962 results about "Valine" patented technology

The invention relates to a fluorescent protein selection marker staygold-levEr gene as well as a construction method and application thereof, and belongs to the technical field of biological engineering. The invention provides a fluorescent protein selection marker staygold-levEr gene for screening an L-valine production strain and a construction method of a gene fragment, compared with other similar gene selection markers, the selection marker provided by the invention has the advantages that the fluorescence intensity is positively correlated with the concentration of L-valine, and the screening marker has the advantages that the screening marker can be used for screening the L-valine production strain; according to the screening marker, the screening efficiency of the L-valine high-yield strain can be obviously improved, the screening time and cost can be saved, the screening efficiency can be improved, and the screening marker has a wide application prospect.

The invention relates to the technical field of microbial fermentation, and discloses a genetically engineered bacterium of high-yield D-pantothenic acid as well as a preparation method and application of the genetically engineered bacterium. The D-PA yield of the engineering bacteria is greatly improved through the following effects that acetolactate synthase IlvB and IlvN shunted by pyruvic acid are subjected to overexpression, meanwhile, a transcription attenuation region is deleted, and valine feedback inhibition sites are mutated; the method comprises the following steps: overexpressing keto-alcohol acid reductoisomerase IlvC and dihydroxy acid dehydratase IlvD, and converting the IlvC coenzyme preference from NADPH into NADH, so as to break through the upstream of D-PA synthesis; overexpression of PanB is carried out, overexpression of a serine-glycine transport system is carried out, and synthesis of 5, 10-methylenetetrahydrofolic acid is promoted; meanwhile, the expression of ketopantoic acid reductase PanE is enhanced; and finally, over-expressing pantothenic acid synthetase PanC, and increasing the content of a cofactor ATP required by the PanC. According to the engineering bacteria provided by the invention, through overall reinforcement of the multiple modules, cell growth is improved due to balance of cofactors and increase of D-PA, and the yield of D-PA reaches an unprecedented height.

The invention discloses recombinant escherichia coli for inactivating or weakly expressing SPMB family inner membrane protein and application of the recombinant escherichia coli in production of L-amino acid. The invention relates to the technical field of gene engineering, and provides recombinant escherichia coli, and SPMB family inner membrane protein in the recombinant escherichia coli is inactivated or reduced in activity. According to the invention, the yjiG gene (coding gene of SPMB family inner membrane protein) in escherichia coli is knocked out, so that the expression intensity of the yjiG gene is weakened, and fermentation production strains of L-threonine, L-tryptophan, L-arginine and L-valine, which are more cost-effective, can be produced. The invention has important significance for improving the fermentation yield of bacteria, namely L-threonine, L-tryptophan, L-arginine and L-valine.

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 provides a fluorescent protein selection marker staygold-ygjHr gene and application thereof, and belongs to the technical field of biological engineering. The preparation method comprises the following steps: replacing codons of L-valine in nucleotide sequences of a fluorescent protein gene Staygold and a gene ygjH by using a rare codon GTC to respectively obtain a fluorescent protein gene Staygoldr after codon replacement and a gene ygjHr after codon replacement, and connecting the two segments of genes after codon replacement by using a flexible protein peptide to obtain the fluorescent protein selection marker Staygold-ygjHr gene. Experiments prove that the gene can obviously improve the screening efficiency of L-valine high-yield strains.

The invention provides a keto-alcohol acid reductoisomerase mutant and application of the keto-alcohol acid reductoisomerase mutant in construction of genetically engineered bacteria for high yield of D-pantothenic acid. In order to solve the technical problem that in the prior art, the yield of D-pantothenic acid synthesized through microbial fermentation is not high, semi-rational design of enzyme is adopted, and a keto-alcohol acid reductoisomerase mutant with substrate specificity is obtained and applied to construction of genetically engineered bacteria for high yield of D-pantothenic acid. According to the invention, a genetically engineered bacterium with high yield of D-pantothenic acid is constructed by utilizing the keto-alcohol acid reductoisomerase mutant through a CRISPR-Cas9 gene editing technology, so that the yield of D-pantothenic acid is increased by about 12.04%, and compared with an original strain, the valine accumulation amount in obtained fermentation liquor is almost unchanged compared with that of a control, and the yield of D-pantothenic acid is greatly improved. However, the accumulation of branched chain amino acid isoleucine is less, so that the modification of the substrate specificity of the keto-alcohol acid reductoisomerase is achieved.

The invention relates to the technical field of gene engineering and enzyme engineering, in particular to an esterase mutant for degrading ethyl carbamate and application of the esterase mutant, the esterase mutant has an amino acid sequence as shown in SEQ ID NO.1 which is subjected to site mutation, the site mutation is any one or more site combined mutation of V129S, V161L or I229M, and the amino acid sequence of the esterase mutant is shown in SEQ ID NO.1. The V129S site mutation is that valine at the 129 site is mutated into serine, the V161L site mutation is that valine at the 161 site is mutated into leucine, and the I229M site mutation is that isoleucine at the 229 site is mutated into methionine. Mutation is carried out through a site-directed mutagenesis method, so that the amino acid sequence of the esterase mutant V129S / I229M is changed, the autoplasmic structure and function of eggs are changed, the esterase mutant V129S / I229M with the ethyl carbamate hydrolysis rate increased to 6.55 times in an acid environment is finally obtained, and the esterase mutant V129S / I229M has high industrial application value.

VH domain, in which: (i) the amino acid residue at position 1 12 is one of K or Q; and / or (ii) the amino acid residue at position 89 is T; and / or (iii) the amino acid residue at position 89 is L and the amino acid residue at position 1 10 is one of K or Q; and (iv) in each of cases (i) to (hi), the amino acid at position 1 1 is preferably V; and in which said VH domain contains a C-terminal extension (X)n, in which n is 1 to 10, preferably 1 to 5, such as 1, 2, 3, 4 or 5 (and preferably 1 or 2, such as 1); and each X is an (preferably naturally occurring) amino acid residue that is independently chosen, and preferably independently chosen from the group consisting of alanine (A), glycine (G), valine (V), leucine (L) or isoleucine (I).

The invention discloses a cyclic nonapeptide with repairing and anti-oxidation effects and application of the cyclic nonapeptide, the amino acid sequence of the cyclic nonapeptide is cyclic (arginine-glycine-aspartic acid-serine-arginine-lysine-valine-lysine-serine), the prepared cyclic nonapeptide has the repairing and anti-oxidation effects, and the cyclic nonapeptide has the repairing and anti-oxidation effects. The composition can be applied to preparation of cosmetics with repairing and / or anti-oxidation effects.

The invention discloses a hydrogel patch for gastric perforation repair and a preparation method thereof, and belongs to the technical field of biomedical materials. The preparation method comprises the following steps: dissolving acryloyl valine, acrylic acid, methylene bisacrylamide, a compound A and a photoinitiator in an alcohol solvent, and defoaming to obtain a precursor solution; and placing the precursor solution in a mold, carrying out ultraviolet-induced curing, soaking the obtained hydrogel in a hydrochloric acid solution, and replacing the alcohol solvent to obtain the hydrogel patch for gastric perforation repair. The hydrogel patch provided by the invention has the advantages of strong acid corrosion resistance, good biocompatibility, low swelling ratio, stable adhesion performance in a fluctuating pH environment and the like. The tough and stable adhesion performance ensures that the hydrogel can be permanently and reliably adhered to a gastric perforation part in a dynamic gastric acid environment, and a stable platform is provided for drug delivery, so that the surgical operation time is expected to be shortened, and wound healing is promoted.

Composition for use in the prevention and / or treatment of a liver disease in a mammal, the composition comprising an active agent, said active agent containing the amino acids leucine, isoleucine, valine, threonine, lysine and the carboxylic acids citric acid, succinic acid, malic acid.

The invention relates to an L-valine production strain as well as a construction method and application thereof, the strain is obtained by transformation through a metabolic synthesis path of L-valine, and the construction method comprises the following steps: by taking Cornebacterium glutamicum ATCC 13032 (C.glutamicum) as an original strain, carrying out editing transformation such as gene knockout, gene overexpression, gene heterologous expression, gene double-copy expression and the like on a genome of the original strain by utilizing a metabolic engineering means. The L-valine production strain disclosed by the invention can be used for synthesizing L-valine from the beginning by taking glucose as a carbon source, has the advantages of high production rate, short fermentation period, high strain stability and low cost, and lays a foundation for realizing large-scale production of L-valine. According to the fermentation tank fermentation method, the L-valine is produced in a mechanical stirring type fermentation tank by using the L-valine production strain Va1-09, 86.4 g / L of L-valine is produced by fermenting for 36 hours, and the method has a good industrial prospect.

The invention relates to the technical field of biological catalysis, and discloses an M88V mutant enzyme for preparing rebaudioside I. The M88V mutant enzyme is obtained by the following mutations generated by UGT76G1: M88V: methionine of the 88th amino acid sequence of UGT76G1 is mutated into valine. Aiming at the technical bottlenecks of low RI yield and poor selectivity in the existing RA biotransformation process, an efficient solution is provided for the UGT76G1 mutant developed by the invention. The mutant can specifically catalyze conversion from RA to RI, and the conversion rate of a target product is remarkably increased to 65% or above from general less than 7%. The excellent catalytic performance of the catalyst is verified in milliliter-level to upgraded reaction systems, the key problems of conversion efficiency and process amplification are solved, and a foundation is laid for large-scale green manufacturing of a high-added-value product RI.

The invention provides a branched chain amino acid transaminase gene and application thereof, and belongs to the field of gene engineering. According to the invention, the branched chain amino acid transaminase gene HvBCAT5 is found for the first time, and the gene has obvious positive correlation with the accumulation of valine (Val), isoleucine (Ile) and leucine (Leu) of crops. The invention provides an important target gene HvBCAT5 for crop quality improvement, and has important value for increasing the content of branched chain amino acid of crops and improving dietary nutrition. The HvBCAT5 gene as well as a recombinant vector, a recombinant bacterium and a transgenic plant thereof have good application prospects in the fields of food and feed industry.

The invention provides a keto-alcohol acid reductoisomerase mutant and application of the keto-alcohol acid reductoisomerase mutant in construction of genetically engineered bacteria for high yield of D-pantothenic acid. In order to solve the technical problem that in the prior art, the yield of D-pantothenic acid synthesized through microbial fermentation is not high, semi-rational design of enzyme is adopted, and a keto-alcohol acid reductoisomerase mutant with substrate specificity is obtained and applied to construction of genetically engineered bacteria for high yield of D-pantothenic acid. According to the invention, a genetically engineered bacterium with high yield of D-pantothenic acid is constructed by utilizing the keto-alcohol acid reductoisomerase mutant through a CRISPR-Cas9 gene editing technology, so that the yield of D-pantothenic acid is increased by about 12.04%, and compared with an original strain, the valine accumulation amount in obtained fermentation liquor is almost unchanged compared with that of a control, and the yield of D-pantothenic acid is greatly improved. However, the accumulation of branched chain amino acid isoleucine is less, so that the modification of the substrate specificity of the keto-alcohol acid reductoisomerase is achieved.

The present application relates to ketol reductoisomerase variants, polynucleotides encoding the variants of the present disclosure, L-valine-producing microorganisms comprising the ketol reductoisomerase variants of the present disclosure or the polynucleotides encoding the variants, and methods of producing L-valine using the microorganisms of the present disclosure.

The invention relates to the technical field of biology, and discloses a carbonyl reductase mutant and application thereof in enzymatic synthesis of chiral alcohol. The amino acid sequence as shown in SEQ ID NO.2 is subjected to mutation that 36th lysine is mutated into any one of aspartic acid, threonine and valine, or / and 125th histidine is mutated into any one of lysine, serine and leucine, or 170th histidine is mutated into any one of lysine, cysteine and leucine. The carbonyl reductase mutants, especially single-site mutants Mut-T75K, Mut-T75D and Mut-E216M and a combined mutant Mut-T75K-E216M, with activity improved to different extents compared with that of a wild type are obtained, have excellent relative enzyme activity, thermal stability and substrate tolerance, have relatively high activity and stability for various chiral alcohols, and can be used for preparing the carbonyl reductase mutants. The catalyst has the advantages of high catalytic activity, high thermal stability, strong substrate tolerance, easiness in fermentation and the like.

The invention discloses application of synbiotics to prevention and control of plutella xylostella pests. Probiotics in the synbiotics are a pseudomonas strain PPF1, the pseudomonas strain PPF1 is classified and named as Pseudomonas putida, and the prebiotic composition is ornithine, alanine, valine, serine, leucine and cycloleucine. The invention further discloses a preparation method of the prebiotic composition. Wherein the pseudomonas can improve the resistance of Chinese cabbage to plutella xylostella. According to the prebiotic composition, the resistance of Chinese cabbage to plutella xylostella is improved, meanwhile, the growth of the pseudomonas strain PPF1 is remarkably promoted, and the colonization ability of the pseudomonas strain PPF1 is improved. The synbiotics are applied into soil by a root irrigation method, so that the feeding area of the cabbage by the plutella xylostella can be remarkably reduced, and the pest of the plutella xylostella in the cabbage can be effectively prevented and controlled.

The invention discloses intestinal bacteria and serum metabolites which can be used as biomarkers of type 2 diabetes mellitus (prediabetes mellitus (PDM), new diagnosis diabetes mellitus (NDDM) and diabetes mellitus (P2DM) after medication) in different disease stages, and application of the intestinal bacteria and the serum metabolites. Aiming at type 2 diabetes mellitus, predictive markers including staphylococcus aureus, escherichia coli, klebsiella pneumoniae, branched chain amino acids (leucine, valine and isoleucine) and the like, especially staphylococcus aureus of which the genome contains acetolactate synthase (ALS), are efficiently screened out. The type 2 diabetes mellitus marker disclosed by the invention can be used for early warning the illness risk of type 2 diabetes mellitus and guiding the adjustment of an intestinal microbial environment; the method can be used for indicating the correlation between the intestinal microbial environment and the type 2 diabetes mellitus and is used for assisting diagnosis; and drug action target research, accurate medication, pathogenesis research and the like are realized.

The invention belongs to the technical field of microbial fermentation, and discloses torulopsis variabilis and application thereof. Wild torulopsis variabilis is separated from soy sauce mash, a strain of torulopsis variabilis with high yield of aspartic acid, threonine, glutamic acid, valine, methionine, isoleucine, leucine and lysine is obtained through ARTP mutagenesis, the collection number of the torulopsis variabilis ZB444 is GDMCC No: 65240, the classification name of the Latin name of the torulopsis variabilis is Wickhamiella versitis, the collection number of the torulopsis variabilis ZB444 is CGMCC No: 65240, and the collection number of the torulopsis variabilis ZB444 is CGMCC No: 65240. The strain is preserved in Guangdong Microbial Culture Collection Center on October 12, 2024. The strain is applied to soy sauce fermentation, the content of various amino acids and the content of total amino acids in soy sauce can be increased, the nutritional value of the soy sauce can be increased, and meanwhile the flavor of the soy sauce is enhanced.

The present invention discloses a pectin methylesterase mutant ΔDdPemA, its encoding gene, preparation method, and application. The pectin methylesterase mutant ΔDdPemA is obtained by mutating the amino acid at position 200 in the center of the substrate binding pocket of the wild-type pectin methylesterase DdPemA from a high-molecular-weight, branched valine to a low-molecular-weight alanine, and by mutating the amino acid at position 339 at the substrate inlet and outlet of the substrate binding pocket from a high-molecular-weight, branched valine to a basic lysine. The amino acid sequence and nucleotide sequence of the wild-type pectin methylesterase DdPemA are SEQ ID NO. 1 and SEQ ID NO. 2, respectively. The mutant enzyme provided by the present invention has significantly improved enzyme activity under weakly acidic conditions, solving the problem of insufficient catalytic activity of the wild-type pectin methylesterase under weakly acidic conditions and creating favorable conditions for the application of the enzyme in the fields of food, textiles, and feed processing.

Disclosed are isolated or purified T cell receptors (TCRs), wherein the TCR has antigenic specificity for a mutated human RAS amino acid sequence with a substitution of glycine at position 12 with aspartic acid, valine, or arginine. Related polypeptides and proteins, as well as related nucleic acids, recombinant expression vectors, host cells, populations of cells, and pharmaceutical compositions are also provided. Also disclosed are methods of detecting the presence of cancer in a mammal and methods of treating or preventing cancer in a mammal.

The invention relates to the technical field of information, and discloses a method for predicting the optimal branched chain amino acid ratio of daily ration of lactating sows, which comprises the following steps of: 1, acquiring production data and feed formula data; 2, processing the production data and the feed formula data to obtain production sample data and formula sample data; 3, performing correlation calculation on the production sample data and the formula sample data to obtain most effective features and calculate feature vectors; 4, training a preset model according to the feature vector and the formula sample data; 5, verifying the preset model, and selecting an optimal prediction model according to an evaluation result; and 6, outputting an isoleucine content prediction value, a leucine content prediction value and a valine content prediction value by the optimal prediction model. The prediction method can accurately and reliably predict the branched chain amino acid proportion of daily ration with different protein levels. Meanwhile, the invention further provides a prediction device for the optimal branched chain amino acid proportion of the daily ration of the lactating sow.

The invention belongs to the technical field of biology, and particularly relates to antibacterial peptide based on large yellow croaker CXCL8 protein and application of the antibacterial peptide. The preparation method comprises the following steps: by taking a large yellow croaker CXCL8 protein as a template, intercepting a linear polypeptide of 13 amino acids, and carrying out carboxyl terminal amidation modification, so as to obtain the antibacterial peptide AVV13N, and the amino acid sequence of the antibacterial peptide AVV13N is Ala-Arg-Trp-Val-Arg-Arg-Val-Leu-Lys-Lys-Met-Val-NH2; the antibacterial peptide AVK13N is obtained by interchanging lysine at the 11th site and valine at the 13th site in an amino acid sequence of the antibacterial peptide AVV13N, and the amino acid sequence of the antibacterial peptide AVK13N is Ala-Arg-Trp-Val-Arg-Arg-Val-Leu-Lys-Lys-Val-Met-Lys-NH2. The molecular weights of the antibacterial peptides AVV13N and AVK13N are both 1669.12 Da, the isoelectric points of the antibacterial peptides AVV13N and AVK13N are both 12.44, and the antibacterial peptides AVV13N and AVK13N are both alkaline polypeptides. The antibacterial peptides AVV13N and AVK13N have broad-spectrum bactericidal activity and can be used for specifically killing gram-positive bacteria and gram-negative bacteria. In addition, the antibacterial peptides AVV13N and AVK13N have relatively weak hemolytic activity, relatively low cytotoxicity and good temperature stability, pH value stability and salt ion stability. The antibacterial peptides AVV13N and AVK13N provided by the invention can replace antibiotics and are applied to prevention and treatment of bacterial diseases.

The invention relates to a mutant based on cytochrome P450BM3 and application of the mutant in chloroaniline biodegradation, and belongs to the field of enzymology. The mutant is obtained by mutating threonine at the 268 site of an amino acid sequence shown in SEQ ID NO.1 into aspartic acid or glutamic acid, mutating alanine at the 328 site into phenylalanine, and mutating alanine at the 328 site into phenylalanine. According to the present invention, the amino acid at the 87 site is mutated into alanine, and the valine at the 78 site is mutated into alanine, such that a variety of mutants such as T268D / A328F, T268E / A328F, T268D / A328F / F87A, T268E / A328F / F87A, T268D / A328F / F87A / V78A and T268E / A328F / F87A / V78A are obtained; according to the present invention, the degradation rate of the mutant on 4-chloroaniline, 2-chloroaniline, 2, 4-dichloroaniline, 3, 4-dichloroaniline and 3, 5-dichloroaniline is achieved; the method has important significance and application value for promoting rapid degradation of chloroaniline pollutants in a water environment and maintaining ecological balance.

The invention discloses escherichia coli recombinant bacteria with high glycolic acid yield and a construction method of the escherichia coli recombinant bacteria, and belongs to the technical field of bioengineering. Lactate dehydrogenase ldhA, phosphate transacetylase pta, acetokinase ackA and pyruvate oxidase poxB are knocked out in escherichia coli, key enzymes isocitrate lyase aceA and glyoxylate reductase ghrA in a glycollic acid synthesis path are over-expressed in a genome level, conversion of carbon flow to glycollic acid is enhanced, and the glycolic acid is converted into glycolic acid. On the basis, malic acid synthase AaceB, malic acid synthase GglcB and glycollic acid oxidase glcDEF are knocked out, a branch metabolic pathway is blocked, an efficient strain which is free of plasmids and resistance genes and does not need to induce glycollic acid production is constructed, the accumulation amount of L-valine fermented in a 5L fermentation tank for 48 hours reaches 51.2 g / L, the yield is 0.6 g / g, and the production intensity is 1.06 g / L / h.

The invention discloses a gelator and a preparation method and application thereof, the structural formula of the gelator is # imgabs0 #, R1 is a side chain group connected to an amino acid central carbon atom except an amino group, a carboxyl group and a hydrogen atom; the amino acid is selected from one of glycine, alanine, valine, leucine, isoleucine, methionine, proline, tryptophan, serine, tyrosine, cysteine, phenylalanine, asparagine, glutamine, threonine, aspartic acid, glutamic acid, lysine, arginine, histidine, selenocysteine and pyrrole lysine; the amino acid is selected from one of glycine, alanine, valine, leucine, isoleucine, methionine, proline, tryptophan, serine, tyrosine, cysteine, phenylalanine, asparagine, glutamine, threonine, aspartic acid, glutamic acid, lysine, arginine, histidine, selenocysteine and pyrrole lysine; r2 is alkyl with the carbon atom number of 16 to 19; and R3 is 9-fluorenyl methoxy carbonyl group or t-butyloxycarbonyl group. The gelator has a hydrophobic long alkyl tail chain, can spontaneously gather and assemble into a three-dimensional network structure through hydrogen bonds, pi-pi interaction and hydrophobic force, and fixes an oil phase in an oil solvent or an oil-water mixture in an effective manner to form high-strength gel.

The invention provides a keto-alcohol acid reductoisomerase mutant and application of the keto-alcohol acid reductoisomerase mutant in construction of genetically engineered bacteria for high yield of D-pantothenic acid. In order to solve the technical problem that in the prior art, the yield of D-pantothenic acid synthesized through microbial fermentation is not high, semi-rational design of enzyme is adopted, and a keto-alcohol acid reductoisomerase mutant with substrate specificity is obtained and applied to construction of genetically engineered bacteria for high yield of D-pantothenic acid. According to the invention, a genetically engineered bacterium with high yield of D-pantothenic acid is constructed by utilizing the keto-alcohol acid reductoisomerase mutant through a CRISPR-Cas9 gene editing technology, so that the yield of D-pantothenic acid is increased by about 12.04%, and compared with an original strain, the valine accumulation amount in obtained fermentation liquor is almost unchanged compared with that of a control, and the yield of D-pantothenic acid is greatly improved. However, the accumulation of branched chain amino acid isoleucine is less, so that the modification of the substrate specificity of the keto-alcohol acid reductoisomerase is achieved.

The invention discloses a preparation method for preparing a biological fertilizer by using valine fermentation liquor, and relates to the technical field of biological fertilizer preparation, and the preparation method has the advantages that large-particle impurities and suspended solids are effectively removed by pretreating the valine fermentation liquor and using a ceramic microfiltration membrane, so that a foundation is laid for subsequent purification; then, a special adsorption material is adopted, mesoporous silica is used as a basis, after amino functional groups are introduced through surface modification, the chemical property of the adsorption material is changed, the affinity to valine is enhanced, a polymerization reaction is performed under the action of an initiator to form a polymer network, then the template molecule valine is removed, and the adsorption material is prepared. According to the present invention, the high-purity valine solution is added to the valine solution, such that the identification site complementary to the shape, the size and the chemical function of the valine is left, the valine can be accurately identified and adsorbed, the separation purification effect of the valine is substantially improved, and the accuracy and the stability of the fertilizer nutritional components can be effectively ensured when the obtained high-purity valine solution is mixed with other nutrients.

The invention provides a nicotinamide nucleotide transhydrogenase mutant and application thereof, valine at the 169th site of the nicotinamide nucleotide transhydrogenase mutant is designed to be mutated into isoleucine, the isoleucine is used for constructing a lysine production strain, and the new strain does not contain plasmids, does not have growth defects, does not need induction, and has the advantages of good genetic stability, high fermentation yield and the like. The lysine can be efficiently and stably produced from the beginning by taking glucose as a substrate.