2246 results about "Glutamic acid" patented technology

The invention discloses a formate dehydrogenase mutant and application thereof in catalytic synthesis of D-mannitol, and belongs to the technical field of bioengineering. According to the formate dehydrogenase mutant provided by the invention, the 18th-site glutamic acid of wild-type formate dehydrogenase with an amino acid sequence shown as SEQ ID NO.2 is mutated into proline, the 57th-site asparagine is mutated into glutamic acid, the 70th-site histidine is mutated into tryptophan, the 235th-site serine is mutated into threonine, and the 316th-site valine is mutated into threonine, so that the formate dehydrogenase mutant is high in enzyme activity and catalytic activity; the coenzyme circulation efficiency during the production of D-mannitol can be obviously improved, so that the yield of D-mannitol can be effectively improved. When the genetically engineered bacterium co-expressed by the formate dehydrogenase mutant and the mannitol dehydrogenase mutant is used for catalyzing 150 g / L fructose to produce D-mannitol, the yield of D-mannitol within 15 h can reach 140 g / L or above.

The invention discloses a high-performance carbonyl reductase mutant and application thereof in synthesis of a series of chiral alcohols. The high-performance carbonyl reductase mutant is obtained by performing the following mutations on an amino acid sequence as shown in SEQ ID NO.2: the 69th alanine mutates into any one of lysine, leucine, aspartic acid or asparagine, and the 69th alanine mutates into any one of lysine, leucine, aspartic acid or asparagine; and / or the 100th glycine is mutated into any one of glutamic acid, serine, lysine or asparagine. Compared with a wild type enzyme, the thermal stability and the catalytic activity of the obtained mutant are remarkably improved, particularly, single point mutants Mut-A69N, Mut-G100E and Mut-G100N and a combined mutant Mut-A69N-G100N show excellent relative enzyme activity, thermal stability and substrate tolerance. The mutant has high catalytic activity and stability to various chiral alcohols, and the contradiction that the traditional carbonyl reductase is easy to inactivate at high temperature and the catalytic efficiency is difficult to achieve at the same time is solved. The invention provides an efficient and stable enzyme catalysis tool for green biological preparation of chiral drug intermediates.

The invention relates to the technical field of dye synthesis, and particularly discloses a genetically engineered bacterium for synthesizing N-acetyl blue as well as a construction method and application of the genetically engineered bacterium. The supply capacity of precursor substances glutamic acid and glutamine of the genetically engineered bacterium is high, the fermentation process is simple, the production intensity of the precursor substances glutamine and N-acetylglutamine is improved by cutting off a consumption path, relieving negative feedback inhibition and enhancing the expression level of key genes through the genetically engineered bacterium, and finally the yield of N-acetylblue reaches 41.2 g / L.

The invention relates to a composition comprising at least one oxidation coupler chosen from 6-hydroxybenzomorpholine of formula (I), one of its addition salts, its solvates and / or the solvates of its salts, at least one oxidation coupler chosen from 2-amino-5-ethylphenol of formula (II), one of its addition salts, its solvates and / or the solvates of its salts, and at least one compound chosen from N, N-dicarboxymethyl glutamic acid, one of its salts, and mixtures thereof. The invention also relates to a process for dyeing keratin fibres, preferably the hair, comprising the application of the composition to said keratin fibres.

The invention relates to a preparation method of antibacterial gamma-polyglutamic acid superabsorbent hydrogel. The preparation method comprises the following steps: (1) preparing a gamma-polyglutamic acid solution; (2) dissolving an antibacterial agent in the gamma-polyglutamic acid solution, and fully stirring and uniformly mixing to obtain a mixed solution 1; adjusting the pH value of the mixed solution 1, heating the mixed solution 1 to 60 DEG C, and continuously reacting for 1-2 hours to obtain a mixed solution 2; cooling the mixed solution 2 to room temperature, adding a cross-linking agent, and uniformly mixing to obtain a mixed solution 3; standing the mixed solution 3 at room temperature for 1-3 hours and then carrying out gradient heating reaction to obtain an antibacterial gelatinous product; and (3) dehydrating the antibacterial gelatinous product, and carrying out vacuum negative pressure drying to obtain a dried hydrogel product, namely the antibacterial gamma-polyglutamic acid super absorbent hydrogel. The antibacterial gamma-polyglutamic acid superabsorbent hydrogel prepared by the invention has good biocompatibility, is safe and non-toxic, also has excellent water absorption performance and antibacterial performance, and has a good application prospect.

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 present invention provides a phycocyanin-collagen composite hydrogel and its preparation method and application. The present invention utilizes transglutaminase to catalyze the combination of phycocyanin and collagen to form a new, more stable collagen; transglutaminase acts between protein molecules, utilizes lysine and glutamic acid in phycocyanin and collagen to transfer acyl groups, and cross-links to form new chemical bonds, thereby enhancing the binding strength of phycocyanin and collagen; the hydrogel prepared by the present invention can be used to prepare medical materials and combined with skin injury sites to solve the problem that traditional dressings are easy to adhere to wounds and easily penetrated by tissue fluid and become infected. In addition to ensuring basic air permeability, it reduces the adhesion of the dressing, increases moisture retention and antioxidant properties, and avoids secondary damage when replacing a new dressing. The hydrogel prepared by the present invention has a certain antioxidant capacity and can be used to prepare products with antioxidant effects.

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 application relates to an engineering bacterium for high yield of observation blue and a construction method and application thereof, and belongs to the technical field of biological synthesis of natural dyes. The engineering bacterium for high yield of observation blue expresses icd, bpsA, glnA Y405F and gdhA; the engineering bacterium knocks out acnR, yggB, glsK, aceA and ldh. By knocking out the yggB and aceA genes, performing site-directed mutation (Y405F) on the glnA gene, replacing the glsK gene with the glnA Y405F gene, replacing the acnR gene with the icd gene, replacing the ldh gene with the gdhA gene, and integrating the bpsA gene, the application can block the formation of by-products such as lactate and succinic acid in the observation blue synthesis process, improve the flow direction of the citric acid->isocitric acid->alpha-ketoglutaric acid->glutamic acid->glutamine path, and then improve the intracellular glutamine concentration, so that the yield of observation blue is improved.

The invention relates to a method for detecting activity of gamma-polyglutamic acid hydrolase and application. The method comprises the following steps: (1) preparing an enzymolysis reaction solution and a blank reaction solution; (2) preparing an NAC / OPA mixed solution; (3) adding an NAC / OPA mixed solution into the enzymatic hydrolysis reaction solution to obtain a reaction solution to be detected; (4) drawing a standard curve by taking L-glutamic acid as a standard substance; and (5) detecting the fluorescence intensity of the blank reaction solution and the reaction solution to be detected by using a microplate reader, and then calculating the activity of the gamma-polyglutamic acid hydrolase according to the fluorescence intensity and the standard curve. The method for detecting the activity of the gamma-polyglutamic acid hydrolase is high in detection speed, detection of a single sample can be completed within 25 min, and nearly real-time process monitoring is achieved. And the method has the advantages of reliable detection result and high accuracy, can be used for monitoring the enzyme activity of the gamma-polyglutamic acid hydrolase in the gamma-polyglutamic acid preparation process in real time and guiding the optimization of the fermentation process, and has extremely high industrial application value.

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 invention belongs to the technical field of petroleum fracturing production enhancement and modification, and specifically discloses a fracturing fluid pre-fluid for optimizing the size of in-situ autogenous proppant and its application, which is used to solve the problem of small particle size of proppant particles generated by hydrothermal reaction of formation minerals. The fracturing fluid pre-fluid is suitable for calcium-rich reservoirs and is composed of clean water, phosphate, pH regulator and Ca 2+ The chelating agent composition comprises 1 to 10 parts by weight of phosphate relative to 100 parts by weight of clean water, a volume molar concentration of the pH regulator is 1 to 5 mol / L, and Ca 2+ The molar concentration of the chelating agent is 0.001~1mol / L; the pH regulator is urea, ammonia, propionamide, etc. 2+ The chelating agent is EDTA, glutamic acid, etc. The present invention increases the average particle size of proppant particles generated by hydrothermal reaction of formation minerals, thereby improving the supporting effect thereof in micro-fractures of the formation.

The invention provides a lactobacillus plantarum MG360 with the efficacy of improving constipation, the preservation number of the lactobacillus plantarum MG360 is CGMCC NO 32953, and the lactobacillus plantarum MG360 is preserved in China General Microbiological Culture Collection Center on February 14, 2025. Meanwhile, the invention further provides a compound probiotic composition of the plant lactobacillus MG360 and the lactobacillus rhamnosus Eupro, the compound probiotic composition can be used for fermenting the coix seed enzymatic hydrolysate, and a fermentation product of the compound probiotic composition is rich in ferulic acid, vanillic acid, short-chain fatty acid, glutamic acid and the like. The fermentation product can obviously shorten the first black excrement discharge time of constipation mice, obviously improve the small intestine propulsion rate and the excrement water content, obviously improve the level of motility hormone (MTL, Gas, AchE, SP and 5-HT) in serum of the constipation mice and obviously reduce the level of inhibitory hormone (SS and VIP), and it is indicated that the fermentation product can relieve constipation by adjusting the gastrointestinal hormone peptide level. The preparation method of the probiotic preparation containing the plant lactobacillus MG360 and the compound probiotic fermentation preparation of the compound probiotic composition is simple, large-scale production can be achieved, and good application prospects are achieved.

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 environmental protection of bioremediation wastewater, and discloses an immobilized adsorption microsphere, which is prepared from Bacillus spp., Candida utilis and European nitrosomonas through an immobilized embedding technology. The microspheres provided by the invention can effectively repair glutamic acid high ammonia nitrogen fermentation wastewater.

The invention relates to the technical field of agricultural fertilizers, in particular to an organic-inorganic composite silicon-calcium-magnesium fertilizer and a preparation method and application of the organic-inorganic composite silicon-calcium-magnesium fertilizer. The high-temperature activated silicon-calcium-magnesium mineral powder is composed of calcined wollastonite powder, calcined serpentine powder, dolomite powder and zeolite powder; 2%-5% of an organosilane modifier, wherein the organosilane modifier is composed of gamma-aminopropyl triethoxy silane and gamma-glycidyl ether oxypropyl trimethoxy silane, and the organic silane modifier is composed of gamma-aminopropyl triethoxy silane and gamma-glycidyl ether oxypropyl trimethoxy silane; 18%-35% of a functional organic matter complex, wherein the functional organic matter complex is composed of mineral source sodium humate, bioactive small peptide, sodium alginate and polyglutamic acid; and 3%-8% of auxiliary functional components, so that the solubility and the bioavailability of silicon, calcium and magnesium elements in minerals are remarkably improved.

The invention provides p-hydroxymandelic acid synthetase, a gene, a mutant of the p-hydroxymandelic acid synthetase and application of the p-hydroxymandelic acid synthetase in asymmetric synthesis of (S)-mandelic acid. The p-hydroxymandelic acid synthetase disclosed by the invention is derived from actinomycetes Actinokineospora auranticola, the amino acid sequence of the p-hydroxymandelic acid synthetase is as shown in SEQ ID NO.1, and a mutant of the p-hydroxymandelic acid synthetase is obtained by performing single-point mutation or multi-point combined mutation on glutamic acid at the 187th site, isoleucine at the 189th site and threonine at the 211th site of the amino acid sequence as shown in SEQ ID NO.1. The p-hydroxymandelic acid synthetase and the mutant thereof can convert phenylpyruvic acid into (S)-mandelic acid with high optical purity, have the advantages of mild reaction conditions, simplicity and convenience in operation, safety, environment friendliness and the like, and have a very good industrial application prospect.

The invention discloses an oral instant film suitable for pet nutrition intervention and a preparation method of the oral instant film, and belongs to the technical field of pet oral preparations. The instant film adopts a sandwich type multi-layer structural design, sequentially comprises a first food calling layer, a core layer and a second food calling layer, can be selectively provided with a functional layer and an interface middle layer, and constructs a staggered hot-pressing laminated structure, so that the structural stability and the function delivery efficiency of a film body are remarkably improved. The core layer contains multiple composite active ingredients such as L-carnitine, coenzyme Q10, beta-glucan, glucosamine sulfate and the like, chitosan-inulin-polyglutamic acid or starch is adopted for embedding to form a first microcapsule and a second microcapsule, and intelligent delivery of temperature / pH response and gastrointestinal controlled release is achieved. The food calling layer is composed of chicken powder, fish oil powder, fructo-oligosaccharide and the like, and the feeding compliance of pets is improved.

The invention belongs to the technical field of petroleum fracturing yield increase transformation, and particularly discloses fracturing fluid prepad fluid for optimizing the size of an in-situ authigenic proppant and application of the fracturing fluid prepad fluid, which are used for solving the problem of small particle size of proppant particles generated by a formation mineral hydrothermal reaction in the prior art. The fracturing fluid prepad fluid is suitable for a calcium-rich reservoir and is composed of clear water, phosphate, a pH regulator and a Ca < 2 + > chelating agent, relative to 100 parts by weight of clear water, the content of the phosphate is 1-10 parts by weight, the volume molar concentration of the pH regulator is 1-5 mol / L, and the volume molar concentration of the Ca < 2 + > chelating agent is 0.001-1 mol / L; the pH regulator is urea, ammonia water, propanamide and the like, and the Ca < 2 + > chelating agent is EDTA (Ethylene Diamine Tetraacetic Acid), glutamic acid and the like. The average particle size of the proppant particles generated by the formation mineral hydrothermal reaction is increased, and the supporting effect of the proppant particles in formation microfractures is improved.

The invention belongs to the field of medicines, and discloses application of pyroglutamic acid in preparation of products for inhibiting fat deposition. The invention has the following advantages: 1, obesity induced by high fat diet is prevented; 2, pyroglutamic acid is a natural amino acid derivative, widely exists in animal and plant bodies, and has good biological safety; meanwhile, the invention further discloses a product for inhibiting fat deposition.

The invention belongs to the technical field of soil organic matter improvers, and discloses a soil organic matter improver based on a compound microbial agent and a preparation method thereof, and the soil organic matter improver comprises the following components: a compound enzyme, a modified chitosan microsphere complex, a modified polyelectrolyte, an inhibitor L-methionine sulfoximine, a substrate, an auxiliary factor and the compound microbial agent. A compound enzyme system is used as a core, soil ammonium ions are circularly and efficiently assimilated through glutamine synthetase / glutamate synthetase, and the soil ammonium ions are converted into organic nitrogen; and energy guarantee is provided by virtue of polyphosphate kinase. The modified chitosan microsphere complex is used for protecting and slowly releasing enzyme and a substrate, and controlled release of the inhibitor L-methionine sulfoximine is realized through the modified polyelectrolyte, so that carbon-nitrogen balance of soil is regulated and controlled. The system has a synergistic effect with a compound microbial agent, the problem of soil organic matter reduction caused by excessive nitrogen application is effectively solved, meanwhile, the crop root biomass is remarkably increased, and the soil organic matter content is increased.

The invention belongs to the technical field of aquatic product living body transportation, and particularly relates to a soft-shell crab transportation method. The method comprises the following steps: screening and cleaning, softening-keeping treatment, fresh-keeping treatment, microenvironment regulation and treatment after transportation. In the softening treatment, 0.1-3 PSU low-salt seawater containing 0.03%-0.08% of tetrasodium glutamate diacetate is used for soaking / covering, the fresh keeping is ethanol disinfection and 0.05%-0.30% of lemon grass oil emulsified spray, the temperature of the microenvironment is controlled to be 12-18 DEG C, the humidity is 85%-95%, and the oxygen content is 20.90-22.30%. After 72 hours of simulated transportation, the softness-keeping maintenance rate is greater than or equal to 88%, the survival rate is greater than or equal to 98%, the body surface bacterial colony inhibition rate is 91.4%, and the TVB-N value is 15.2 mg / 100g. The method realizes the synergy of softening, fresh keeping and live keeping, is suitable for large-scale transportation, and has high popularization value.

This disclosure describes methods for improving umami and meaty flavors of cell-based food products. In particular, the disclosed method includes an amino acid integration method where cultured cells and exogenous amino acids (e.g., glutamic acid and aspartic acid) are combined and heated, resulting in a synergistic improvement of umami flavors. The disclosed method further includes a browning method by which a cell suspension is dehydrated and heated at high temperatures (e.g., greater than 140C) to induce non-enzymatic browning and caramelization reactions in the cell suspension. The cell-based flavoring product can be combined with a food product as a flavor, aroma, and color enhancer. The disclosed methods may use one or both of the amino acid integration method and the browning method to improve organoleptic properties of cell-based food products.

The invention provides a plasmid, an alpha-ketoglutaric acid engineering strain and a construction method and application of the alpha-ketoglutaric acid engineering strain, the strain is obtained by adopting a directional transformation method, transcriptional levels of katE, katG, sodB and grxA genes are up-regulated, a catR gene and a katA gene are heterologously expressed, a high-copy plasmid pETKG is carried, and the plasmid simultaneously expresses L-glutamate oxidase LGOX genes from Streptomyces sp and Chain A; the strain self-synthesized catalase eliminates H2O2 generated in the process of producing alpha-ketoglutaric acid through enzyme catalysis, engineering bacteria of L-glutamate oxidase LGOX expressed by pETKG plasmids are used for performing whole-cell catalysis on L-sodium glutamate to synthesize alpha-ketoglutaric acid, and the engineering strain is a high-level engineering strain capable of industrially and stably producing alpha-ketoglutaric acid.

The invention provides a low-molecular soluble chelating collector as well as a preparation method and application thereof, and belongs to the technical field of mineral processing. According to the collecting agent, low-molecular-weight ethylene glycol terephthalate serves as a precursor, and isosorbide is introduced for a copolymerization reaction; glutamic acid is introduced as a branched chain unit, and the branching degree and reaction active site density of the molecular structure are remarkably improved by utilizing the polyfunctional group characteristic of glutamic acid. A rigid ring structure and an ether bond of the isosorbide endow the medicament with good water solubility and dispersity, and invalid curling of a macromolecular chain is avoided; the introduction of glutamic acid branched chains greatly increases the number of hydroxyl groups and amino groups capable of reacting with carbon disulfide, so that each molecule carries more xanthate groups, and the adsorption stability and coverage density of the molecule on the surface of arsenopyrite are enhanced. By means of the structure, xanthate functional groups are fully exposed, multi-tooth chelation is easily conducted on the xanthate functional groups and iron and arsenic ions on the surface of arsenopyrite, a strong hydrophobic surface layer is formed, and therefore the collecting selectivity is remarkably improved.

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.