137 results about "Lactic dehydrogenase" patented technology

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

The invention discloses a biomarker for nephrotic syndrome, an analysis method and a kit, which can be effectively used for diagnosis of nephrotic syndrome and have high sensitivity and accurate and reliable results. The biomarker for nephrotic syndrome comprises the mRNA, the protein and the enzymatic activity level of the following substances: lactate dehydrogenase B.

The invention relates to the field of bioengineering, in particular to an enzyme composition, a product and application of the enzyme composition in preparation of Ectoine. The invention provides an enzyme composition. The enzyme composition comprises a mutant of 2-hydroxy-4-aminobutyric acid oxidase, a mutant of keto transaminase, a mutant of hydroperoxide hydrolase, a mutant of Ectoine synthetase, a mutant of pyruvic acid-CoA oxidase and lactobacillus helveticus lactic dehydrogenase. According to the method disclosed by the invention, a plurality of mutant enzymes are utilized for combined transformation for the first time, and cheap 2-hydroxy-4-aminobutyric acid is taken as a starting raw material to quickly and efficiently produce Ectoine; the enzyme method has the characteristics of easiness in control, short conversion time, few generated impurities and the like, so that the method has unique advantages in the aspects of low-cost and large-scale mass production of Ectoin.

The invention discloses an extraction method of safflower leaf exosome-like nano-vesicles and application of the safflower leaf exosome-like nano-vesicles in preparation of drugs for preventing and treating adriamycin-induced cardiotoxicity, fresh safflower leaves are taken and cleaned, a PBS solution is added for crushing and filtering, filtrate is collected and continuously centrifuged, supernate is taken and subjected to ultracentrifugation, precipitates are collected after centrifugation, and the safflower leaf exosome-like nano-vesicles are obtained; and filtering and sterilizing by using a filter membrane to obtain the safflower leaf exosome-like nano-vesicles. The carthamus tinctorius leaf exosome-like nano-vesicles can significantly improve the heart function of doxorubicin-induced cardiotoxic mice; myocardial injury induced by doxorubicin can be repaired, and myocardial fibrosis induced by doxorubicin can be inhibited; the content of a myocardial injury marker lactic dehydrogenase in body serum can be reduced, a new treatment strategy is provided for preventing and treating adriamycin-induced cardiotoxic diseases, and the application prospect is good.

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

The invention discloses combined probiotics for improving sarcopenia as well as a preparation method and application of the combined probiotics, and belongs to the field of probiotics. The invention relates to a combined probiotic for improving sarcopenia. The combined probiotic comprises a lactobacillus reuteri body, a lactobacillus johnsonii body, a lactobacillus fermentum body and a bifidobacterium adolescentis body. The combined probiotics disclosed by the invention can be used for remarkably improving the overall symptoms of sarcopenia model mice, including inhibiting weight loss, constipation symptoms and colonic mucosa destruction, prolonging load swimming time, improving muscle endurance, improving skeletal muscle atrophy, improving the expression of I-type slow muscle fiber protein MyHC I and promoting slow muscle fiber repair, and has the effects of preventing and treating sarcopenia. The invention discloses a probiotic intervention method for treating sarcopenia, which comprises the following steps of: preparing probiotics for treating sarcopenia, reducing the content of inflammatory cytokines in muscular tissues, increasing the content of hepatic glycogen, improving systematic metabolism of mice with sarcopenia and damaged serum markers, including lactic acid, lactic dehydrogenase, creatine kinase, creatinine, alanine transaminase ALT and aspartate transaminase AST, providing a new scheme for probiotic intervention for sarcopenia, and being used for preparing related functional products or intervention means.

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

The invention discloses a construction method of an escherichia coli mutant for producing succinic acid by fermentation of a synthetic medium. The method comprises the following steps: firstly, knocking out a lactic dehydrogenase gene ldhA, a pyruvate formate lyase gene pflB, a ptsG gene responsible for encoding a phosphotransferase system EIIBC protein, an ethanol dehydrogenase gene adhE, an acetokinase-phosphate transacetylase gene ackA-pta, and a ptsG gene responsible for encoding a phosphotransferase system EIIBC protein in escherichia coli; a phosphoenolpyruvate carboxykinase gene pck from bacillus subtilis is integrated at an SS9 safety site of a strain to obtain escherichia coli ESC6 with high succinic acid yield; and mutating one or more loci in one or more genes of a glucose-transcriptional inhibition factor gene mlc, a nitrate response regulatory factor gene narL and a cyclic adenylate receptor protein gene crp to obtain the escherichia coli mutant capable of producing succinic acid by fermentation of a synthetic culture medium, wherein the one or more loci in one or more genes of the glucose-transcriptional inhibition factor gene mlc, the nitrate response regulatory factor gene narL and the cyclic adenylate receptor protein gene crp are mutated. The strain can be fermented in a synthetic medium to produce succinic acid, so that the fermentation cost is greatly reduced, and the strain has a very wide application prospect.

The invention discloses application of lycium barbarum polysaccharide in preparation of a medicine for inhibiting methylamphetamine-induced nerve injury, and relates to the technical field of biological medicines. It is found and proved that lycium barbarum polysaccharide can inhibit methylamphetamine-induced nerve injury, and the effect is remarkable. From the aspect of cell survival, the survival rate of the microglial cells pretreated by the lycium barbarum polysaccharide after METH stimulation is obviously improved. In the molecular mechanism, the lycium barbarum polysaccharide can effectively lower the protein expression level of the METH-induced pyroptosis marker, the content of inflammatory factors IL-1beta and IL-18 can be reduced, and the release of lactic dehydrogenase is reduced. The result shows that the lycium barbarum polysaccharide can alleviate inflammatory response by inhibiting NLRP3 / ASC pathway mediated microglial cell pyroptosis, thereby inhibiting METH-induced nerve injury. The invention provides a new direction for developing METH neurotoxicity intervention medicines.

The invention relates to the field of biological catalysis, and discloses a method and a device for generating ursodesoxycholic acid through continuous flow catalysis of chenodeoxycholic acid. Comprising the following steps: (1) in the presence of first immobilized cells, carrying out a first catalytic reaction on a reaction system containing chenodeoxycholic acid to obtain a first product, the first immobilized cells expressing 7 alpha-hydroxysteroid dehydrogenase and lactic dehydrogenase; the concentration of the chenodeoxycholic acid in the reaction system is 40 to 70 mM; (2) adjusting the pH value of the first product to 8-9, and then in the presence of a second immobilized cell, carrying out a second catalytic reaction on the first product after the pH value is adjusted to obtain ursodesoxycholic acid, and the second immobilized cell expresses 7 beta-hydroxysteroid dehydrogenase and glucose dehydrogenase. According to the method, the stable activity of a catalytic system is kept, efficient conversion of high-concentration CDCA is achieved, meanwhile, precipitation of 7-KLCA is thoroughly avoided, and the synthesis efficiency, the product purity and the process continuity of UDCA are remarkably improved.

The invention discloses a lactic dehydrogenase LdLDH mutant and application thereof, a wild type LdLDH enzyme derived from Lactobacillus delbrueckii subsp. Bulgaricus is taken as a research object, the amino acid sequence of the wild type LdLDH enzyme is designed and modified to obtain a mutant protein, the mutant protein is named as LdLDH-M, the amino acid sequence of the mutant protein is shown as SEQ ID NO.2, the Tm value of the LdLDH-M is 77.1 DEG C, the Tm value of the LdLDH-M is 77.1 DEG C, and the Tm value of the LdLDH-M is 77.1 DEG C; compared with the wild type LdLDH enzyme, the Tm value of the LdLDH enzyme is increased by 27.4 DEG C, and the enzyme activity of the LdLDH enzyme is increased by 1.4 times. Therefore, compared with the wild type LdLDH enzyme, the LdLDH-M has remarkably improved thermal stability and enzymatic activity, and is more beneficial to widening the application range of the LdLDH-M in the fields of high-temperature biological research, industrial biological catalysis and the like.

The invention relates to application of an asparagine endopeptidase inhibitor in preparation of a medicine for improving insulin resistance. According to the application, starting from inhibiting the aging driving factor AEP, the AEP inhibitor is tried to be applied to the research of insulin resistance for the first time, and the AEP inhibitor is found to be capable of remarkably improving glucose tolerance and insulin sensitivity. Therefore, the invention provides the application of the asparagine endopeptidase inhibitor in preparation of the medicine for improving insulin resistance. Experiments prove that the AEP inhibitor not only can significantly enhance insulin sensitivity of old mice and improve glucose tolerance, but also can reduce serum low-density lipoprotein cholesterol and lactic dehydrogenase levels, shows multiple improvement effects on glucose metabolism and lipid metabolism, and also can be used for preparing the AEP inhibitor. After long-term administration, obvious toxic and side effects are not found in pathological examinations of blood routine examination, urine routine examination, heart, liver, spleen, lung, kidney and other important organs, so that the traditional Chinese medicine composition is proved to have good safety and is suitable for long-term intervention of chronic diseases.

The invention discloses a recombinant bacterium for synthesizing phenyllactic acid as well as a construction method and application thereof, and relates to the technical field of microorganisms. The recombinant strain expresses lactic dehydrogenase, and overexpresses YjbB, MdtF, LapA and / or OrtT. According to the invention, a strain for producing the phenyllactic acid is modified by replacing promoters of yjbB, mdtF, lapA and / or ortT genes with strong promoters and the like, so that the strain overexpresses YjbB, MdtF, LapA and / or OrtT, and the yield of the phenyllactic acid can be obviously improved.

The invention discloses a recombinant bacterium for producing L-lactic acid through co-utilization of glucose and xylose as well as a construction method and application of the recombinant bacterium. The invention relates to the technical field of biology, in particular to recombinant bacteria for producing L-lactic acid through co-utilization of glucose and xylose as well as a construction method and application. Methylglyoxal synthase, and / or pyruvate formate lyase, and / or fumarate reductase and / or L-lactic dehydrogenase in receptor Escherichia coli Rec1.0 are modified to obtain recombinant Escherichia coli, the recombinant Escherichia coli is fermented for 24 h, L-lactic acid is the only metabolite, and the yield reaches 2458 g / L; the consumption rate of xylose is 0.76 g / g DCW / h, the consumption rate of glucose is 0.69 g / g DCW / h, and the consumption rate of total sugar reaches 1.45 g / g DCW / h. The recombinant Escherichia coli constructed by the invention can realize efficient utilization of lignocellulose hydrolysate (containing glucose and xylose), and has a wide application prospect.

The invention discloses a traditional Chinese medicine composition for improving memory and concentration and a preparation method thereof, and relates to the technical field of traditional Chinese medicine formulas. The traditional Chinese medicine composition is prepared from the following raw materials in parts by weight: 12-22 parts of fructus alpiniae oxyphyllae, 15-25 parts of radix astragali, 8-16 parts of ginseng, 10-20 parts of walnuts, 10-20 parts of radix puerariae, 6-14 parts of cornel pulp, 8-18 parts of radix rehmanniae, 10-20 parts of Chinese wolfberry fruits, 15-25 parts of spina date seeds, 8-16 parts of polygala tenuifolia, 6-14 parts of rhizoma acori graminei and 4-10 parts of earthworms. According to the traditional Chinese medicine composition for improving memory and concentration and the preparation method of the traditional Chinese medicine composition, polygala ketone contained in polygala tenuifolia can specifically up-regulate hippocampal BDNF expression and doubly repair memory pathway damage caused by alcohol, volatile asarone in acorus gramineus can penetrate a blood brain barrier, and the volatile asarone is compatible with polygala tenuifolia, so that the nerve stimulation threshold value of a single component can be reduced, the intelligence promoting effect can be improved, and the traditional Chinese medicine composition can be used for improving memory and concentration. The earthworm extract can inhibit the activity of lactic dehydrogenase in the brain, and the synergistic effect mechanism of the polygala tenuifolia, the rhizoma acori graminei and the earthworm can also play a role in preventing and treating the Alzheimer's disease.

The invention belongs to the technical field of biological enzymes, and particularly relates to mutant clostridium sporogenes source phenyllactic dehydrogenase, a method for preparing indole-3-lactic acid from the mutant clostridium sporogenes source phenyllactic dehydrogenase and application of the mutant clostridium sporogenes source phenyllactic The mutant type clostridium sporogenes source phenyllactic acid dehydrogenase comprises N53V mutant type clostridium sporogenes source phenyllactic acid dehydrogenase, R154K mutant type clostridium sporogenes source phenyllactic acid dehydrogenase and N53V / R154K mutant type clostridium sporogenes source phenyllactic acid dehydrogenase. The amino acid sequences of the polypeptide are respectively shown as SEQ ID NO: 6, SEQ ID NO: 10 and SEQ ID NO: 12. Constructing a genetically engineered bacterium for expressing the mutant phenyllactic dehydrogenase in escherichia coli; and tryptophan can be efficiently fermented and catalyzed to be converted into indole-3-lactic acid, and the yield of the indole-3-lactic acid generated by fermentation is increased to 1.85 times, so that the mutant has a very good application prospect in the aspect of fermentation preparation of the indole-3-lactic acid.

The present invention discloses a D-lactic acid content determination kit and a determination method, and relates to the technical field of D-lactic acid content determination, the D-lactic acid content determination kit comprises a detection box body, the side of the detection box body is provided with an assembly strip for assembly, and the upper part of the detection box body is provided with a protection cover, a mixing barrel for mixing reagents is arranged on the outermost side of the detection box body on the end side, an auxiliary base is fixedly connected to the interior of the detection box body, a clamping plate is arranged on the upper side of the auxiliary base, and an adjusting mechanism is arranged in the auxiliary base. According to the D-lactic acid content determination kit and the determination method, pyruvic acid is generated from D-lactic acid under the action of D-lactic dehydrogenase, and NAD < + > is reduced to generate NADH; in order to smoothly carry out the reaction, an enzyme is additionally added to further decompose pyruvic acid, NADH is generated and reacts with a specific color developing agent to generate a colored substance with the maximum absorption peak at the position of 450 nm, and the content of D-lactic acid is calculated by detecting the increment of the substance at the position of 450 nm.

The invention relates to the technical field of blood detection, in particular to a formula of an optimized alanine aminotransferase kit, which has the technical scheme that lactic dehydrogenase, NADH (nicotinamide adenine dinucleotide), DCA-Na, glycerol and a Proclin-300 preservative are dissolved in a reagent I Tris buffer solution of the ALT kit; l-alanine, alpha-ketoglutaric acid, glycerol and a Proclin-300 preservative are dissolved in a Tris buffer solution of the reagent II, DCA-Na in the kit is an activator of a pyruvate-lactic dehydrogenase compound and inhibits the kinase activity of pyruvate dehydrogenase, glycerol is an enzyme activity stabilizer, Proclin-300 is a preservative, an instrument is used for detection at the main wavelength of 340 nm and the auxiliary wavelength of 380 nm, and the detection result is accurate. And calculating the ALT activity according to the decreasing rate of NADH (nicotinamide adenine dinucleotide).

The present invention belongs to the field of biotechnology, and particularly relates to a bionic synthesis engineering bacterium of compound Danshen and its application. The engineering bacterium is obtained by introducing cytochrome P450 reductase, tyrosine hydroxylase and D-lactate dehydrogenase of Lactobacillus pentosus on the basis of a Saccharomyces cerevisiae starting bacterium that produces protopanaxadiol, cryptotanshinone diene and borneol. The obtained Saccharomyces cerevisiae genetic engineering bacterium can simultaneously synthesize the active ingredients of compound Danshen preparations, namely protopanaxadiol, cryptotanshinone diene, danshensu and borneol, and has application value.

The invention discloses a preparation method and application of a lactic dehydrogenase mutant with improved thermal stability. The lactic dehydrogenase mutant is obtained by amplifying a mutation primer by taking a plasmid of wild lactic dehydrogenase as a template; the amino acid sequence of the wild type lactic dehydrogenase is as shown in SEQ ID NO. 1; lactic dehydrogenase mutants M53D and S309P with improved thermal stability are obtained, the residual enzyme activity of the S309P mutant is 76% after the S309P mutant is incubated for 1.5 h at 50 DEG C, and only 50% of the activity of wild type enzyme remains under the same treatment condition.

The invention discloses an application of sodium oxamate in preparation of anti-influenza virus products, and provides an application of sodium oxamate as a lactic dehydrogenase A inhibitor in preparation of anti-influenza virus products, the sodium oxamate has broad-spectrum antiviral activity, and can play a unique action mechanism by regulating host cell metabolism (such as protein lactylation). And a new direction is provided for overcoming virus resistance.

The invention discloses a genetically engineered bacterium for synthesizing N-acetyl blue as well as a construction method and application of the genetically engineered bacterium. The genetically engineered bacterium is prepared by knocking out a lactic dehydrogenase gene ldh and inserting a phosphoketolase gene xfpK on a knockout site, knocking out a pyruvate oxidase gene poxB and inserting a phosphate transacetylase gene pta on a knockout site of a microorganism for producing N-acetyl blue, and knocking out an aconitase inhibition factor gene acnR, inserting a glutamate dehydrogenase gene gdhA on a knockout site, knocking out a glutamine synthetase adenylation transferase gene glnE, and inserting an alpha-ketoglutarate dehydrogenase inhibition factor gene odhI on a knockout site to obtain the strain. According to the method, the supply of the precursor acetyl coenzyme A is enhanced by introducing a non-oxidative glycolysis pathway, the pH dynamic regulation system balances the metabolic flux, and the double breakthrough of the yield and the carbon recovery rate of the N-acetyl blue is realized by combining a two-stage fermentation process.

The present application relates to the application of sulfasalazine combined with lactate dehydrogenase inhibitor in preparing the inhibition of TIF1 gamma lactic acid product, belongs to the field of biological medicine technology. The present application finds that sulfasalazine can block the lactic acidification of the 763th and 769th lysine of transcription intermediate factor 1 gamma (TIF1 gamma), and the combination of sulfasalazine and lactate dehydrogenase inhibitor can strengthen the block of the lactic acidification of the 763th and 769th lysine of transcription intermediate factor 1 gamma, improve the expression level of TIF1 gamma, and then improve the treatment effect on TIF1 gamma related cancer.

The invention relates to the technical field of biology, and discloses a genetically engineered bacterium for high yield of 1, 4-butanediol and application of the genetically engineered bacterium. Escherichia coli is used as a chassis bacterium, a gene ldhA for coding lactic dehydrogenase, a gene adhE for coding ethanol dehydrogenase, a gene pflB for coding formate lyase, and a gene gabD and a gene yneI for coding succinate semialdehyde dehydrogenase are knocked out from a chassis bacterium genome, expression of a succinate semialdehyde dehydrogenase gene sucD and a 4-hydroxybutyrate dehydrogenase gene 4hbD is strengthened, a pdhR gene is knocked out, and a recombinant plasmid is obtained. The expression of the gene gltAR164L is enhanced, the gene mdh, the gene arcA, the gene poxB, the gene sdhAB and the gene ptsG are knocked out, and the expression of the glf gene and the ppc gene is enhanced; the method comprises the following steps of: transferring plasmids carrying a gene ald for coding aldehyde dehydrogenase, a gene cat2 for coding acyltransferase and a gene yqhD for coding alcohol dehydrogenase into a chassis bacterium, and carrying out metabolic transformation to obtain a genetically engineered bacterium which carries exogenous plasmids and has the capabilities of high yield and extracellular accumulation of 1, 4-BDO, so that the yield of 1, 4-BDO can be increased to 4.71 g / L.

The invention discloses a lactic dehydrogenase mutant, a biological material, a catalyst and application, and belongs to the field of protein engineering, the lactic dehydrogenase mutant has one or more amino acid residue mutations in the 234th site, the 248th site and the 251st site compared with wild lactic dehydrogenase derived from Petroga mobilis. According to the finally obtained mutant, the regeneration efficiency of the reduced coenzyme NADH is remarkably improved, and the catalytic efficiency of the preferable mutant S234R / G248C / Y251R is 1.64 times that of wild type lactic dehydrogenase; meanwhile, the reaction condition range of lactic dehydrogenase is effectively expanded, and the mutant can efficiently catalyze and synthesize NADH under the conditions that the temperature is 20-40 DEG C and the pH value is 7-11.

The invention discloses a traditional Chinese medicine composition for treating ischemic diseases of lower limbs and also provides a preparation method of the traditional Chinese medicine composition, the synergistic combination effect of the two medicines is exerted, the curative effect of a single medicine is obviously improved, and the anticoagulant effect is far greater than that of the independent administration of caltrop; the sum of the action intensity of two independent administration is achieved, and the in-vitro anticoagulation effect and the effect of improving the ischemic blood flow of the lower limbs can be remarkably improved; blood vessel growth factors are remarkably increased, the activity of creatine kinase and lactic dehydrogenase is reduced, and tissue damage is relieved; glutathione peroxidase is promoted, malondialdehyde and active oxygen are inhibited, and the anti-oxidation effect is achieved; hypoxia and mitochondrial functions can be improved by inhibiting hypoxia-inducible factors (hypoxia-inducible factors)-1 alpha and mitochondrial compounds 3; the anti-inflammatory effect can be achieved by inhibiting CRP, IL-1beta and TNF-alpha; the rat lower limb ischemia can be obviously improved and treated.

The invention discloses recombinant klebsiella pneumoniae with high yield of 3-hydracrylic acid as well as a construction method and application of the recombinant klebsiella pneumoniae, and belongs to the technical field of genetic engineering. The construction method comprises the following steps: by taking klebsiella pneumoniae as an original strain, introducing kgsadh genes for coding alpha-ketoglutarate semialdehyde dehydrogenase, and knocking out 1, 2, 3, 4-tetramethyl-3-oxoglutarate; the method comprises the following steps: constructing recombinant klebsiella pneumoniae for high yield of 3-hydracrylic acid by using one or more of a dhaT gene of 1, 3-propylene glycol dehydrogenase, an ldh gene for coding L-lactic dehydrogenase, an ldhA gene for coding 2-hydracrylic acid dehydrogenase and a yqhD gene for coding alcohol dehydrogenase. Compared with an initial strain and a recombinant strain, the 3-HP of the recombinant strain is remarkably improved, and the yield of the 3-HP is the highest when an organic nitrogen source is determined to be corn steep liquor or the concentration of glycerol is controlled to be 15-25g / L through organic nitrogen source optimization and glycerol concentration control, so that a new strain choice is provided for high yield of the 3-hydracrylic acid.

The invention discloses a method for detecting the concentration of acetic acid in an anaerobic fermentation system by using a bioelectrochemical sensor, acetic acid is detected by using the bioelectrochemical sensor, the bioelectrochemical sensor comprises a screen-printed electrode, and the working surface of the screen-printed electrode is modified with reduced graphene oxide and polymethylene blue. The working surface of the screen printing electrode is connected with acetokinase, pyruvate kinase and lactic dehydrogenase through a cross-linking agent. According to the method, the adopted sensor has better conductivity, higher response speed and higher current intensity, when the sensor is used for detecting the concentration of acetic acid in a fermentation system, the sensor has the advantages of being easy to operate, low in sample consumption, low in price, high in accurate measurement precision, high in detection speed and the like, and rapid detection of the concentration of acetic acid can be achieved; the acetic acid concentration in the anaerobic fermentation process in different periods can be timely and accurately obtained, effective data can be provided for anaerobic fermentation analysis, and the method has important significance for monitoring the process stability of anaerobic fermentation.

The invention discloses a mutated D-lactic dehydrogenase gene related to gout, a kit and application of the mutated D-lactic dehydrogenase gene. A coding region (CDS) of the mutated D-lactic dehydrogenase gene contains c.1327Cgt; t, and c.1058Cgt; the D-lactic dehydrogenase gene is a mutation site A, and the Genbank login number of the D-lactic dehydrogenase gene before mutation is NM194436.3. According to the invention, high-throughput sequencing of all exon regions is carried out on a young gout patient of Chinese Han nationality and parents thereof by adopting a whole exon group sequencing technology, and biological information analysis is combined to find that c.1327Cgt simultaneously exists on an LDHD gene (reference sequence gene NM194436.3) of the gout patient; t (p.His443Tyr) and c.1058Cgt are selected from the group consisting of Cgt and Cgt; a (p.Ala353Glu) autosome recessive genetic mode mutation is carried out. The mutation is associated with causing an increase in D-lactic acid in serum and urine of a patient and with gout. According to the invention, the understanding of LDHD-related mutation genetic modes is expanded, the research direction of gout pathogenesis is expanded, and a technical means is provided for developing effective early pathogenic gene screening.