393 results about "Corynebacterium glutamicum" patented technology

The invention discloses construction and application of an L-malic acid producing issatchenkia orientalis strain, and belongs to the technical field of microorganisms and the technical field of microbial fermentation and metabolic engineering. Through a metabolic engineering means, a cytoplasm metabolic pathway of an issatchenkia orientalis strain is transformed, and a pyruvate decarboxylase coding gene, glycerol dehydrogenase and lactic dehydrogenase are knocked out; a pyruvate carboxylase gene derived from aspergillus flavus, a malate dehydrogenase gene derived from corynebacterium glutamicum and phosphoenolpyruvate carboxylase derived from escherichia coli are screened and integrated, so that a cytoplasm rTCA cycle synthesis pathway is enhanced; inserting a dicarboxylic acid external transporter gene from schizosaccharomyces cerevisiae at a neutral site GD21, and knocking out endogenous dicarboxylic acid internal transporter; the L-malic acid yield of the modified yeast strain in the fermentation process is remarkably increased and reaches 140.16 g / L. The engineering strain provided by the invention has good industrial application potential in efficient L-malic acid production.

The invention belongs to the field of molecular biology, and particularly relates to a construction method of corynebacterium glutamicum for producing L-amino acid. According to the method, a CgtR2-CgtS2 double-component system in the strain is weakened, so that the yield and the conversion rate of L-amino acid, especially L-glutamic acid, of the strain are improved. The invention also provides an engineering strain constructed by using the method, and a method for producing L-amino acid by using the strain and improving the yield and conversion rate of the L-amino acid. The production cost of the L-amino acid can be reduced, and a new strategy is provided for large-scale production.

The invention discloses a method for improving growth of corynebacterium glutamicum under high-temperature stress, and aims to overcome the problems of abnormal growth and metabolism, even death and the like caused by temperature rise of existing microorganisms in an industrial fermentation production process, adaptive laboratory evolution is adopted, corynebacterium glutamicum ATCC 13032 is used as an original strain, and the corynebacterium glutamicum ATCC 13032 is used as an original strain. And carrying out heat stress subculture for 42.9 days, and separating out the strains HES1 and HES2 with improved high temperature resistance. The whole genome is re-sequenced to obtain mutant elements cspB and gltA which enable the strain to generate high-temperature adaptive change. And carrying out high-temperature test on the abrupt change element. In specific implementation, the two mutants are respectively overexpressed, and in a test, compared with a control strain WT, the 42-DEG C high-temperature tolerance is respectively improved by about 14.4% and 7%. Therefore, the beneficial mutant obtained through adaptive laboratory evolution lays a good foundation for application of corynebacterium glutamicum in industrial high-temperature conditions.

The invention discloses a transcription factor Cgl2988 related to production of 5-aminolevulinic acid based on network model prediction and application, the amino acid sequence of the transcription factor Cgl2988 is as shown in SEQ ID NO.1. The transcription factor Cgl2988 related to production of 5-ALA is simulated and predicted based on a metabolic network model system mcCGL, and experiments prove that the transcription factor Cgl2988 related to production of 5-ALA has the advantages that the transcription factor Cgl2988 related to production of 5-ALA can be used for preparing the transcription factor Cgl2988 related to production of 5-ALA; the expression strain Cgh3-low-cgl2988 of the transcription factor gene cgl2988 in the down-regulated corynebacterium glutamicum is subjected to shake flask fermentation, and the yield of 5-ALA is 5.52 + / -0.19 g / L and is increased by about 1.64 times compared with that of a control strain; the expression strain Cgh3-pX-cgl2988 of the transcription factor gene cgl2988 in the up-regulated corynebacterium glutamicum is subjected to shake flask fermentation, and the yield of the 5-ALA is 5.76 + / -0.11 g / L, which is about 2.84 times higher than that of a control strain.

The invention discloses corynebacterium glutamicum for producing N-acetylglucosamine and application of the corynebacterium glutamicum, and belongs to the technical field of synthetic biology. Specifically, the corynebacterium glutamicum overexpresses a GNA1 gene from a brewer's yeast S288C controlled by a tacM promoter, a glmS gene from corynebacterium glutamicum S9114 and a yqab gene from escherichia coli K12 MG1655, and simultaneously has five gene defect types of nagA, nagB, ldhA, msccg and msccg2 in a genome and two gene single base mutation types of odhA and glnA, and the codon of the glnA for coding the 405th amino acid is mutated from TAC to TTC. By blocking excretion of glutamic acid of corynebacterium glutamicum and enhancing conversion of glutamic acid to glutamine, the supply capacity of a precursor of corynebacterium glutamicum is enhanced, and an optimal way for synthesizing N-acetylglucosamine is obtained, so that efficient production of N-acetylglucosamine in corynebacterium glutamicum is realized, and the yield of N-acetylglucosamine in corynebacterium glutamicum is increased. The method has important economic value and social significance.

The invention discloses corynebacterium glutamicum for producing L-isoleucine and application of the corynebacterium glutamicum. The strain is obtained by performing ultraviolet mutagenesis and structural analogue resistance screening on corynebacterium glutamicum ATCC13869. According to the method, the L-isoleucine can be produced through direct fermentation of glucose, the yield of the L-isoleucine can reach 51.69 g / L, the conversion rate can reach 28.5%, the production efficiency is improved, meanwhile, the main raw material glucose used for fermentation is low in price and easy to obtain, the method conforms to the green food safety production concept, and industrial production of the L-isoleucine is facilitated.

The invention discloses a spermidine synthetase mutant and application of the spermidine synthetase mutant in synthesis of spermidine, and belongs to the technical field of genetic engineering and metabolic engineering. According to the method, the spermidine synthetase is mutated firstly, the efficiency of the spermidine synthetase is improved, and on the basis, the dissolved oxygen and fed-batch concentration are optimally controlled through fermentation, so that the yield of spermidine is improved. The corynebacterium glutamicum provided by the invention is an engineering bacterium with plasmids and without defects, and after the corynebacterium glutamicum is subjected to fed-batch fermentation in a 5L fermentation tank for 68 hours, the yield of spermidine reaches 25.1 g / L, and the sugar-acid conversion rate is 17.9%.

The present application relates to the technical field of biocatalysis and biosynthesis, and specifically discloses a natural blue pigment and a biosynthesis method therefor. The present application uses metabolically engineered bacteria to express indigoidine synthetase and phosphopantetheinyl transferase, to catalyze glutamine and N-acetylglutamine to biosynthesize a natural blue pigment N-acetylindigoidine, and deduces its molecular structure by means of mass spectrometry, nuclear magnetic resonance and other methods. The present application achieves catalytic synthesis of N-acetylindigoidine from glutamine and N-acetylglutamine in Escherichia coli, Corynebacterium glutamicum, Saccharomyces cerevisiae and Streptomyces. Compared with indigoidine, N-acetylindigoidine has a maximum absorption wavelength of 584 nm, possesses better color brightness, and has more stable coloration that is not easily faded, with a very broad application range and industrial production application prospects.

The invention provides construction and application of a hyaluronic acid recombinant bacterium, and belongs to the fields of biochemical engineering, synthetic biology, genetic engineering and metabolic engineering, the recombinant corynebacterium glutamicum contains a hyaluronic acid synthase gene, a UDP-glucose dehydrogenase gene and a glutamide-6-phosphate fructose transaminase gene; the hyaluronic acid synthase gene, the UDP-glucose dehydrogenase gene and the glutamine-6-phosphate fructose transaminase gene are respectively connected with a sequence RBS1, a sequence RBS2 and a sequence RBS3; the recombinant bacterium provided by the invention also contains a dCas9 protein gene dCas9 and any one of genes sgRNA1, sgRNA2, sgRNA3, sgRNA4, sgRNA5 and sgRNA6, and the recombinant bacterium provided by the invention is high in hyaluronic acid yield and low in production cost.

The invention discloses three novel corynebacterium glutamicum heat-resistant elements and application thereof, and belongs to the technical field of bioengineering. Three heat-resistant genes are obtained from corynebacterium glutamicum research. The heat-resistant gene and a promoter Ptuf are connected and are combined and transformed in corynebacterium glutamicum. The heat-resistant element is introduced into a plasmid and is expressed in corynebacterium glutamicum. After 24 hours of high-temperature culture at 42 DEG C, the OD600 of the corynebacterium glutamicum containing the heat-resistant element and the plasmid is improved, and the growth condition of the corynebacterium glutamicum at 42 DEG C is obviously superior to that of the starting corynebacterium glutamicum. Therefore, the heat-resistant elements can obviously improve the heat resistance of corynebacterium glutamicum under a high-temperature culture condition. The method has important application value in improvement of the thermal stability of corynebacterium glutamicum and industrial production prospect.

The present application relates to the technical field of biocatalysis and biosynthesis, and specifically discloses a blue pigment and a biosynthesis method thereof. In the present application, an indigoidine synthetase and a 4′-phosphopantetheinyl transferase are expressed by a metabolically engineered strain to catalyze the biosynthesis of the blue pigment N-acetyl-indigoidine from glutamine and N-acetylglutamine, and a molecular structure of the blue pigment is inferred by mass spectrometry, nuclear magnetic resonance spectroscopy, etc. The present application achieves the catalytic synthesis of N-acetyl-indigoidine from glutamine and N-acetylglutamine in Escherichia coli (E. coli), Corynebacterium glutamicum (C. glutamicum), Saccharomyces cerevisiae (S. cerevisiae), and Streptomyces. Compared with indigoidine, N-acetyl-indigoidine has a maximum absorption wavelength of 584 nm, and a stable color having high brightness that is not easy to fade. Thus, the blue pigment shows an extensive application range and a promising industrial production prospect.

The invention relates to the technical production field of metabolic engineering and genetic engineering, and particularly provides a genetically engineered bacterium for producing 2 '-deoxyuridine as well as a construction method and application of the genetically engineered bacterium. According to the strain, deoxyuridine kinase tdk is knocked out on an E.coli W3110 genome, and T7 RNA polymerase is integrated; an aspartate transaminase gene aspC, a glutamine synthetase gene glnA, a 5 '-deoxynucleotidase gene yfbR and a uridine monophosphate kinase gene pyrH are subjected to overexpression; the method comprises the following steps: introducing a ribonucleoside diphosphate reductase gene nrdBCA from Escherichia phage T4 in a heterologous series connection manner; the CTP synthase gene pyrG * of Corynebacterium glutamicum is introduced in a heterologous mode, and the CTP synthase gene pyrG * of Corynebacterium glutamicum is introduced in a heterologous mode. The safe, efficient and low-cost production of the 2 '-deoxyuridine is realized.

The invention belongs to the technical field of biology, and particularly relates to a heat-resistant element newly derived from Thermus thermophilus and application of the heat-resistant element. The heat-resistant gene is derived from Thermus thermophilus, is connected with a promoter and is transformed into Corynebacterium glutamicum. Experimental results show that after the corynebacterium glutamicum is cultured at the high temperature of 42 DEG C for 24 hours, the OD600 of the corynebacterium glutamicum carrying the heat-resistant elements and plasmids is obviously higher than that of a control strain ATCC 13032, which indicates that the corynebacterium glutamicum has obviously better growth capability under the high-temperature condition than that of a starting strain, and the effectiveness of the heat-resistant elements in the aspect of improving the heat resistance of the strains is verified. The method is of great significance to improvement of the thermal stability of the corynebacterium glutamicum and application prospects of the corynebacterium glutamicum in industrial production.

The invention provides an L-lysine production strain and a construction method and application thereof.E.coliW3110 serves as an original strain, pflB, adhE, ldhA, ackA, frdBC, poxB, lacI, cadA and ldcC genes are knocked out, pntAB, ppc, aspC, lysCV339A, asd, dapAH56K, dapB, lysA and lysE genes are up-regulated, ddh genes derived from Corynebacterium glutamicum K051 are heterologously expressed, part of by-products and lysine decomposition pathway enzymes are knocked out of the strain, the diaminopimelic acid pathway of the strain and supply of NADPH are enhanced, and the L-lysine production strain has the advantages that the L L-lysine can be efficiently synthesized by taking glucose as a substrate, and the method has a relatively high production level.

The present invention provides a 5-hydroxytryptophan production strain and a construction method and application thereof. The strain has a clear genetic background and is effective in producing 5-hydroxytryptophan. E.coli HTP11 Subtilis subtilis spores pureF bsu K316Q Mutated gene, upregulated strain E.coli HTP11 of guaB , guaA , gmk , ndk The transcription level of the gene was increased by heterologous introduction of the gapX Gene, missing aromatic amino acid transporter serB , tnaB , aroP Gene, up-regulated inner membrane efflux transporter yhjV The transcription level of the gene was increased and electroporated into the pTm-serB plasmid, which could stably provide 5-hydroxytryptophan, the direct precursor of 5-hydroxytryptophan, and had a high efficiency of 5-hydroxytryptophan output.

The present invention relates to an enzyme catalyst for preparing a dicarboxylic acid and a method for preparing a dicarboxylic acid using the same. The enzyme catalyst is prepared by a method comprising the following steps: (1) carrying out fermentation culture on enzyme-producing microorganisms in a culture medium to obtain a crude enzyme solution, and (2) immobilizing the crude enzyme solution on a molecular sieve to obtain the enzyme catalyst, wherein the enzyme producing microorganisms are selected from candida tropicalis, candida sake, pichia pastoris, saccharomyces cerevisiae, lactobacillus brevis, corynebacterium glutamicum, bacillus subtilis, bacillus cereus, escherichia coli and pseudomonas aeruginosa. The method comprises the following steps: in a PBS buffer solution, mixing triglyceride with the enzyme catalyst, and carrying out catalytic reaction under stirring at 20-50 DEG C; and then carrying out hydrolysis reaction at the temperature of 250-300 DEG C under the pressure of 30-100 bar. According to the method, the enzyme catalyst and the molecular sieve are immobilized, so that other oxidants or catalysts are not required to be added while the dicarboxylic acid with higher yield is obtained.

The invention relates to the technical field of microbial metabolism engineering, in particular to a corynebacterium glutamicum producing strain for efficiently producing D-pantothenic acid as well as a construction method and application of the corynebacterium glutamicum producing strain. The construction method specifically comprises the following steps: (1) by taking wild corynebacterium glutamicum ATCC 13032 as a chassis, weakening ilvA, and constructing DPA1 through mutation expression; (2) knocking out the quinone pyruvate oxidoreductase and inserting a panBCE gene expression cassette into the quinone pyruvate oxidoreductase to construct DPA2; (3) introducing and using a pEC-xk99E overexpression plasmid to screen and express Escherichia coli W3110, Bacillus subtilis 168, and endogenous acetohydroxy acid synthase, acetolactate isomerized reductoisomerase and 2-hydroxy acid dehydratase, and carrying out a step (2) of carrying out a step (3) of screening and expressing the Escherichia coli W3110, Bacillus subtilis 168, and endogenous acetohydroxy acid synthase, acetolactate isomerized reductoisomerase and 2-hydroxy acid dehydratase in the DPA2; and (4) under the control of a strong promoter, carrying out tandem overexpression on the screened ilvBNCD gene by using pEC-xk99E, constructing DPA3, and enhancing a pantothenic acid main synthesis pathway and an upstream pathway pulling force, thereby obtaining the corynebacterium glutamicum for efficiently producing D-pantothenic acid. The strain provided by the invention can produce D-pantothenic acid with high yield and high conversion rate by utilizing a carbon source, and has important industrial application value.

The invention belongs to the technical field of synthetic biology, and particularly relates to recombinant escherichia coli for efficiently producing O-acetyl-L-homoserine as well as a construction method and application of the recombinant escherichia coli. According to the invention, CRISPR-Cas9 gene editing is combined with metabolic modification, so as to precisely integrate OAH biosynthesis key nodes: introducing and overexpressing a mutant metX gene at a genome pseudogene site to enhance the expression of homoserine acetyltransferase, knocking out byproducts such as poxB and mgsA to synthesize genes, and carrying out high-yield synthesis of OAH. Corynebacterium glutamicum thrA (anti-feedback inhibition), aspB and bacillus subtilis acsA-acuA genes (construction of an acetic acid switch) are introduced, gene expression of gltA, tpiA and the like is optimized to increase supply of precursors such as acetyl CoA and the like, and finally a stable strain without plasmids, antibiotics and inducers is obtained. The production cost is effectively reduced, and the method has the advantage of high genetic stability and shows a good application prospect in OAH industrial production.

The invention discloses a production strain for fermenting L-histidine and application of the production strain, and belongs to the technical field of biological engineering. According to the invention, escherichia coli E.coli CICC 10243 is taken as an original strain, histidine synthesis operon genes hisDCB-cg2302-cg2301-HA-impA-FI, hisN and hisEG from corynebacterium glutamicum are integrated on a genome of the escherichia coli E.coli CICC 10243, a pyruvate dehydrogenase AceE mutant coding gene is introduced, and an escherichia coli transcription factor SlyA coding gene slyA is inactivated. The novel strain E.coli His08 for fermentation production of L-histidine is prepared and fermented in a 5L fermentation tank for 60 h, the histidine yield reaches 58.39 g / L, the sugar-acid conversion rate is 0.15 g / g, and the strain E.coli His08 has important application value.

Provided are methods, prokaryotic host cells, expression vectors, and kits for the production of psilocybin derivatives produced using at least one psilocybin production gene. The methods enable production of psilocybin derivatives and related compounds including non-naturally occurring species. In certain embodiments, a prokaryotic host cell is selected from the group consisting of from the group consisting of Escherichia coli, Corynebacterium glutamicum, Vibrio natriegens, Bacillus subtilis, Bacillus megaterium, Escherichia coli Nissle 1917, Clostridium acetobutlyicum, Streptomyces coelicolor, Lactococcus lactis, Pseudomonas putida, Streptomyces clavuligerus, and Streptomyces venezuelae.

The invention discloses a method for producing 5-aminolevulinic acid by inhibiting expression of a global transcriptional regulatory factor gene mcbR in corynebacterium glutamicum. The method comprises the following steps: (1) constructing a pCRISPRi-mid-McbR plasmid and a pCRISPRi-high-McbR plasmid; (2) respectively introducing the plasmids into corynebacterium glutamicum Cgh3 through electrotransfection, verifying by using a bacterial colony PCR (Polymerase Chain Reaction) mode to obtain an expression strain Cgh3-m-McbR or Cgh3-h-McbR for inhibiting a global transcriptional regulation factor gene mcbR in the corynebacterium glutamicum, and fermenting to obtain 5-aminolevulinic acid; experiments prove that compared with a control strain Cgh3-pXi, the strain for inhibiting the expression of the global transcriptional regulation factor gene mcbR in corynebacterium glutamicum has the advantage that the yield of 5-aminolevulinic acid is increased by 1.27 times or more after fermentation.

The invention discloses a recombinant strain for biosynthesis of gamma-aminobutyric acid as well as a construction method and application of the recombinant strain, and belongs to the technical field of gene engineering. In order to solve the technical problems that GAD (gamma-aminobutyric acid) is seriously limited to be synthesized by corynebacterium glutamicum by adopting a cell surface display technology because the growth of corynebacterium glutamicum and the production of GABA (gamma-aminobutyric acid) have difference on pH (potential of hydrogen) requirements and L-glutamic acid has a feedback inhibition effect on the synthesis process of the L-glutamic acid, the invention adopts a cell surface display technology to display GAD on the outer surface of a cell. Therefore, the GAD not only can exert higher activity in a more suitable meta-acidic environment, but also can directly convert a precursor L-glutamic acid continuously secreted to extracellular into extracellular GABA, and extracellular transport of the GABA does not need to be carried out any more. Furthermore, in order to more efficiently and simultaneously transform intracellular and extracellular L-glutamic acid, GAD is expressed in cells on the basis of displaying GAD on the surfaces of the cells, so that the L-glutamic acid is simultaneously transformed in the cells and extracellular, and synthesis of GABA (gamma-aminobutyric acid) is accelerated.

The invention provides a beta-alanine producing strain as well as a construction method and application thereof. According to the bacterial strain, an acetaldehyde dehydrogenase gene adhE, a lactic dehydrogenase gene ldhA, an acetokinase gene ackA, a pyruvate dehydrogenase gene poxB, a DNA binding transcription inhibition factor coding gene lacI, an aspartate kinase thrA, a pantothenic acid synthase gene panC, an alanine synthesis transaminase gene cycA and an alanine synthesis transaminase gene yfbQ are knocked out from an E.coli W3110 genome, and the bacterial strain is obtained. A phosphoenolpyruvate carboxylase gene ppc, a pyridine nucleotide transhydrogenase coding gene pntAB, an aspartic acid transaminase gene aspC, an aspartic acid decarboxylase gene panD derived from pseudomonas aeruginosa and a beta-alanine transporter gene NCgl0580 derived from corynebacterium glutamicum are integrated at the same time, and the bacillus subtilis is used for producing beta-alanine and has the advantage of high fermentation yield.

The invention discloses a construction method of a cyanobacteria-corynebacterium glutamicum artificial photosynthetic mixed bacteria system. The construction method comprises the following steps: step S1, amplifying by taking plasmid pUC-tho as a template to obtain a theophylline inducible promoter Ptho; step S2, carrying out amplification by taking a Synechocystis sp. PCC 6803 genome as a template so as to obtain a strong promoter Pcpc560, and carrying out amplification on the strong promoter Pcpc560 so as to obtain a strong promoter Pcpc560; step S3, carrying out amplification by taking the plasmid pUC-PAL as a template to obtain an arabidopsis thaliana phenylalanine lyase gene pal; step S4, carrying out amplification by taking the plasmid pUC-cscB as a template to obtain an escherichia coli W sucrose transporter gene cscB; step S5, carrying out amplification by taking the integrated plasmid Pcp3031 as a template, so as to obtain a terminator Trbcl; and step S6, fusing the strong promoter Pcpc560, the arabidopsis phenylalanine lyase gene pal and the terminator Trbcl, and respectively connecting with an expression vector pSI-SPE to obtain the expression vector containing the gene pal. According to the invention, a'cyanobacteria-corynebacterium glutamicum 'artificial photosynthetic mixed bacteria system is constructed by simulating a mutualistic symbiotic relationship ubiquitous in nature, and negative carbon biosynthesis of cis-muconic acid is realized.

The invention provides an L-arginine production strain and a construction method and application thereof, corynebacterium glutamicum AJC is modified by a metabolic engineering method to obtain the L-arginine production strain, the synthesis path of arginine is optimized, and a carbon source efficiently flows to arginine by means of promoter replacement, multi-copy and the like; by introducing an exogenous gene pyrABE949 *, the supply of a precursor substance carbamyl phosphate is enhanced; by introducing an exogenous gene pntAB, a new direction is provided for supply of coenzyme NADPH, and a large amount of reducing power is provided for synthesis of arginine; an exogenous gene fxpk is introduced, an NOG system is constructed, an acetyl coenzyme A pool is enriched, a large number of acetyl coenzyme A precursors are provided, and the engineering bacterium has the characteristics of high yield and stability and has good industrial application value in the aspect of fermentation production of L-arginine.

The invention relates to the technical field of food microorganisms, fermentation and seasonings, in particular to a natural fermentation flavor enhancer as well as a preparation method and application thereof. The natural fermentation flavor enhancer comprises 3-40 wt% of glutamic acid of a natural source and 0.2-25 wt% of IMP and / or GMP of a natural source. Wherein the natural fermented flavor enhancer is obtained by a method comprising fermentation by using microorganisms, and the microorganisms are selected from two or more of yeast, lactic acid bacteria, brevibacterium ammoniacum and corynebacterium glutamicum and at least comprise one of yeast or lactic acid bacteria. The natural fermented flavor enhancer is obtained through mixed fermentation of microorganisms, the flavor and taste of the flavor enhancer are improved, and astringency and peculiar smell of the product are eliminated; the natural substrate is adopted for fermentation, no additive is contained, and the requirements for greenness, safety and health are met.

The invention provides a method for improving fermentation yield of glutamine, which is characterized in that a coding gene aspB of aspartate transaminase in a microorganism with glutamine production capacity is weakened by utilizing a genetic engineering means to obtain a modified microorganism, and the modified microorganism is used for fermentation production of glutamine. The aspB gene of corynebacterium glutamicum is modified, so that the glutamine generation capacity of corynebacterium glutamicum is higher than that of an unmodified strain.

A C. glutamicum strain has enhanced productivity of L-lysine, and a method produces L-lysine using the C. glutamicum strain. The C. glutamicum strain expresses NAD(P)(+) transhydrogenase subunit alpha PntA and NAD(P)(+) transhydrogenase subunit beta PntB combined with increased activity of the myo-inositol transporter IolT. A method produces L-lysine in a fermentative process employing such C. glutamicum strain.

The embodiment of the invention discloses a recombinant III-type humanized collagen as well as a preparation method and application thereof. The amino acid sequence of the recombinant III-type humanized collagen is shown as SEQ ID NO.1, SEQ ID NO.2 or SEQ ID NO.3. The recombinant III-type humanized collagen has the advantages that the recombinant III-type humanized collagen can be used for preparing the recombinant III-type humanized collagen; the recombinant III-type humanized collagen provided by the invention has the activity of promoting cell adhesion, the amino acid sequence of the recombinant III-type humanized collagen is selected from the amino acid sequence of natural collagen, and the recombinant III-type humanized collagen does not generate immune response when being applied to a human body. The characteristic that corynebacterium glutamicum does not secrete endotoxin is utilized, the preparation method is simple, the product can meet the requirements of food, cosmetics, medical instruments and drugs without complex separation, and reference is provided for low-cost industrial production.

Provided are a theanine-producing strain and use thereof in tea fermentation production. A corynebacterium glutamicum is proposed, which includes an alanine decarboxylase CsAlaDC mutant. The theanine-producing strain is obtained by taking the corynebacterium glutamicum as a starting strain, knocking out in sequence an α-ketoglutarate dehydrogenase E1 subunit gene odhA, a glutamate external transporter gene Ncg11221 and a lactate dehydrogenase gene ldh; and / or expressesing a citrate synthase gene gltA, a pyruvate kinase gene pyk and a glutamate dehydrogenase gene gdh; and / or overexpressing an alanine dehydrogenase alaA and integrating a γ-glutamine synthetase GMAS into a cg1960 pseudogene locus of the corynebacterium glutamicum.