium, or both.
- the type of component contained in the initial culture medium may or may not be the same as the type of component contained in the fed-batch medium.
- concentration of each component contained in a starting culture medium may be the same as the density
- the fatty acid concentration in the medium is not particularly limited as long as the bacterium of the present invention can use the fatty acid as a carbon source.
- the fatty acid concentration in the medium may be, for example, 10 w / v% or less, preferably 5 w / v% or less, more preferably 2 w / v% or less.
- the fatty acid concentration in the medium may be, for example, 0.2 w / v% or more, preferably 0.5 w / v% or more, more preferably 1.0 w / v% or more.
- the fatty acid may be contained in the initial culture medium, the feed medium, or both in the concentration range exemplified above.
- the fatty acid when fatty acid is contained in the fed-batch medium, the fatty acid has a fatty acid concentration in the medium after feeding of, for example, 5 w / v% or less, preferably 2 w / v% or less, more preferably 1 w / v%. It may be contained in a fed-batch medium so that Further, when fatty acid is contained in the fed-batch medium, the fatty acid has a fatty acid concentration in the medium after feeding of, for example, 0.01 w / v% or more, preferably 0.02 w / v% or more, more preferably You may contain in a feeding medium so that it may become 0.05 w / v% or more.
- Fatty acid may be contained in the concentration range exemplified above when used only as a carbon source. Moreover, when using another carbon source together, a fatty acid may be contained in the concentration range illustrated above. In addition, when other carbon sources are used in combination, the fatty acid may be contained in a concentration range in which the above exemplified concentration range is appropriately modified, for example, according to the ratio of fatty acids in the total carbon source.
- the fatty acid may or may not be contained in the medium in a certain concentration range throughout the culture.
- the fatty acid may be insufficient for a certain period. “Insufficient” means that the required amount is not satisfied.
- the concentration in the medium may be zero.
- the “certain period” may be, for example, a period of 10% or less, a period of 20% or less, or a period of 30% or less of the entire culture period. It is preferable that other carbon sources are satisfied during the period of shortage of fatty acids.
- the fatty acid is insufficient for a certain period, it is included in “culturing bacteria in a medium containing fatty acid” as long as there is a culture period in a medium containing fatty acid.
- the fatty acid concentration is determined by gas chromatography (Hashimoto, K. et al. 1996. Biosci. Biotechnol. Biochem. 70: 22-30) or HPLC (Lin, J. T. et al. 1998. J. Chromatogr. A. 808: 43-49).
- the culture can be performed aerobically, for example.
- the culture can be performed by aeration culture or shaking culture.
- the oxygen concentration may be controlled to be, for example, about 5 to 50%, preferably about 10% of the saturated oxygen concentration.
- the temperature may be controlled, for example, at 20 to 45 ° C., preferably 33 to 42 ° C.
- the pH may be controlled, for example, 5-9.
- calcium carbonate can be added in advance, or the culture can be neutralized with an alkali such as ammonia gas or aqueous ammonia. Under such conditions, for example, by culturing for about 10 to 120 hours, a significant amount of L-amino acid is accumulated in the culture solution.
- the culture of bacteria may be performed separately for seed culture and main culture.
- the culture conditions of the seed culture and the main culture may or may not be the same.
- both seed culture and main culture may be performed by batch culture.
- seed culture may be performed by batch culture, and main culture may be performed by fed-batch culture or continuous culture.
- fed-batch culture or continuous culture fed-batch may be continued throughout the entire culture period or only during a part of the culture period.
- multiple feedings may be performed intermittently.
- the duration of each feeding is, for example, 30% or less, preferably 20% or less, more preferably 10% of the total time of the plurality of feedings.
- the start and stop of fed batch may be repeated so that:
- the second and subsequent feedings are controlled so that they are started when the carbon source in the fermentation medium is depleted in the immediately preceding feeding stop phase.
- Carbon source depletion can be detected, for example, by increasing pH or increasing dissolved oxygen concentration.
- extraction of the culture solution may be continued throughout the entire culture period, or may be continued only during a part of the culture period. Further, in continuous culture, a plurality of culture solutions may be extracted intermittently. Extraction and feeding of the culture solution may or may not be performed simultaneously. For example, the feeding may be performed after the culture solution is extracted, or the culture solution may be extracted after the feeding.
- the amount of the culture solution to be withdrawn is preferably the same as the amount of the medium to be fed.
- the “same amount” may be, for example, an amount of 93 to 107% with respect to the amount of medium to be fed.
- the withdrawal may be started within 5 hours, preferably within 3 hours, more preferably within 1 hour after the start of fed-batch.
- the bacterial cells can be reused by recovering L-amino acid from the extracted culture medium and recirculating the filtration residue containing the bacterial cells in the fermenter (French Patent No. 2669935). ).
- a method for producing a basic amino acid such as L-lysine there is known a method for fermenting and producing a basic amino acid using bicarbonate ion and / or carbonate ion as a main counter ion of the basic amino acid. (Unexamined-Japanese-Patent No. 2002-65287, US2002-0025564A, EP1813677A).
- the pH of the medium during the culture is controlled to 6.5 to 9.0, preferably 6.5 to 8.0, and the pH of the medium at the end of the culture is controlled to 7.2 to 9.0.
- the pressure in the fermenter during the fermentation is controlled to be positive, and the carbon dioxide gas is cultured. It is preferred to feed the liquid or both.
- the supply air pressure may be set higher than the exhaust pressure.
- the carbon dioxide gas generated by fermentation dissolves in the culture solution to produce bicarbonate ions and / or carbonate ions, and the bicarbonate ions and / or carbonate ions are counter ions of basic amino acids.
- the fermenter pressure is 0.03 to 0.2 MPa, preferably 0.05 to 0.15 MPa, more preferably 0.1 to 0.3 MPa in terms of gauge pressure (differential pressure relative to atmospheric pressure). Is mentioned.
- Fermenter pressure, carbon dioxide supply, and limited air supply can be determined, for example, by measuring the pH of the medium, the concentration of bicarbonate and / or carbonate ions in the medium, or the concentration of ammonia in the medium. Can be determined.
- sulfate ions and / or chloride ions are used as counter ions for basic amino acids, so a sufficient amount of ammonium sulfate and / or ammonium chloride, or sulfate such as protein as a nutrient component Degradation products and / or hydrochloric acid degradation products were added to the medium. Therefore, a large amount of sulfate ion and / or chloride ion was present in the medium, and the weakly acidic carbonate ion concentration was extremely low, on the order of ppm.
- one of the purposes is to reduce the amount of sulfate ions and / or chloride ions used, so the total molar concentration of sulfate ions and chloride ions contained in the medium is usually 700 mM or less, preferably 500 mM or less, more preferably 300 mM or less, further preferably 200 mM or less, particularly preferably 100 mM or less.
- the concentration of sulfate ions and / or chloride ions bicarbonate ions and / or carbonate ions can be more easily present in the medium. That is, in this method, compared to the conventional method, it is possible to keep the pH of the medium for making the amount of bicarbonate ions and / or carbonate ions necessary for counter ions of basic amino acids present in the medium low. Become.
- the concentration of bicarbonate ions and / or anions other than carbonate ions (also referred to as other anions) in the medium only needs to include an amount necessary for the growth of basic amino acid-producing bacteria. Preferably, it is low.
- other anions include chloride ions, sulfate ions, phosphate ions, ionized organic acids, and hydroxide ions.
- the total molar concentration of other anions contained in the medium is usually 900 mM or less, preferably 700 mM or less, more preferably 500 mM or less, still more preferably 300 mM or less, and particularly preferably 200 mM or less.
- ammonium sulfate or the like is fed to the medium at the beginning of the culture, and the feed is stopped during the culture. Or you may feed ammonium sulfate etc., maintaining the balance with the dissolved amount of the carbonate ion and / or bicarbonate ion in a culture medium.
- ammonia may be fed to the medium as a nitrogen source for basic amino acids.
- pH is controlled with ammonia
- ammonia supplied to increase the pH can be used as a nitrogen source for basic amino acids.
- Ammonia can be supplied to the medium alone or with other gases.
- the total ammonia concentration in the medium is preferably controlled to a concentration that does not inhibit the production of basic amino acids.
- the total ammonia concentration that “does not inhibit the production of basic amino acids” is, for example, preferably 50% or more, more preferably compared to the yield and / or productivity in the case of producing basic amino acids under optimum conditions. Examples include a total ammonia concentration that provides a yield and / or productivity of 70% or more, particularly preferably 90% or more.
- the total ammonia concentration in the medium is preferably a concentration of 300 mM or less, more preferably 250 mM, particularly preferably 200 mM or less. The degree of ammonia dissociation decreases with increasing pH.
- Undissociated ammonia is more toxic to bacteria than ammonium ions. Therefore, the upper limit of the total ammonia concentration also depends on the pH of the culture solution. That is, the higher the pH of the culture solution, the lower the allowable total ammonia concentration. Therefore, the total ammonia concentration that does not inhibit the production of basic amino acids is preferably set for each pH. However, the total ammonia concentration range allowed at the highest pH during the culture may be used as the total ammonia concentration range throughout the culture period.
- the total ammonia concentration as a nitrogen source necessary for the growth of basic amino acid-producing bacteria and the production of basic amino acids does not continue to be a state where ammonia is depleted during the culture, and the microorganism is due to a shortage of nitrogen source.
- the productivity of the target substance is not reduced by the above, it is not particularly limited and can be set appropriately.
- the ammonia concentration may be measured over time during the culture, and a small amount of ammonia may be added to the medium when the ammonia in the medium is depleted.
- the ammonia concentration when ammonia is added is not particularly limited.
- the total ammonia concentration is preferably 1 mM or more, more preferably 10 mM or more, and particularly preferably 20 mM or more.
- the medium may contain cations other than basic amino acids.
- cations other than basic amino acids include K, Na, Mg, and Ca derived from medium components.
- the total molar concentration of cations other than basic amino acids is preferably 50% or less of the molar concentration of total cations.
- L-amino acids from the fermentation broth is usually performed by ion exchange resin method (Nagai, H. et al., Separation Science and Technology, 39 (16), 3691-3710), precipitation method, membrane separation method 9-164323, Japanese Patent Laid-Open No. 9-173792), crystallization methods (WO2008 / 078448, WO2008 / 078646), and other known methods can be combined.
- ion exchange resin method Naagai, H. et al., Separation Science and Technology, 39 (16), 3691-3710
- precipitation method precipitation method
- membrane separation method 9-164323 Japanese Patent Laid-Open No. 9-173792
- crystallization methods WO2008 / 078448, WO2008 / 078646
- other known methods can be combined.
- L-amino acid accumulates in the microbial cells, for example, the microbial cells are crushed with ultrasonic waves, and the microbial cells are removed by centrifugation from the supernatant
- the recovered L-amino acid may contain bacterial cells, medium components, moisture, and bacterial metabolic byproducts in addition to the L-amino acid.
- the purity of the collected L-amino acid is, for example, 50% or more, preferably 85% or more, particularly preferably 95% or more (JP1214636B, USP 5,431,933, 4,956,471, 4,777,051, 4946654, 5,840,358, 6,238,714, US2005 / 0025878)) .
- L-amino acid is precipitated in the medium, it can be recovered by centrifugation or filtration.
- the L-amino acid precipitated in the medium may be isolated together after crystallization of the L-amino acid dissolved in the medium.
- Example 1 Construction of Escherichia coli L-lysine production strain into which fadLDEBA gene group has been introduced ⁇ 1-1> Outline of construction of fadLDEBA gene group introduction strain In this example, from fadL, fadD, fadE, fadB, and fadA An Escherichia coli L-lysine production strain into which the gene group described above was introduced was constructed. This gene group encodes enzymes in the ⁇ -oxidation pathway of fatty acids (Clark, DP and Cronan Jr., JE 1996. p. 343-357.
- FadB and fadA form an operon composed of fadBA.
- the Escherichia coli L-lysine producing strain WC196 ⁇ cadA ⁇ ldcC (AJ110692: hereinafter this strain is also referred to as WC196LC) described in International Patent Publication WO2006 / 078039 was used.
- This strain is a strain in which the cadA gene and the ldcC gene are disrupted in the WC196 strain (FERM BP-5252).
- the gene group was introduced by constructing the fadEBA operon and fadLD operon by PCR and inserting them on the chromosome of WC196LC.
- the fadEBA operon and fadLD operon were first developed in a method called “Red-driven integration”, first developed by Datsenko and Wanner (Datsenko, K. A. and Wanner, B. L. 2000. Proc. ⁇ ⁇ Natl. Acad. Sci USA. 97: 6640-6645) was inserted into the chromosome of Escherichia coli K-12 MG1655 strain. Subsequently, the fadEBA operon and the fadLD operon were inserted on the chromosome of WC196LC by P1 transduction using the obtained strain as a donor.
- the antibiotic resistance gene incorporated into the constructed strain was extracted from the ⁇ phage-derived excision system (Cho, E. H., Gumport, R. I., and Gardner, J. F. 2002. J. Bacteriol. 184 : 5200-5203). The specific construction procedure is shown below.
- fadEBA operon-introduced strain As a fadEBA operon sequence, a DNA fragment (att-cat) linking a lambda phage attachment site and a chloramphenicol resistance gene upstream of the fadE gene and a tac promoter sequence (Ptac) A DNA fragment having an att-cat-Ptac fragment ligated with (Gene 25 (2-3) 167-178 (1983)) and having a fadBA gene downstream of the fadE gene was constructed. The att-cat-Ptac fragment can be constructed with reference to pMW118-attL-Cm-attR (WO2005 / 010175).
- PCR was performed using the chromosomal DNA of Escherichia coli K-12 MG1655 as a template using the primers shown in SEQ ID NOs: 1 and 2, and an atd-cat-Ptac fragment and a fadE fragment linked to the fadBA gene were obtained. Obtained. Furthermore, PCR was performed using the primers shown in SEQ ID NOs: 3 and 4 using the att-cat-Ptac fragment as a template to obtain an att-cat-Ptac fragment linked to the 5 ′ side of the fadE fragment.
- PCR was carried out using the primers shown in SEQ ID NOs: 5 and 6 using the chromosomal DNA of Escherichia coli K-12 MG1655 as a template to obtain a fadBA fragment linked to the 3 ′ side of the fadE fragment.
- These three PCR products were purified and ligated to the vector pMW119 digested with BamHI using In-Fusion Advantage PCR PCR Cloning Kit (Clontech) to construct plasmid pMW-att-cat-PtacfadEBA for fadEBA operon sequence amplification .
- PCR was performed using the plasmid pMW-att-cat-PtacfadEBA as a template using the primers shown in SEQ ID NOs: 7 and 8, and the fadEBA operon was genomically located at the site of the yciQ gene, an unknown function gene of Escherichia coli K-12KMG1655 strain.
- the att-cat-PtacfadEBA fragment for introduction above was obtained.
- the obtained att-cat-PtacfadEBA fragment was inserted into the yciQ gene site of Escherichia coli K-12 MG1655 strain by the red-driven integration method.
- Candidate strains with the desired gene replacement were selected using chloramphenicol resistance as an index. It was confirmed by PCR that the target gene replacement occurred in the candidate strain.
- the obtained fadEBA operon-introduced strain was named MG1655 ⁇ yciQ :: att-cat-PtacfadEBA.
- MG1655 ⁇ yciQ :: att-cat-PtacfadEBA was obtained.
- P1 transduction was performed on the WC196LC strain, and a strain in which the fadEBA operon was inserted at the site of the yciQ gene on the chromosome of the WC196LC strain was constructed.
- Candidate strains with the desired gene replacement were selected using chloramphenicol resistance as an index. It was confirmed by PCR that the target gene replacement occurred in the candidate strain.
- the obtained fadEBA operon-introduced strain was named WC196LC ⁇ yciQ :: att-cat-PtacfadEBA.
- pMW-intxis-ts Japanese Patent Laid-Open No. 2005-058227
- pMW-intxis-ts is a plasmid carrying a gene encoding lambda phage integrase (Int) and a gene encoding excisionase (Xis) and having temperature-sensitive replication ability.
- a WC196LC ⁇ yciQ :: att-cat-PtacfadEBA strain competent cell obtained above was prepared according to a conventional method, transformed with the helper plasmid pMW-intxis-ts, and LB containing 100 mg / L ampicillin at 30 ° C. Plated on an agar medium, ampicillin resistant strains were selected. Next, in order to remove the pMW-intxis-ts plasmid, it was subcultured on LB agar medium at 42 ° C., and the resulting colonies were tested for ampicillin resistance and chloramphenicol resistance. Att-cat and pMW -Acquired stocks where intxis-ts is missing. This strain was named WC196LCPtacfadEBA strain.
- the fadLD operon sequence has a tac promoter sequence upstream of the fadL gene and a ribosome binding site (RBS) ⁇ (Gene 73 (1988) 227-235) derived from the upstream sequence of the T7 phage 10 gene, and the T7 phage 10 downstream of the fadL gene.
- RBS ribosome binding site
- PCR using Escherichia coli K-12 ⁇ MG1655 chromosomal DNA as a template using the primers shown in SEQ ID NOs: 9 and 10 was performed to obtain the atd-cat-Ptac fragment and the fadL fragment linked to the fadD gene. It was. Further, PCR was performed using the primers shown in SEQ ID NOs: 11 and 12 and the att-cat-Ptac fragment as a template to obtain an att-cat-Ptac fragment linked to the 5 ′ side of the fadL fragment.
- PCR was carried out using the primers shown in SEQ ID NOs: 13 and 14 using the chromosomal DNA of Escherichia coli K-12 MG1655 as a template to obtain a fadD fragment linked to the 3 ′ side of the fadL fragment.
- the start codon sequence of fadD was ttg in the chromosomal DNA sequence of Escherichia coli K-12 MG1655 strain, but it was replaced with atg.
- PCR was performed using the plasmid pMW-att-cat-PtacfadLD as a template using the primers shown in SEQ ID NOs: 15 and 16, and the genome of the fadLD operon at the site of the yegD gene, a function-unknown gene of Escherichia coli K-12655MG1655 strain
- the att-cat-PtacfadLD fragment for introduction above was obtained.
- the obtained att-cat-PtacfadLD fragment was inserted into the yegD gene site of Escherichia coli K-12 MG1655 strain by the red-driven integration method.
- Candidate strains with the desired gene replacement were selected using chloramphenicol resistance as an index. It was confirmed by PCR that the target gene replacement occurred in the candidate strain.
- the obtained fadLD operon-introduced strain was named MG1655 ⁇ yegD :: att-cat-PtacfadLD.
- WC196LCPtacfadEBA strain was subjected to P1 transduction, and a strain in which the fadLD operon was inserted into the yegD gene site on the chromosome of WC196LCPtacfadEBA strain was constructed.
- Candidate strains with the desired gene replacement were selected using chloramphenicol resistance as an index. It was confirmed by PCR that the target gene replacement occurred in the candidate strain.
- the obtained fadLD operon-introduced strain was named WC196LCPtacfadEBA ⁇ yegD :: att-cat-PtacfadLD.
- the WC196LCPtacfadEBA ⁇ yegD :: att-cat-PtacfadLD strain competent cell obtained above was prepared according to a conventional method, and transformed with the helper plasmid pMW-intxis-ts. Plated on LB agar medium containing 100 mg / L ampicillin at 30 ° C. to select ampicillin resistant strains. Next, in order to remove the pMW-intxis-ts plasmid, it was subcultured on LB agar medium at 42 ° C., and the resulting colonies were tested for ampicillin resistance and chloramphenicol resistance. Att-cat and pMW -Acquired stocks where intxis-ts is missing. This strain was named WC196LCPtacfadEBAPtacfadLD strain.
- the obtained WC196LCPtacfadEBAPtacfadLD / pCABD2 strain was cultured at 37 ° C. in an LB medium containing 20 ⁇ g / L streptomycin until the OD600 was about 0.3.
- an equal volume of 40% glycerol solution and the culture solution were added and stirred, and then dispensed in appropriate amounts and stored at ⁇ 80 ° C. to obtain a glycerol stock.
- Example 2 Construction of Escherichia coli L-lysine producing bacterium introduced with lcfA gene and fadLEBA gene group ⁇ 2-1> Outline of construction of lcfA gene and fadLEBA gene group introduction strain lcfA as a fadD gene derived from Bacillus subtilis A gene (J. Biol. Chem. Vol. 282 No. 8 p. 5180-5194) has been reported. The complete nucleotide sequence of the Bacillus subtilis chromosome has already been clarified (Nature 390: 249-56 (1997)), and the nucleotide sequence of the lcfA gene has been reported in this document.
- SEQ ID NO: 17 shows the nucleotide sequence of the lcfA gene
- SEQ ID NO: 18 shows the amino acid sequence encoded by the lcfA gene.
- the fadLlcfA operon was constructed based on the base sequence of the lcfA gene and inserted into the chromosome of the MG1655 strain by the Red-driven integration method. Subsequently, the fadLlcfA operon was inserted on the chromosome of WC196LCPtacfadEBA by P1 transduction using the MG1655 strain into which the fadLlcfA operon was inserted as a donor. Furthermore, the antibiotic resistance gene integrated into the constructed strain was removed by a ⁇ phage-derived excision system. The specific construction procedure is shown below.
- a fadLlcfA operon sequence As a fadLlcfA operon sequence, a tac promoter sequence upstream of the fadL gene and a ribosome binding site (RBS) derived from a T7 phage 10 gene upstream sequence (Gene 73 (1988) 227 -235) and a DNA fragment having a ribosome binding site (RBS) derived from the upstream sequence of the T7 phage 10 gene and the lcfA gene downstream of the fadL gene.
- RBS ribosome binding site
- PCR using Escherichia coli K-12 MG1655 chromosomal DNA as a template using the primers shown in SEQ ID NOs: 19 and 20 was performed to obtain an atd-cat-Ptac fragment and a fadL fragment linked to the lcfA gene. It was. Furthermore, PCR was performed using the primers shown in SEQ ID NOs: 21 and 22 and the att-cat-Ptac fragment as a template to obtain an att-cat-Ptac fragment linked to the 5 ′ side of the fadL fragment.
- PCR was performed using the primers shown in SEQ ID NOs: 23 and 24 using the chromosomal DNA of Bacillus subtilis 168M as a template to obtain an lcfA fragment linked to the 3 ′ side of the fadL fragment.
- These three PCR products were purified and ligated to BamHI-digested vector pMW119 using In-Fusion Advantage PCR PCR Cloning Kit (Clontech) to construct plasmid pMW-att-cat-PtacfadLlcfA for fadLlcfA operon sequence amplification .
- PCR was performed using the plasmid pMW-att-cat-PtacfadLlcfA as a template using the primers shown in SEQ ID NOs: 25 and 26, and the genome of the fadLlcfA operon at the site of the yegD gene, a function-unknown gene of Escherichia coli K-121MG1655 strain
- the att-cat-PtacfadLlcfA fragment for introduction above was obtained.
- the obtained att-cat-PtacfadLlcfA fragment was inserted into the yegD gene site of Escherichia coli K-12 MG1655 strain by the red-driven integration method.
- Candidate strains with the desired gene replacement were selected using chloramphenicol resistance as an index. It was confirmed by PCR that the target gene replacement occurred in the candidate strain.
- the obtained fadLlcfA operon-introduced strain was named MG1655 ⁇ yegD :: att-cat-PtacfadLlcfA.
- MG1655 ⁇ yegD att-cat-PtacfadLlcfA as a donor
- P1 transduction was performed on the WC196LCPtacfadEBA strain, and a strain in which the fadLlcfA operon was inserted at the site of the yegD gene on the chromosome of the WC196LCPtacfadEBA strain was constructed.
- Candidate strains with the desired gene replacement were selected using chloramphenicol resistance as an index. It was confirmed by PCR that the target gene replacement occurred in the candidate strain.
- the obtained fadLlcfA operon-introduced strain was named WC196LCPtacfadEBA ⁇ yegD :: att-cat-PtacfadLlcfA.
- the WC196LCPtacfadEBA ⁇ yegD :: att-cat-PtacfadLlcfA strain competent cell obtained above was prepared according to a conventional method, and transformed with the helper plasmid pMW-intxis-ts. Plated on LB agar medium containing 100 mg / L ampicillin at 30 ° C. to select ampicillin resistant strains. Next, in order to remove the pMW-intxis-ts plasmid, it was subcultured on LB agar medium at 42 ° C., and the resulting colonies were tested for ampicillin resistance and chloramphenicol resistance. Att-cat and pMW -Acquired stocks where intxis-ts is missing. This strain was named WC196LCPtacfadEBAPtacfadLlcfA strain.
- the obtained WC196LCPtacfadEBAPtacfadLlcfA / pCABD2 strain was cultured at 37 ° C. in an LB medium containing 20 mg / L of streptomycin until the OD600 reached about 0.3. Next, an equal volume of 40% glycerol solution and the culture solution were added and stirred, and then dispensed in appropriate amounts and stored at ⁇ 80 ° C. to obtain a glycerol stock.
- Example 3 L-lysine production by lcfA gene and fadLEBA gene group-introduced strains Melt glycerol stock of WC196LCPtacfadEBAPtacfadLlcfA / pCABD2 strain, WC196LCPtacfadEBAPtacfadLfadD / pCABD2 strain, and control strain WC196LC / pCABD2 strain (WO2006 / 078039) was uniformly applied to an LB agar medium plate containing 20 mg / L of streptomycin and cultured at 37 ° C. for 24 hours.
- the amount of L-lysine in the culture supernatant was measured with a biosensor BF-5 (Oji Scientific Instruments).
- the degree of growth was measured by turbidity (OD600) after the medium was diluted with a Tween 0.5% solution.
- Table 1 shows the average results when glucose 30 g / L and sodium oleate 4 g / L are used as the carbon source.Table 1 shows the average results when glucose 20 g / L and sodium oleate 3 g / L is used as the carbon source. It shows in Table 2.
- the L-lysine producing strain (WC196LCPtacfadEBAPtacfadLlcfA / pCABD2) introduced with the lcfA gene and the fadLEBA gene group is the control strain (WC196LC / pCABD2) and the L-lysine producing strain (WC196LCPtacfadEBAPtacfadLfaD introduced with the fadLDEBA gene group.
- WC196LCPtacfadEBAPtacfadLfaD introduced with the fadLDEBA gene group.
- L-lysine production was significantly higher.
- L-amino acid-producing ability of bacteria when fatty acids are used as a carbon source can be improved, and L-amino acids can be efficiently produced using fatty acids as a carbon source.
- SEQ ID NOs: 1, 2 PCR primers for amplification of fadE gene fragments
- SEQ ID NOs: 3, 4 PCR primers for amplification of att-cat-Ptac fragments
- SEQ ID NOs: 5 6: PCR primers for amplification of fadBA gene fragments
- SEQ ID NOs: 7, 8 att- PCR primer for cat-PtacfadEBA gene fragment amplification
- 10 PCR primer for amplification of fadL gene fragment
- 12 PCR primer for amplification of att-cat-Ptac fragment
- 14 PCR for amplification of fadD gene fragment
- Primer SEQ ID NOs: 15 and 16 PCR primers for amplification of att-cat-PtacfadLfadD gene fragment
- SEQ ID NO: 17 Base sequence of lcfA gene of Bacillus subtilis
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Abstract
Description
[1]
L-アミノ酸の製造方法であって、
L-アミノ酸生産能を有する腸内細菌科に属する細菌を、脂肪酸を含有する培地中で培養すること、および該培地からL-アミノ酸を採取すること、を含み、
前記細菌が、lcfA遺伝子が導入された細菌であり、
前記lcfA遺伝子が、下記(A)~(D)からなる群より選択されるDNAである、方法:
(A)配列番号18に示すアミノ酸配列を含むタンパク質をコードするDNA;
(B)配列番号18に示すアミノ酸配列において、1若しくは数個のアミノ酸の置換、欠失、挿入、又は付加を含むアミノ酸配列を含み、かつ、長鎖脂肪酸から脂肪酸アシルCoAを生成するとともに、内膜を通して取り込む活性を有するタンパク質をコードするDNA;
(C)配列番号17に示す塩基配列を含むDNA;
(D)配列番号17に示す塩基配列に相補的な塩基配列又は該塩基配列から調製され得るプローブとストリンジェントな条件下でハイブリダイズし、かつ、長鎖脂肪酸から脂肪酸アシルCoAを生成するとともに、内膜を通して取り込む活性を有するタンパク質をコードするDNA。
[2]
前記細菌が、さらに、脂肪酸資化能が高まるように改変されている、前記方法。
[3]
下記(a)~(d)のいずれかにより脂肪酸資化能が高まるように改変された、前記方法。
(a)fadR遺伝子の発現を弱化させること;
(b)fadL、fadE、fadD、fadB、及びfadA遺伝子からなる群より選択される1またはそれ以上の遺伝子の発現を増強させること;
(c)cyoABCDEオペロンの発現の発現を増強させること;
(d)それらの組み合わせ。
[4]
前記脂肪酸がオレイン酸である、前記方法。
[5]
前記培地が、さらに、脂肪酸以外の炭素源を含有する、前記方法。
[6]
前記脂肪酸以外の炭素源がグルコースである、前記方法。
[7]
前記L-アミノ酸がL-リジンである、前記方法。
[8]
前記細菌がエシェリヒア属細菌である、前記方法。
[9]
前記細菌がエシェリヒア・コリである、前記方法。
本発明の方法に用いられる細菌(以下、「本発明の細菌」ともいう)は、L-アミノ酸生産能を有する腸内細菌科に属する細菌であって、且つ、lcfA遺伝子が導入された細菌である。本発明の細菌は、脂肪酸を炭素源として利用する能力を有する。
本発明において、「L-アミノ酸生産能を有する細菌」とは、脂肪酸を含有する培地で培養したときに、目的とするL-アミノ酸を生成し、回収できる程度に培地中または菌体内に蓄積する能力を有する細菌をいう。L-アミノ酸生産能を有する細菌は、非改変株よりも多い量の目的とするL-アミノ酸を培地に蓄積することができる細菌であってよい。非改変株としては、野生株や親株が挙げられる。また、L-アミノ酸生産能を有する細菌は、好ましくは0.5g/L以上、より好ましくは1.0g/L以上の量の目的とするL-アミノ酸を培地に蓄積することができる細菌であってもよい。
L-リジン生産菌又はそれを誘導するための親株としては、L-リジン生合成系酵素から選択される1またはそれ以上の酵素の活性が増強された株が挙げられる。そのような酵素としては、特に制限されないが、ジヒドロジピコリン酸シンターゼ(dihydrodipicolinate synthase)(dapA)、アスパルトキナーゼIII(aspartokinase III)(lysC)、ジヒドロジピコリン酸レダクターゼ(dihydrodipicolinate reductase)(dapB)、ジアミノピメリン酸デカルボキシラーゼ(diaminopimelate decarboxylase)(lysA)、ジアミノピメリン酸デヒドロゲナーゼ(diaminopimelate dehydrogenase)(ddh)(米国特許第6,040,160号)、ホスホエノールピルビン酸カルボキシラーゼ(phosphoenolpyrvate carboxylase)(ppc)、アスパラギン酸セミアルデヒドデヒドロゲナーゼ(aspartate semialdehyde dehydrogenease)(asd)、アスパラギン酸アミノトランスフェラーゼ(aspartate aminotransferase)(アスパラギン酸トランスアミナーゼ(aspartate transaminase))(aspC)、ジアミノピメリン酸エピメラーゼ(diaminopimelate epimerase)(dapF)、テトラヒドロジピコリン酸スクシニラーゼ(tetrahydrodipicolinate succinylase)(dapD)、スクシニルジアミノピメリン酸デアシラーゼ(succinyl-diaminopimelate deacylase)(dapE)及びアスパルターゼ(aspartase)(aspA)(EP 1253195 A)が挙げられる。なお、カッコ内は、その遺伝子の略記号である(以下の記載においても同様)。これらの酵素の中では、ジヒドロジピコリン酸レダクターゼ、ジアミノピメリン酸デカルボキシラーゼ、ジアミノピメリン酸デヒドロゲナーゼ、ホスホエノールピルビン酸カルボキシラーゼ、アスパラギン酸アミノトランスフェラーゼ、ジアミノピメリン酸エピメラーゼ、アスパラギン酸セミアルデヒドデヒドロゲナーゼ、テトラヒドロジピコリン酸スクシニラーゼ、及びスクシニルジアミノピメリン酸デアシラーゼから選択される1またはそれ以上の酵素の活性を増強するのが好ましい。また、L-リジン生産菌又はそれを誘導するための親株では、エネルギー効率に関与する遺伝子(cyo)(EP 1170376 A)、ニコチンアミドヌクレオチドトランスヒドロゲナーゼ(nicotinamide nucleotide transhydrogenase)をコードする遺伝子(pntAB)(米国特許第5,830,716号)、ybjE遺伝子(WO2005/073390)、またはこれらの組み合わせの発現レベルが増大していてもよい。アスパルトキナーゼIII(lysC)はL-リジンによるフィードバック阻害を受けるので、同酵素の活性を増強するには、L-リジンによるフィードバック阻害が解除されたアスパルトキナーゼIIIをコードする変異型lysC遺伝子を利用してもよい(米国特許5,932,453号明細書)。また、ジヒドロジピコリン酸合成酵素(dapA)L-リジンによるフィードバック阻害を受けるので、同酵素の活性を増強するには、L-リジンによるフィードバック阻害が解除されたジヒドロジピコリン酸合成酵素をコードする変異型dapA遺伝子を利用してもよい。
L-スレオニン生産菌又はそれを誘導するための親株としては、L-スレオニン生合成系酵素から選択される1またはそれ以上の酵素の活性が増強された株が挙げられる。そのような酵素としては、特に制限されないが、アスパルトキナーゼIII(lysC)、アスパラギン酸セミアルデヒドデヒドロゲナーゼ(asd)、アスパルトキナーゼI(thrA)、ホモセリンキナーゼ(homoserine kinase)(thrB)、スレオニンシンターゼ(threonine synthase)(thrC)、アスパラギン酸アミノトランスフェラーゼ(アスパラギン酸トランスアミナーゼ)(aspC)が挙げられる。これらの酵素の中では、アスパルトキナーゼIII、アスパラギン酸セミアルデヒドデヒドロゲナーゼ、アスパルトキナーゼI、ホモセリンキナーゼ、アスパラギン酸アミノトランスフェラーゼ、及びスレオニンシンターゼから選択される1またはそれ以上の酵素の活性を増強するのが好ましい。L-スレオニン生合成系遺伝子は、スレオニン分解が抑制された株に導入してもよい。スレオニン分解が抑制された株としては、例えば、スレオニンデヒドロゲナーゼ活性が欠損したE. coli TDH6株(特開2001-346578号)が挙げられる。
L-アルギニン生産菌又はそれを誘導するための親株としては、L-アルギニン生合成系酵素から選択される1またはそれ以上の酵素の活性が増強された株が挙げられる。そのような酵素としては、特に制限されないが、N-アセチルグルタミルフォスフェートレダクターゼ(argC)、オルニチンアセチルトランスフェラーゼ(argJ)、N-アセチルグルタメートキナーゼ(argB)、アセチルオルニチントランスアミナーゼ(argD)、オルニチンカルバモイルトランスフェラーゼ(argF)、アルギノコハク酸シンテターゼ(argG)、アルギノコハク酸リアーゼ(argH)、カルバモイルフォスフェートシンテターゼ(carAB)が挙げられる。N-アセチルグルタミン酸シンターゼ(argA)遺伝子としては、例えば、野生型の15位~19位に相当するアミノ酸残基が置換され、L-アルギニンによるフィードバック阻害が解除された変異型N-アセチルグルタミン酸シンターゼをコードする遺伝子を用いると好適である(欧州出願公開1170361号明細書)。
L-シトルリンおよびL-オルニチンは、L-アルギニンと生合成経路が共通している。よって、N-アセチルグルタミン酸シンターゼ(argA)、N-アセチルグルタミルリン酸レダクターゼ(argC)、オルニチンアセチルトランスフェラーゼ(argJ)、N-アセチルグルタミン酸キナーゼ(argB)、アセチルオルニチントランスアミナーゼ(argD)、および/またはアセチルオルニチンデアセチラーゼ(argE)の酵素活性を上昇させることによって、L-シトルリンおよび/またはL-オルニチンの生産能を付与または増強することができる(国際公開2006-35831号パンフレット)。
L-ヒスチジン生産菌又はそれを誘導するための親株としては、L-ヒスチジン生合成系酵素から選択される1またはそれ以上の酵素の活性が増強された株が挙げられる。そのような酵素としては、特に制限されないが、ATPホスホリボシルトランスフェラーゼ(hisG)、ホスホリボシルAMPサイクロヒドロラーゼ(hisI)、ホスホリボシル-ATPピロホスホヒドロラーゼ(hisI)、ホスホリボシルフォルミミノ-5-アミノイミダゾールカルボキサミドリボタイドイソメラーゼ(hisA)、アミドトランスフェラーゼ(hisH)、ヒスチジノールフォスフェイトアミノトランスフェラーゼ(hisC)、ヒスチジノールフォスファターゼ(hisB)、ヒスチジノールデヒドロゲナーゼ(hisD)が挙げられる。
L-システイン生産能を付与又は増強するための方法としては、例えば、L-システイン生合成系酵素から選択される1またはそれ以上の酵素の活性が増大するように細菌を改変する方法が挙げられる。そのような酵素としては、特に制限されないが、セリンアセチルトランスフェラーゼや3-ホスホグリセリン酸デヒドロゲナーゼが挙げられる。セリンアセチルトランスフェラーゼ活性は、例えば、システインによるフィードバック阻害に耐性の変異型セリンアセチルトランスフェラーゼをコードする変異型cysE遺伝子を細菌に導入することにより増強できる。変異型セリンアセチルトランスフェラーゼは、例えば、特開平11-155571や米国特許公開第20050112731に開示されている。また、3-ホスホグリセリン酸デヒドロゲナーゼ活性は、例えば、セリンによるフィードバック阻害に耐性の変異型3-ホスホグリセリン酸デヒドロゲナーゼをコードする変異型serA遺伝子を細菌に導入することにより増強できる。変異型3-ホスホグリセリン酸デヒドロゲナーゼは、例えば、米国特許第6,180,373号に開示されている。
また、L-メチオニン生産菌又はそれを誘導するための親株として、具体的には、特に制限されないが、L-スレオニン要求株や、ノルロイシンに耐性を有する変異株が挙げられる(特開2000-139471号)。また、L-メチオニン生産菌又はそれを誘導するための親株としては、L-メチオニンによるフィードバック阻害に対して耐性をもつ変異型ホモセリントランスサクシニラーゼを保持する株も挙げられる(特開2000-139471、US20090029424)。なお、L-メチオニンはL-システインを中間体として生合成されるため、L-システインの生産能の向上によりL-メチオニンの生産能も向上させることができる(特開2000-139471、US20080311632)。
L-ロイシン生産菌又はそれを誘導するための親株としては、L-ロイシン生合成系酵素から選択される1またはそれ以上の酵素の活性が増強された株が挙げられる。そのような酵素としては、特に制限されないが、leuABCDオペロンの遺伝子にコードされる酵素が挙げられる。また、酵素活性の増強には、例えば、L-ロイシンによるフィードバック阻害が解除されたイソプロピルマレートシンターゼをコードする変異leuA遺伝子(米国特許第6,403,342号)が好適に利用できる。
L-イソロイシン生産能を付与又は増強するための方法としては、例えば、L-イソロイシン生合成系酵素から選択される1またはそれ以上の酵素の活性が増大するように細菌を改変する方法が挙げられる。そのような酵素としては、特に制限されないが、スレオニンデアミナーゼやアセトヒドロキシ酸シンターゼが挙げられる(特開平2-458号, FR 0356739, 及び米国特許第5,998,178号)。
L-バリン生産菌又はそれを誘導するための親株としては、L-バリン生合成系酵素から選択される1またはそれ以上の酵素の活性が増強された株が挙げられる。そのような酵素としては、特に制限されないが、ilvGMEDAオペロンやilvBNCオペロンの遺伝子にコードされる酵素が挙げられる。ilvBNはアセトヒドロキシ酸シンターゼを、ilvCはイソメロリダクターゼ(国際公開00/50624号)を、それぞれコードする。なお、ilvGMEDAオペロンおよびilvBNCオペロンは、L-バリン、L-イソロイシン、および/またはL-ロイシンによる発現抑制(アテニュエーション)を受ける。よって、酵素活性の増強のためには、アテニュエーションに必要な領域を除去または改変し、生成するL-バリンによる発現抑制を解除するのが好ましい。また、ilvA遺伝子がコードするスレオニンデアミナーゼは、L-イソロイシン生合成系の律速段階であるL-スレオニンから2-ケト酪酸への脱アミノ化反応を触媒する酵素である。よって、L-バリン生産のためには、ilvA遺伝子が破壊等され、スレオニンデアミナーゼ活性が減少しているのが好ましい。
E. coli W3110sucA::Kmr
E. coli AJ12624 (FERM BP-3853)
E. coli AJ12628 (FERM BP-3854)
E. coli AJ12949 (FERM BP-4881)
L-グルタミン生産能を付与又は増強するための方法としては、例えば、L-グルタミン生合成系酵素から選択される1またはそれ以上の酵素の活性が増大するように細菌を改変する方法が挙げられる。そのような酵素としては、特に制限されないが、グルタミン酸デヒドロゲナーゼ(gdhA)やグルタミンシンセターゼ(glnA)が挙げられる。
L-プロリン生産菌又はそれを誘導するための親株としては、L-プロリン生合成系酵素から選択される1またはそれ以上の酵素の活性が増強された株が挙げられる。L-プロリン生合成に関与する酵素としては、グルタミン酸5-キナーゼ、γ‐グルタミル-リン酸レダクターゼ、ピロリン-5-カルボキシレートレダクターゼが挙げられる。酵素活性の増強には、例えば、L-プロリンによるフィードバック阻害が解除されたグルタメートキナーゼをコードするproB遺伝子(ドイツ特許第3127361号)が好適に利用できる。
L-トリプトファン生産能、L-フェニルアラニン生産能、および/またはL-チロシン生産能を付与又は増強するための方法としては、例えば、L-トリプトファン、L-フェニルアラニン、および/またはL-チロシンの生合成系酵素から選択される1またはそれ以上の酵素の活性が増大するように細菌を改変する方法が挙げられる。
本発明の細菌には、lcfA遺伝子が導入されている。本発明の細菌は、上述のようなL-アミノ酸生産能を有する腸内細菌科に属する細菌に、lcfA遺伝子を導入することにより取得できる。また、本発明の細菌は、腸内細菌科に属する細菌にlcfA遺伝子を導入した後に、L-アミノ酸生産能を付与または増強することによっても得ることができる。なお、本発明の細菌は、lcfA遺伝子が導入されたことにより、L-アミノ酸生産能を獲得したものであってもよい。本発明において、本発明の細菌を構築するための改変は、任意の順番で行うことができる。
また、本発明の細菌は、さらに、脂肪酸資化能が高まるように改変されていてもよい。そのような改変としては、fadR遺伝子の発現を弱化すること、fadL、fadE、fadD、fadB、及びfadA遺伝子からなる群より選択される1またはそれ以上の遺伝子の発現を増強すること、cyoABCDEオペロンの発現を増強すること、およびそれらの組み合わせが挙げられる(特開2011-167071)。
以下に、タンパク質の活性を増大させる手法について説明する。
以下に、タンパク質の活性を低下させる手法について説明する。
本発明の方法は、脂肪酸を含有する培地中で本発明の細菌を培養すること、および該培地からL-アミノ酸を採取することを含む、L-アミノ酸の製造方法である。すなわち、本発明の方法においては、脂肪酸を炭素源として利用して、L-アミノ酸を発酵生産することができる。
<1-1>fadLDEBA遺伝子群導入株の構築の概要
本実施例では、fadL、fadD、fadE、fadB、fadAからなる遺伝子群を導入したエシェリヒア・コリL-リジン生産株を構築した。同遺伝子群は、脂肪酸のβ酸化経路の酵素をコードしている(Clark, D. P. and Cronan Jr., J. E. 1996. p. 343-357. In F. D. Neidhardt (ed.), Escherichia coli and Salmonella Cellular and Molecular Biology/Second Edition, American Society for Microbiology Press, Washington, D.C)。なお、fadBとfadAは、fadBAからなるオペロンを形成している。
fadEBAオペロン配列として、fadE遺伝子の上流にラムダファージのアタッチメントサイトとクロラムフェニコール耐性遺伝子を連結したDNA断片(att-cat)とtacプロモーター配列(Ptac) (Gene 25(2-3) 167-178 (1983))を連結したatt-cat-Ptac断片を有し、fadE遺伝子の下流にfadBA遺伝子を有するDNA断片を構築した。なおatt-cat-Ptac断片はpMW118-attL-Cm-attR(WO2005/010175)を参考に構築することが可能である。
WC196LCPtacfadEBAPtacfadLD株を、dapA、dapB、lysC、及びddh遺伝子を搭載したリジン生産用プラスミドpCABD2(WO95/16042)で常法に従い形質転換し、WC196LCPtacfadEBAPtacfadLD/pCABD2株を得た。
<2-1>lcfA遺伝子およびfadLEBA遺伝子群導入株の構築の概要
バチルス・ズブチリス由来のfadD遺伝子としてlcfA遺伝子(J. Biol. Chem. Vol. 282 No. 8 p.5180-5194)が報告されている。バチルス・ズブチリスの染色体の全塩基配列は既に明らかにされており(Nature 390:249-56 (1997))、この文献にはlcfA遺伝子の塩基配列が報告されている。配列番号17にlcfA遺伝子の塩基配列を、配列番号18にlcfA遺伝子によってコードされるアミノ酸配列を示す。まず、lcfA遺伝子の塩基配列に基づいてfadLlcfAオペロンを構築し、Red-driven integration法によるMG1655株の染色体上へ挿入した。次いで、fadLlcfAオペロンが挿入されたMG1655株をドナーとするP1トランスダクションにより、WC196LCPtacfadEBAの染色体上にfadLlcfAオペロンを挿入した。さらに、構築した株に組み込まれた抗生物質耐性遺伝子を、λファージ由来の切り出しシステムにより除去した。具体的な構築手順を以下に示す。
fadLlcfAオペロン配列として、fadL遺伝子の上流にtacプロモーター配列とT7ファージ10遺伝子上流配列由来のリボソーム結合部位(RBS)(Gene 73 (1988) 227-235)を有し、fadL遺伝子の下流にT7ファージ10遺伝子上流配列由来のリボソーム結合部位(RBS)とlcfA遺伝子を有するDNA断片を構築した。
WC196LCPtacfadEBAPtacfadLlcfA株を、dapA、dapB、lysC、及びddh遺伝子を搭載したリジン生産用プラスミドpCABD2(WO95/16042)で常法に従い形質転換し、WC196LCPtacfadEBAPtacfadLlcfA/pCABD2株を得た。
WC196LCPtacfadEBAPtacfadLlcfA/pCABD2株、WC196LCPtacfadEBAPtacfadLfadD/pCABD2株、および対照株WC196LC/pCABD2株(WO2006/078039)のグリセロールストックを融解し、各100 μLを、20 mg/Lのストレプトマイシンを含むLB寒天培地プレートに均一に塗布し、37℃にて24時間培養した。次いで、プレートのおよそ1/8量の菌体を、500 mL容三角フラスコの、60 mg/Lのストレプトマイシンを含む以下に記載の発酵培地40 mLに接種し、往復振とう培養装置で37℃において42時間培養した。本培養は、それぞれの株について2連で行った。本培養における炭素源としては、グルコース30g/Lおよびオレイン酸ナトリウム4g/L、またはグルコース20g/Lおよびオレイン酸ナトリウム3g/Lを用いた。また、乳化促進剤として、ポリ(オキシエチレン)ソルビタンモノオレイン酸エステル(Tween 80:ナカライテスク社製)を終濃度0.5%(w/v)となるように添加した。これらの株がTween80を資化できないことは、別途確認した。培養に用いた培地組成を以下に示す。
<炭素源>
グルコース 30 g/L
オレイン酸ナトリウム 4 g/L
または
グルコース 20 g/L
オレイン酸ナトリウム 3 g/L
<その他の成分>
(NH4)2SO4 24 g/L
KH2PO4 1 g/L
MgSO4・7H2O 1 g/L
FeSO4・7H2O 0.01 g/L
MnSO4・7H2O 0.008 g/L
Yeast Extract 2 g/L
Tween 80 5 g/L
CaCO3(日本薬局方) 22.5 g/L
KOHでpH7.0に調整し、120℃で20分オートクレーブを行なった。但し、炭素源とMgSO4・7H2Oは別滅菌した後、混合した。CaCO3は乾熱滅菌後に添加した。
配列番号1、2:fadE遺伝子断片増幅用PCRプライマー
配列番号3、4:att-cat-Ptac断片増幅用PCRプライマー
配列番号5、6:fadBA遺伝子断片増幅用PCRプライマー
配列番号7、8:att-cat-PtacfadEBA遺伝子断片増幅用PCRプライマー
配列番号9、10:fadL遺伝子断片増幅用PCRプライマー
配列番号11、12:att-cat-Ptac断片増幅用PCRプライマー
配列番号13、14:fadD遺伝子断片増幅用PCRプライマー
配列番号15、16:att-cat-PtacfadLfadD遺伝子断片増幅用PCRプライマー
配列番号17:Bacillus subtilisのlcfA遺伝子の塩基配列
配列番号18:Bacillus subtilisのLcfAタンパク質のアミノ酸配列
配列番号19、20:fadL遺伝子断片増幅用PCRプライマー
配列番号21、22:att-cat-Ptac断片増幅用PCRプライマー
配列番号23、24:lcfA遺伝子断片増幅用PCRプライマー
配列番号25、26:att-cat-PtacfadLlcfA遺伝子断片増幅用PCRプライマー
Claims (9)
- L-アミノ酸の製造方法であって、
L-アミノ酸生産能を有する腸内細菌科に属する細菌を、脂肪酸を含有する培地中で培養すること、および該培地からL-アミノ酸を採取すること、を含み、
前記細菌が、lcfA遺伝子が導入された細菌であり、
前記lcfA遺伝子が、下記(A)~(D)からなる群より選択されるDNAである、方法:
(A)配列番号18に示すアミノ酸配列を含むタンパク質をコードするDNA;
(B)配列番号18に示すアミノ酸配列において、1若しくは数個のアミノ酸の置換、欠失、挿入、又は付加を含むアミノ酸配列を含み、かつ、長鎖脂肪酸から脂肪酸アシルCoAを生成するとともに、内膜を通して取り込む活性を有するタンパク質をコードするDNA;
(C)配列番号17に示す塩基配列を含むDNA;
(D)配列番号17に示す塩基配列に相補的な塩基配列又は該塩基配列から調製され得るプローブとストリンジェントな条件下でハイブリダイズし、かつ、長鎖脂肪酸から脂肪酸アシルCoAを生成するとともに、内膜を通して取り込む活性を有するタンパク質をコードするDNA。 - 前記細菌が、さらに、脂肪酸資化能が高まるように改変されている、請求項1に記載の方法。
- 下記(a)~(d)のいずれかにより脂肪酸資化能が高まるように改変された、請求項2に記載の方法。
(a)fadR遺伝子の発現を弱化させること;
(b)fadL、fadE、fadD、fadB、及びfadA遺伝子からなる群より選択される1またはそれ以上の遺伝子の発現を増強させること;
(c)cyoABCDEオペロンの発現の発現を増強させること;
(d)それらの組み合わせ。 - 前記脂肪酸がオレイン酸である、請求項1~3のいずれか1項に記載の方法。
- 前記培地が、さらに、脂肪酸以外の炭素源を含有する、請求項1~4のいずれか1項に記載の方法。
- 前記脂肪酸以外の炭素源がグルコースである、請求項5に記載の方法。
- 前記L-アミノ酸がL-リジンである、請求項1~6のいずれか1項に記載の方法。
- 前記細菌がエシェリヒア属細菌である、請求項1~7のいずれか1項に記載の方法。
- 前記細菌がエシェリヒア・コリである、請求項8に記載の方法。
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---|---|---|---|---|
JP2011167071A (ja) * | 2008-05-22 | 2011-09-01 | Ajinomoto Co Inc | L−アミノ酸の製造法 |
Non-Patent Citations (4)
Title |
---|
BLACK, PN. ET AL.: "Cloning, sequencing, and expression of the fadD gene of Escherichia coli encoding acyl coenzyme A synthetase.", J BIOL CHEM, vol. 267, 1992, pages 25513 - 25520 * |
KUNST, F. ET AL.: "The complete genome sequence of the gram-positive bacterium Bacillus subtilis.", NATURE, vol. 390, 1997, pages 249 - 256 * |
MATSUOKA, H. ET AL.: "Organization and function of the YsiA regulon of Bacillus subtilis involved in fatty acid degradation.", J BIOL CHEM, vol. 282, 2007, pages 5180 - 5194 * |
WIPAT, A. ET AL.: "The dnaB-pheA (256 degrees- 240 degrees) region of the Bacillus subtilis chromosome containing genes responsible for stress responses, the utilization of plant cell walls and primary metabolism.", MICROBIOLOGY, vol. 142, 1996, pages 3067 - 3078 * |
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US20150218605A1 (en) | 2015-08-06 |
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