306 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 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 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 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 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.

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.

The application discloses an Escherichia coli probiotic with high beta-alanine yield and application thereof, and the recombinant genetically engineered bacterium takes a wild-type Escherichia coli probiotic as a starting strain and is subjected to one or more gene edits, including Trc promoter strengthening of a panD gene, an aspC gene, an sdhC gene and a ppc gene, overexpression of a panD gene from Bacillus subtilis, an aspB gene from Corynebacterium glutamicum, an aspA gene and a pyc gene from Corynebacterium glutamicum on a plasmid pTrc99a, and knockout of a cycA gene. 600 Compared with an existing reported Escherichia coli probiotic beta-alanine production strain, the OD of the recombinant genetically engineered bacterium is 4.4 times that of the existing reported strain, and the beta-alanine yield is 6 times that of the existing reported strain, so that the recombinant genetically engineered bacterium has great industrial application potential.

The invention discloses a corynebacterium glutamicum engineering strain produced by L-glutamine as well as a construction method and application of the corynebacterium glutamicum engineering strain. The corynebacterium glutamicum engineering strain is prepared by integrating a glutamine synthase encoding gene glnA which is sourced from saccharomyces cerevisiae and has a tyrosine residue mutation at the 99th site on the surface and an sRNA-MicC-EcHfq regulation module of a targeted adenylyltransferase gene glnE into a vector plasmid; the method comprises the following steps: constructing a recombinant plasmid for removing adenosine acylation of glutamine synthase; and transferring the recombinant plasmid into corynebacterium glutamicum of which the odhA gene expression is controlled by a growth stage specific promoter Pcg2705, so as to obtain a corynebacterium glutamicum engineering strain for producing L-glutamine. According to the invention, through multi-gene synergistic modification and space-time metabolic flux optimization, the problem of'growth-synthesis' tradeoff in the prior art is solved, the fermentation efficiency is improved, the fermentation process is simple, and the application prospect is good.

The invention relates to the technical field of synthesis of natural dyes by a biological method, in particular to an antibiotic-demand-free ornamental blue high-yield strain as well as construction and application of the antibiotic-demand-free ornamental blue high-yield strain. Corynebacterium glutamicum is used as an initial strain, a tricarboxylic acid circulating gene is regulated and interfered, and the copy number of exogenous blue pigment synthetase BpsA in a genome is adjusted, so that the ornamental blue high-yield strain is obtained. The strain does not need to use antibiotics in the fermentation process, the yield is stable, the product production capacity equivalent to the level when antibiotics are used can still be achieved through fermentation under the antibiotic-free condition, and the growth performance of the strain is kept. The method for producing the ornamental blue by using the strain provided by the invention ensures that the ornamental blue product is natural and green, also improves the efficient production capacity of the strain, solves the contradiction between green environmental protection and stable high yield of the ornamental blue dye, is green and environment-friendly, and has a remarkable industrial application prospect.

The invention discloses a rigorous induction system for corynebacterium glutamicum and application of the rigorous induction system, and belongs to the fields of genetic engineering and microbiology. The system can be strictly regulated when an inducer is not added, and can express only after the inducer is added. More specifically, the invention relates to the reduction of leak expression of Cre recombinase by comprising a logic gate, repression regulation and RNA regulation elements, and the use thereof for mediating SCRaMbLE to produce large-scale genome random rearrangement in Corynebacterium glutamicum synthetic genomes. Particularly, the method is used for reducing the leakage expression level of Cre recombinase and keeping the moderate expression level after induction. More importantly, the rigorous induction system disclosed by the invention can be applied to genome rearrangement to obtain rearranged strains with highly diversified genotype sequences, so that the purpose of increasing the yield of target products or enhancing the stress resistance of the strains is achieved.

The invention relates to the field of synthetic biology, metabolic engineering and fermentation engineering, and discloses a genetically engineered bacterium and application thereof in production of alpha-ketoglutaric acid.The genetically engineered bacterium comprises the steps that the genetically engineered strain with escherichia coli BW25113 or corynebacterium glutamicum ATCC13032 as a host is constructed; overexpression type isocitrate dehydrogenase genes are integrated through chromosomes, alpha-ketoglutarate dehydrogenase complex genes are knocked out, NADPH invertase is overexpressed through plasmids, and exogenous AKG transporter protein is introduced, so that metabolic flux directional regulation and control and product efflux enhancement are realized; meanwhile, a staged fermentation process is adopted and comprises dynamic gradient adjustment of inorganic phosphorus concentration and two-stage pH control. According to the method, the AKG yield of 78.2 g / L can be obtained under the 5L tank scale, the sugar acid conversion rate reaches 0.68, and the method has the advantages of being high in yield, low in byproduct and controllable in cost. The obtained AKG is suitable for a plurality of fields such as medical intermediates, functional foods and cell culture additives, and has wide industrial application prospects.

The invention relates to the technical field of microbial metabolism engineering, and discloses a genetically engineered bacterium for producing L-ornithine as well as a construction method and application of the genetically engineered bacterium. According to the genetically engineered bacterium provided by the invention, putrescine synthesis pathway genes speC, speF and argF are knocked out in a genome of the genetically engineered bacterium, a dynamic regulation gene argI is achieved, an L-ornithine synthesis pathway gene cluster derived from corynebacterium glutamicum is over-expressed at a mazG site, a gene argG is knocked down, transcription of a proline pathway gene proB is controlled at a temperature on the genome, and the gene engineering bacterium is obtained. An efflux protein coding gene lysE which is started by a promoter PLtetO-1 and is derived from corynebacterium glutamicum is inserted into a trpR site, and an original promoter of an argO gene on a genome is replaced by the promoter PLtetO-1, so that synthesis and degradation pathways of L-ornithine are reasonably optimized, and expression of a competitive pathway and an efflux-related gene is controlled through temperature change, so that the yield of L-ornithine is increased, and the yield of L-ornithine is increased. In the fermentation process, normal growth of thalli can be maintained without adding arginine, and finally high yield of L-ornithine is achieved.

The invention discloses a corynebacterium glutamicum whole genome random mutation tool and application thereof, and belongs to the technical field of genetic engineering and biological mutagenesis. DsDNA is unwound in the transcription process based on DNA helicase, DNA adenine deaminase and the DNA helicase are fused, and whole-genome random mutation of corynebacterium glutamicum is achieved. The whole genome random mutation method disclosed by the invention is applied to mutagenesis of an original strain of Corynebacterium glutamicum ATCC 13032, and a mutant strain of which the biomass is 1.95 times of that of WT (OD600 is 2.2) and 1.99 times of that of WT / pXMJ19 (OD600 is 2.16) when being cultured under the condition that the pH value is 5.5 is obtained. The corynebacterium glutamicum whole genome random mutation method disclosed by the invention has important guiding significance for screening other mutation strains with enhanced robustness.

The invention discloses a CgGlmS mutant and application of the CgGlmS mutant in synthesis of N-acetylglucosamine (GlcNAc) from corynebacterium glutamicum, and belongs to the technical field of biology. According to the invention, a bottleneck enzyme CgGlmS in a synthetic route of N-acetylglucosamine is subjected to deep rational analysis and semi-rational transformation. Through systematic research on the structure and function of an original CgGlmS enzyme from corynebacterium glutamicum S9114, the efficient CgGlmS mutant A253M is successfully screened out, and the enzyme activity, stability and catalytic efficiency of the mutant are obviously improved compared with those of a wild type. The mutant CgGlmS is overexpressed in corynebacterium glutamicum S9114 by using plasmids, so that the yield of N-acetylglucosamine in corynebacterium glutamicum is increased. The CgGlmS enzyme is directionally modified, so that the catalytic efficiency of the CgGlmS enzyme is improved, accumulation of N-acetylglucosamine in corynebacterium glutamicum is further promoted, and powerful support is provided for efficient production of the corynebacterium glutamicum.

The invention discloses a construction method of recombinant corynebacterium glutamicum for fermentation synthesis of poly beta-(1, 6)-N-acetylglucosamine polysaccharide, and belongs to the technical field of bioengineering. The recombinant corynebacterium glutamicum capable of preparing the PNAG through fermentation is constructed by using synthetic biology and genetic engineering technologies for the first time, cheap carbon sources and nitrogen sources can be utilized, the recombinant corynebacterium glutamicum is suitable for high-density fed-batch fermentation, and the generation cost of the PNAG is reduced; the yield after 42 hours of fermentation can reach 6.82 g / L, and the method has industrial application potential.

The invention provides a strain for producing L-2-aminobutyric acid as well as a construction method and application of the strain. According to the strain, E.coli W3110 is taken as a chassis strain, tdh, rhtA and ilvE genes are knocked out, the transcriptional levels of ppc, aspC, thrAfbrBC, ilvAfbr, tdcB, yaS and pntAB genes are up-regulated, an ilvI gene is weakened, bcd and gdh genes derived from bacillus subtilis B.subtilis 168 and a cysK gene derived from Corynebacterium glutamicum K051 are introduced in a heterologous manner, and the L-2-aminobutyric acid producing strain is obtained through screening and screening. The strain does not contain plasmids, is stable in heredity, does not need induction, does not need to add resistant substances, efficiently synthesizes L-2-aminobutyric acid from the beginning by taking glucose as a substrate, and has good L-2-aminobutyric acid synthesis capability, stable performance and high acid production efficiency.

The invention discloses Escherichia coli probiotics with high yield of beta-alanine and application of the Escherichia coli probiotics. The recombinant genetically engineered bacterium takes wild type Escherichia coli probiotics as a starting strain, and edits one or more of the following genes: a Trc promoter enhanced panD gene, an aspC gene, an sdhC gene and a ppc gene; a panD gene from bacillus subtilis, an aspB gene and an aspA gene from corynebacterium glutamicum and a pyc gene from corynebacterium glutamicum are over-expressed on a plasmid pTrc99a, and a cycA gene is knocked out. Compared with the existing reported Escherichia coli probiotic beta-alanine production strain, the OD600 of the recombinant genetic engineering strain is 4.4 times of that of the existing reported strain, the yield of beta-alanine is 6 times of that of the existing reported strain, and the recombinant genetic engineering strain has huge industrial application potential.

The invention discloses a screening and expression platform construction method for non-essential gene loci of corynebacterium glutamicum, and belongs to the technical field of biology. The center sites CGLRS02940, CGLRS03085, CGLRS08555, CGLRS09020 and CGLRS13560 of the corynebacterium glutamicum identified by the invention have the remarkable advantages that when gene knockout or knockin operation is carried out, the sites do not interfere with the normal physiological metabolism process of strains, and stable expression of exogenous genes can be guaranteed; meanwhile, the gene editing efficiency is relatively high, and an editing target with high universality and high reliability is provided for genetic engineering modification of corynebacterium glutamicum.