332 results about "Microbacterium" patented technology

The invention discloses lactobacillus mucus HG002 and application thereof, and belongs to the field of microbial medicine. The lactobacillus mucilaginosus HG002 is preserved in the China General Microbiological Culture Collection Center (CGMCC), the preservation number is CGMCC NO.36670, and the 16S rDNA gene sequence of the lactobacillus mucilaginosus HG002 is as shown in SEQ ID NO: 1. The strain is separated from excrement of healthy adults, the relieving effect of ALF is remarkably improved through the brand-new fermentation lactobacillus mucus HG002 strain and derivative EVs thereof in combination with a synergistic effect mechanism and optimized product design, many defects in the prior art are overcome, and wide application prospects and industrialization value are achieved.

The invention relates to the technical field of microbiological detection and molecular biology, in particular to a specific detection primer for bifidobacterium longum subsp. Longum BBMN68 and application of the specific detection primer. The specific primer for detecting the bifidobacterium longum subsp.longum BBMN68, provided by the invention, comprises an upstream primer and a downstream primer, and nucleotide sequences are shown as SEQ ID NO.7-8. The invention also provides a kit for detecting the bifidobacterium longum subsp.longum BBMN68. The specific DNA fragment provided by the invention is a specific molecular marker of BBMN68, and the specific primer is designed aiming at the fragment sequence, so that the specific amplification of the strain can be realized, no cross reaction is caused to other related strains, the detection sensitivity is higher, and the detection requirements of samples with different concentrations can be met; the method can be used for specific detection and accurate quantification of the BBMN68 strain in yoghourt and other products, and has good practical application value.

The invention discloses a 5 'UTR library, a recombinant expression vector and a genetically engineered bacterium for improving the yield of folamin in pathogenic bacterium Badei and application of the 5' UTR library and the genetically engineered bacterium, and belongs to the technical field of microbial genetic engineering. The method comprises the following steps: designing an SD region based on a 16S rRNA (ribosomal Ribonucleic Acid) 3'end complementary sequence of a Buddei pathogenic bacterium XBD101 serving as an original strain, regulating and controlling the number of bases between the SD sequence and an initiation codon AUG and optimizing an UTR secondary structure to construct a library containing 14 UTR sequences, and replacing three sequences N4A, N7A and N18A with the strongest translation ability in the library to the UTR region of a folamin synthesis key gene fclC, so as to obtain the folamin peptide. And finally, the capacity upgrading of the folamin chassis strain is realized, and an important support is provided for the industrial production of agricultural antibiotics.

The application relates to the field of biotechnology, in particular to a Faecalibacterium prausnitzii microbial anti-inflammatory molecule and a screening method and application thereof. The amino acid sequence of the Faecalibacterium prausnitzii microbial anti-inflammatory molecule is shown in (a) or (b); (a) the amino acid sequence is shown in SEQ ID NO. 1; (b) a protein derived from (a) with anti-inflammatory activity obtained by substituting, deleting or adding one or more amino acids in the amino acid sequence in (a). Compared with the microbial anti-inflammatory molecule protein of a representative strain A2-165 of the Faecalibacterium genus, the inhibiting effects of the Faecalibacterium prausnitzii microbial anti-inflammatory molecule on the NF-kappa B signal pathway and the inflammatory factor TNF alpha are 50% and 56% respectively, and the anti-inflammatory effect (inhibiting the NF-kappa B signal pathway) of the Faecalibacterium prausnitzii microbial anti-inflammatory molecule screened in the application can reach more than 90%, and the Faecalibacterium prausnitzii microbial anti-inflammatory molecule has the advantages of small use dosage and strong anti-inflammatory effect.

The invention discloses a high-flux and rapid chromatin immunoprecipitation sequencing method based on a HiBiT tag and a Tn5 enzyme, and belongs to the technical field of biology. According to the method, the high affinity characteristic of a HiBiT tag system is combined with a Tn5 enzyme in-situ library building technology, firstly, a DNA binding protein recombinant expression strain containing a HiBiT tag is constructed and subjected to induced expression, after formaldehyde crosslinking and cell lysis, an Anti-HiBiT antibody is used for rapid immunoprecipitation, and a Tn5 enzyme library is constructed; tn5 transposase is directly loaded on the magnetic beads combined with the protein and DNA fragment compound to complete fragmentation and linker connection, so that the construction of a next-generation sequencing library is quickly carried out, and the total consumed time from immunoprecipitation to the completion of library construction is less than or equal to 5 hours. Meanwhile, automatic treatment is realized through a micro experiment board (the reaction system is less than or equal to 200 microliters) and a liquid workstation, the experiment cost and the sample dosage are reduced, 48 transcription factors and 48 control samples can be synchronously treated, the efficiency is greatly improved, and an efficient tool is provided for microbial transcription regulation and control research.

The invention discloses a mycobacteriophage and application thereof, and relates to the technical field of bacteriophages. The mycobacteriophage is named as Mycobacter phage BZNK001, is preserved in Guangdong Microbial Culture Collection Center, has a preservation number of GDMCC No: 67907-B1, does not contain antibiotic drug-resistant genes and integrase genes, has excellent biological safety and good environmental tolerance, can maintain high biological activity in a temperature range of 37-50 DEG C under an acid-base condition of pH 5-9, and can be used for preparing the antibiotic drug-resistant gene and integrase gene-containing mycobacteriophage for preventing and treating the antibiotic drug-resistant gene and integrase gene-containing mycobacteriophage for preventing and treating the antibiotic drug-resistant gene and integrase gene-containing mycobacteriophage. The bacillus subtilis has broad-spectrum and high-efficiency non-tuberculous mycobacterium cracking activity, and can effectively crack four clinical key mycobacteria such as mycobacterium abscessus, mycobacterium avium, mycobacterium intracellularis and mycobacterium smegmatis. According to the invention, a mycobacteriophage resource library is enriched, a novel and stable biological prevention and control means is provided for efficient prevention and control of mycobacteria, and the mycobacteriophage has good clinical application and industrialization values.

The invention relates to the technical field of molecular biology, and discloses a PCR (Polymerase Chain Reaction) chip and a kit for detecting the expression quantity of fluoride microbiological degradation related functional genes and application of the PCR chip and the kit. The PCR chip comprises a primer pair which is used for specifically amplifying a DeHa1 gene, a DehH2 gene, an Hddph gene and an alkB gene respectively, and a primer pair which is used for specifically amplifying the DeHa1 gene, the DehH2 gene, the Hddph gene and the alkB gene respectively, the nucleotide sequences of an upstream primer and a downstream primer of the primer pair for specifically amplifying the DeHa1 gene are as shown in SEQ ID NO.1-2; the nucleotide sequences of an upstream primer and a downstream primer of the primer pair for specifically amplifying the DehH2 gene are as shown in SEQ ID NO.3-4; the nucleotide sequences of an upstream primer and a downstream primer of the primer pair for specifically amplifying the Hddph gene are as shown in SEQ ID NO.5-6; the nucleotide sequences of an upstream primer and a downstream primer of the primer pair for specifically amplifying the alkB gene are shown in SEQ ID NO.7-8. The PCR chip can be used for accurately detecting the expression condition of fluoride microbiological degradation related functional genes through a qPCR technology, exploring the fluoride pollution bioremediation feasibility and evaluating the fluoride pollution bioremediation process.

The invention discloses bifidobacterium longum subsp. Infantis for regulating intestinal motility and aquaporin and application of the bifidobacterium longum subsp. Infantis, and belongs to the technical field of microorganisms. According to the invention, the bifidobacterium longum subsp. Infantis CCFM1269 is screened, and the bifidobacterium longum subsp. Infantis CCFM1269 has the effects of intestinal motility and aquaporin, specifically, the defecation frequency is reduced, and the water content of excrement and the small intestine propulsion rate are reduced. The intestinal motility abnormality is relieved by reducing the levels of neurotransmitters 5-HT, SP and VIP, and the intestinal moisture absorption and secretion are regulated by improving the mRNA expression of aquaporin AQP4 and AQP8. Meanwhile, the intestinal flora is adjusted by improving the diversity of the intestinal flora, and the content of propionic acid and butyric acid in excrement is increased.

The invention discloses a preparation method and application of athlete-derived bifidobacterium probiotics for intestinal barrier repair, and relates to the technical field of biochemistry and microorganisms, and the preparation method comprises the steps of special bacteria source sampling, directional separation and purification, molecular biological identification, antibiotic sensitivity evaluation and injury repair verification. According to the preparation method and application of the sportsman-derived bifidobacterium probiotics for repairing the intestinal barrier, the sportsman intestinal flora is used as an exclusive bacterial source, and the unique metabolic elite attribute and stress adaptability of the sportsman intestinal flora are utilized to directionally screen and obtain a bifidobacterium strain adaptive to an extreme physiological stress environment; the bottleneck that conventional probiotics are only suitable for a common physiological environment and the survival rate and activity in a stress state are greatly reduced is broken through, high survival rate and metabolic activity can be kept in extreme environments such as exercise heat stress and the like, and accurate repair of intestinal barriers is realized through multiple mechanisms; meanwhile, an exclusive screening, identification and safety evaluation system is established, so that the safety and functional specificity of the strain are ensured.

A microbial gene editing scheme automatic design method, system and storage medium; the method comprises: selecting a design object for different types of strains, the design object is bacteria or fungi; after determining the target gene, obtaining the target gene information from the NCBI database; the design scheme of bacteria comprises the following steps: determining the gRNA design region; selecting the optimal gRNA sequence; doing sequence complexity and GC content analysis; the design scheme of fungi uses a frameshift scheme: the gRNA of the frameshift scheme is set at any position not overlapping with other genes after the start codon in the gene; select gRNA sequence in gRNA design region, select the optimal gRNA sequence; design two pairs of four primer sequences for homologous arm identification primer; this scheme can replace the complicated and time-consuming manual scheme, save a lot of time, solve the problem of high cost in the design of the best site and the design of sgRNA sequence scheme of artificial gene knockout.

This invention relates to the fields of microbial genetic engineering and fermentation biomanufacturing technology, specifically disclosing a recombinant Corynebacterium glutamicum with high 5-aminolevulinic acid (ALA) production and its applications. Addressing the problems of existing strains such as crude enzyme activity regulation, inhibited cell growth, the need for external inhibitors, and low yield, this invention uses Corynebacterium glutamicum as a host and removes the gdhA gene without scarring to reduce precursor competitive metabolism. Site-directed mutations of the endogenous hemB gene (S288A, D128E, R231K) are performed to moderately reduce dehydratase activity. A high-expression plasmid pXMJ19-hemA containing the hemA gene from Rhodopsinus capsulatum is constructed and introduced into the modified strain to obtain a recombinant strain with optimized triple metabolism. This strain reduces product degradation without the need for external dehydratase inhibitors, does not affect cell growth, and achieves a yield up to 4.30 times higher than the control after 42 hours of fermentation, with ALA accumulation exceeding 8.9 g / L. The strain exhibits stable characteristics, the process is simple, and it has good industrial application value.

This invention proposes a molecular marker for *Lactobacillus japonicus*, which was deposited on February 7, 2023, at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 26505. The molecular marker comprises a nucleotide sequence selected from one of the following: (1) the nucleotide sequence shown in SEQ ID NO: 24; (2) a nucleotide sequence having at least 97%, 98%, 99%, or higher homology to the nucleotide sequence shown in SEQ ID NO: 24; or (3) a nucleotide sequence having one or more nucleotide substitutions, deletions, or insertions in the nucleotide sequence shown in SEQ ID NO: 24. Using the molecular marker of this invention, not only can the target *Lactobacillus japonicus* be screened quickly and easily, but it can also highly specifically identify the target *Lactobacillus japonicus*, eliminating interference from other strains.

The application provides a huperzine A-producing strain of the genus of giant priestleya, namely, the Sys-Hup-009 strain, the strain is preserved in the China Center for Type Culture Collection, the preservation date is October 31, 2025, the preservation number is CCTCC NO:M20252404, and the 16S rDNA sequence of the strain is shown as SEQ ID NO.1. The Sys-Hup-009 strain of the genus of giant priestleya provided in the application can metabolically produce huperzine A, can be subjected to large-scale fermentation culture in a short period, has low fermentation cost, is not limited by time domain, season and other conditions, and therefore can solve the problems of high cost, complicated steps and many intermediate pollutants in chemical synthesis of huperzine A through the microbial fermentation approach. Meanwhile, the application also provides optimized microbial fermentation conditions and a formula of a culture medium, and the yield of huperzine A is high.

The present application relates to the technical field of probiotics, and particularly relates to a Bifidobacterium breve strain and application of the Bifidobacterium breve strain in prevention or treatment of neurodegenerative diseases and neuroinflammation related to neurodegenerative diseases. Bifidobacterium breve ) BKR006, which is preserved in the China General Microbiological Culture Collection Center (CGMCC) (address: No. 1, Xili Beichen, Chaoyang District, Beijing), and the preservation number is CGMCC No. 36096. The strain in the present application is proved in animal experiments that the strain can not only significantly improve the cognitive function and A beta pathology of AD model animals, but also effectively inhibit neuroinflammation in PD models and improve related cognitive impairment, and has a broad spectrum of neuroprotective effect and good development and application prospect.

The present application relates to the application of Bifidobacterium longum subsp.longum BL21 in the preparation of a preparation for improving hematopoietic dysfunction, wherein the Bifidobacterium longum subsp.longum BL21 is a Bifidobacterium longum subsp.longum BL21 strain with a preservation number of CGMCC No.10452.The present application develops a new microbial strategy for improving hematopoietic dysfunction, and uses the Bifidobacterium longum subsp.longum BL21 in the preparation of a preparation for improving hematopoietic dysfunction.It is found that the Bifidobacterium longum subsp.longum BL21 can increase the number of peripheral blood cells (red blood cells and white blood cells), the content of platelets or the content of hemoglobin, reverse the weight loss caused by hematopoietic dysfunction, and improve the serum inflammatory response and the spleen inflammatory response caused by hematopoietic dysfunction.The present application also provides a new idea for the wide application of the Bifidobacterium longum subsp.longum BL21.

The invention relates to a method for improving the activity of a Meyerozyma guilliermonii ECH strain for producing ethyl carbamate hydrolase in the technical field of microorganisms, which comprises the following steps: inoculating a bacterial liquid containing the Meyerozyma guilliermonii ECH strain into a liquid fermentation culture medium according to the inoculum size of 10-18%, adjusting the initial pH value to 4-6, and culturing for 3-5 days at the temperature of 25-35 DEG C; the liquid fermentation culture medium contains ethyl carbamate. According to the method, the activity of the strain for producing the ethyl carbamate hydrolase can be remarkably improved.

The invention discloses an oxidation-resistant Exiguobacterium sp. LS01 from a marine environment, and belongs to the technical field of microorganisms. The bacterial strain is classified and named as Exiguobacterium oxytolerans, and is preserved in the China General Microbiological Culture Collection Center (CGMCC), and the preservation number is CGMCC No.36750. The invention further discloses a preparation method of the Exiguobacterium oxytolerans strain. The invention further discloses application of the strain and a microbial inoculum of the strain, the strain can stably generate extracellular xanthan gum hydrolase with remarkable xanthan gum degradation activity under the fermentation condition, the viscosity of xanthan gum can be effectively reduced, and a remarkable degradation effect on the xanthan gum is achieved. The strain, the microbial inoculum and the fermentation product thereof can be applied to the fields of xanthan gum degradation and related food, and have wide industrial application prospects.

The invention relates to the technical field of microorganisms, in particular to the technical field of agricultural microorganisms, and more particularly relates to a cellulose degradation composite flora as well as a construction method and application thereof. The cellulose degradation composite flora comprises a cellulose degradation bacterium, namely humid cellulomonas CW35 and an auxiliary strain used for digesting an intermediate metabolite of the humid cellulomonas CW35, and the auxiliary strain is one or more of pseudomonas Taiwan CW19, bacillus amyloliquefaciens L3 or microbacterium algal M266-2. Therefore, the feedback inhibition effect of a product in the cellulose degradation process of the cellulomonas can be destroyed, the expression and enzyme activity of cellulose degradation related genes are remarkably improved, and the decomposition utilization of cellulose-degrading bacteria, namely the wet cellulomonas CW35, on cellulose-containing wastes is effectively improved.

The invention provides a bacillus proteolyticus Sys-Gs-006 strain for producing ginsenoside Rh1, the strain is preserved in China Center for Type Culture Collection, the preservation date is December 9, 2025, and the preservation number is CCTCC NO: M20252815; the 16S rDNA (ribosomal deoxyribonucleic acid) sequence of the strain is as shown in SEQ ID NO. 1. The bacillus proteolyticus Sys-Gs-006 strain provided by the invention can produce ginsenoside Rh1 through metabolism, can be subjected to large-scale fermentation culture in a short time, is relatively low in fermentation cost, is not limited by conditions such as time domain and season, and has remarkable advantages. Meanwhile, the invention also provides optimized microbial fermentation conditions and a formula of the culture medium, and the yield of the ginsenoside Rh1 is relatively high.

The application discloses a gene editing system CRISPR-Cas12p and application thereof. Based on microbial genomes and metagenomic data, the CRISPR-Cas12p protein of the CRISPR-Cas protein family is obtained by preliminary screening by using a Prodigal gene prediction tool, a Pfam database and HMMER software, and a gene editing system CRISPR-Cas12p is constructed. PAM preference and interference function identification show that the editing system has a PAM preference of 5'-TTC-3', can effectively realize targeted cutting by using long transcripts and double RNA hybrid chain transcripts respectively, and can realize editing of a target gene in prokaryotic and eukaryotic cells. The CRISPR-Cas12p gene editing system obtained by the application has a small protein component, is beneficial to delivery, can realize gene editing in prokaryotic and eukaryotic cells, and has a wide application prospect.

This invention discloses a high-yield lactyl-3-4 ...5-4-4-4-4-4- N This invention relates to plasmid-free genetically engineered strains of tetrasaccharides and their applications, belonging to the field of microbial genetic engineering. The invention screened strains with higher activity. β -1,3-galactosyltransferase gene PmgalT Computer-aided enzyme function modification was used to achieve a shake-flask yield of 10.05 g / L for the constructed mutant. Subsequently, genome integration was performed... breast Multi-copy integration PmgalT * V27I / V39I / Y147F ‑galE‑galU A plasmid-free strain was constructed, enabling it to grow in shake flasks with lactoyl- N The yield of tetrasaccharides reached 14.4 g / L. Using glucose as the sole carbon source, the highest yield of 68.19 g / L was achieved at 64.5 h; using glycerol as the sole carbon source, the highest yield of 62.88 g / L was achieved at 60.5 h, providing a basis for its industrial production.

This invention discloses a methanogenic lyase homologous to PeiR lyase and its applications. The PeiR lyase protein, targeting the peptide bonds of the methanogenic cell wall, participates in the biological process of hydrolyzing the archaea cell wall, effectively killing methanogens and reducing methane production. Proteins homologous to this lyase possess potential methane-reducing potential. This invention utilizes a series of bioinformatics software to identify protein sequences encoded by methanogenic viruses from a large amount of rumen microbial virome sequencing data, and analyzes the structural homology between these proteins and PeiR. Ultimately, this invention successfully obtained a series of methanogenic lyases homologous to PeiR. To achieve the expression of these lyases, this invention designed multiple primers to synthesize the target sequences and successfully expressed them in a prokaryotic expression system. In vitro gas production experiments with the crude enzyme solution showed that these lyases are effective in reducing methane production.

This invention discloses the application of arginine-depleted engineered bacteria for the treatment of soft tissue sarcomas, including preliminary validation, obtaining qualified engineered bacteria SGR1, obtaining drug compositions and regimens, experimental conclusions, and clinical application promotion. During use, clinical soft tissue sarcoma samples are collected, including undifferentiated pleomorphic sarcoma, synovial sarcoma, and liposarcoma. Immunohistochemistry (IHC) is used to detect ASS1 protein expression, qPCR is used to detect ASS1 gene transcription levels, and the proportion of ASS1 deletion / low expression is statistically analyzed. Arginine auxotrophic sarcoma subpopulations are confirmed based on literature. Cells are cultured in arginine-containing or arginine-free media, and cell viability, colony formation, cell cycle, and apoptosis are detected. The sensitivity of ASS1-deficient cells to arginine deprivation is verified, and therapeutic targets are identified. The enzyme activity, substrate specificity, and immunogenicity of human ARG I / II, mycoplasma ADI, and Pseudomonas ADI are compared. High-activity, low-immunogenic enzymes or enzyme combinations (such as human ARG I + microbial ADI) are selected, and site-directed mutagenesis or codon optimization is performed on microbial ADI to increase expression levels.

The present disclosure relates, in general terms, to directed evolution, and more specifically to compositions and methods for phage-assisted directed evolution in microbes. In one embodiment, there is provided a method for directed molecular evolution, the method comprising: a) introducing a propagation-defective phage vector into a first host cell (mutagenic host) competent to propagate the phage vector, wherein the first host cell comprises a gene construct of interest (GOI) to be evolved; and wherein the phage vector allows for (i) expression of an error-prone DNA polymerase in the first host cell for mutagenesis, and (ii) replication and packaging of the GOI into infectious phage particles; b) incubating the first host cell under conditions for replication and mutagenesis of the GOI and release of phage particles comprising mutated GOIs; c) infecting a second host cell (selection host) with phage particles from step b); and d) selecting for a desirable function of the GOI in the second host cell.

The present application belongs to the field of genetic engineering and microbial fermentation technology, and particularly relates to a recombinant Escherichia coli for producing N-acetylglucosamine as well as a construction method and application thereof. The present application takes Escherichia coli as a chassis, knocks out the nagDCABE gene cluster, the manXYZ gene cluster and the serA gene of the genome of the Escherichia coli, and introduces the glmS, GNA1 and serA genes into the Escherichia coli through a vector for expression. The yield of the Escherichia coli for fermenting GlcNAc provided by the present application can reach more than 100 g / L.

Provided herein is a protein from Tumebacillus sp. NITE BP-02779 having a peptidoglycan-decomposing activity. Provided herein is a protein comprising the amino acid sequence of SEQ ID NO: 2 (1-164) or the amino acid sequence of SEQ ID NO: 4 (1-493), or a protein comprising an amino acid sequence in which 1 to 10 amino acid residues of these amino acid sequences are substituted, deleted, inserted, or added, or an amino acid sequence having 90% or more identity to these amino acid sequences, and having a peptidoglycan-decomposing activity.

The invention provides a glycosyl transferase gene for catalyzing astragalus smicus glycoside synthesis and application of the glycosyl transferase gene, and belongs to the technical field of biology. The invention develops a novel glycosyl transferase, a novel glycosyl transferase mutant is obtained by utilizing a genetic engineering method, and astragalus smicus glycoside can be synthesized through a microbial fermentation or in-vitro enzyme reaction process. The synthetic route is simpler, the synthetic condition is mild, the environmental pollution is small, the synthetic efficiency is higher, the purity is better, the waste of environmental resources is less, a new synthetic route is provided for the synthesis of the chemical substance, namely, the astragalin with high economic value, and a new thought and method are provided for actual production.

The invention relates to a Pseudomonas plecoglossicida pldB gene deletion mutant strain and a preparation method and application thereof, and belongs to the technical field of microorganisms and the field of algae preservation, the pldB gene of the mutant strain is deleted or inactivated, the nucleotide sequence of the pldB gene is shown as SEQ ID NO: 1, and the GenBank accession number of the Pseudomonas plecoglossicida is CP031146.1. The virulence of the mutant strain is obviously reduced compared with that of a wild strain of pseudomonas plecoglossicida; the strain can induce appropriate immune response of a host and up-regulate expression of anti-inflammatory factors, is beneficial to relieving immune pathological injury, has good attenuated live vaccine potential, and provides a brand new vaccine candidate strain for prevention and control of the visceral white-spot disease of the large yellow croaker.

The invention discloses a genetically engineered bacterium for producing D-pantothenic acid based on a corynebacterium glutamicum CPSPC system as well as a construction method and application of the genetically engineered bacterium. Wild type C.glutamicum ATCC 13032 is taken as a chassis strain, and a functional combination of a glycine ribosome switch BsGR from bacillus subtilis and a promoter Ptuf / Ph36 is verified through fluorescent protein mCherry; a GCS system of escherichia coli and bacillus subtilis is introduced to the strain DPAg-15, genes related to synthesis of 5, 10-dimethyltetrahydrofolic acid are tested, it is found that serA delta197GTG / ATG significantly increases the yield of D-pantothenic acid, the yield of D-pantothenic acid of the constructed strain DPAj-2-tuf is increased to 23.06 g / L (63 h), the yield is 0.37 g / L / h, and the conversion rate is 0.17 g / g; the engineering strain DPAj-2-tuf is obtained by dynamically regulating and controlling a D-pantothenic acid synthesis path through a CPSPC system and combining plasmid overexpression serA delta197GTG / ATG, the yield of the engineering strain DPAj-2-tuf is increased by 2.1 times compared with that of a traditional method, and an efficient technical scheme is provided for producing D-pantothenic acid through a microbial fermentation method.

The invention relates to a method for improving the gamma-aminobutyric acid yield of heterologous expression coffee GAD recombinant escherichia coli through ultrasonic and ultraviolet combined mutagenesis, and belongs to the technical field of microbial breeding. The method comprises the following steps: mutagenizing recombinant escherichia coli for heterologous expression of coffee-derived GAD by adopting an ultrasonic and ultraviolet sequential compound mutagenesis strategy, screening out bacterial colonies with good growth vigor through mutagenesis, finally inoculating the screened bacterial colonies into a fermentation culture medium for fermentation, and screening out bacterial strains with the highest GABA yield and conversion rate; the GABA yield of the mutagenized strain is improved by 31.3% compared with that of an initial strain, and the conversion rate is improved by 22.1%. The GABA yield, the GAD activity, the GAD gene expression quantity and the passage stability of the high-yield mutant strain UT-UV-3 are tested, the GABA yield, the conversion rate, the GAD activity and the GAD gene expression quantity of the high-yield mutant strain UT-UV-3 are remarkably improved, passage is stable, and the high-yield mutant strain UT-UV-3 has a good application prospect.