125 results about "Dehydratase" patented technology

The invention provides a genetically engineered bacterium for synthesizing fucosyllactose as well as a preparation method and application of the genetically engineered bacterium. The genetically engineered bacterium is prepared by knocking out a glucose-1-phosphate undecanoate transferase gene wcaJ and a beta-galactosidase gene lacZ on the basis of an original strain, the invention relates to an overexpression gene of a phosphomannose gene manB, a phosphoguanine transferase gene manC, a GDP-mannose-4, 6-dehydratase gene gmd, a GDP-fucose synthetase gene WcaG and a beta-galactoside permease gene lacY, and further, the overexpression gene of an alpha-1, 2-fucosyltransferase or an alpha-1, 3-fucosyltransferase is also used for the overexpression of a phosphomannose gene manB, a phosphoguanine transferase gene manC, a GDP-mannose-4, 6-dehydratase gene gmd, a GDP-fucosyltransferase gene. According to the invention, the modified Escherichia coli probiotic Nissle1917 is preferably used as a host for biosynthesis of fucosyllactose, no endotoxin hidden danger exists, and a foundation is laid for industrial production of fucosyllactose.

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 application of threonine dehydratase in regulation and control of growth of Didymeria segeticola and application of threonine dehydratase serving as a bactericide target in regulation and control of growth of Didymeria segeticola. The threonine dehydratase gene Td disclosed by the invention is derived from Didymeria segeticola, and a knockout mutant is obtained by constructing a knockout gene segment of the Td gene and introducing the knockout gene segment into a D.segeticola protoplast. Experiments find that the Td gene plays a role in growth of D.segeticola, in-vivo pyruvic acid content, in-vivo ATP (adenosine triphosphate) content and sensitivity to wuyiencin. Molecular docking analysis, molecular dynamics simulation and trace thermophoresis experiments prove that the threonine dehydratase can be used as a bactericide target, and the bactericide wuyiencin is obtained through screening. The threonine dehydratase disclosed by the invention can be used as a bactericide target and a key protein of a disease pathogenic mechanism, and has a wide application prospect in prevention and treatment of plant pathogenic fungal diseases.

The invention belongs to the field of biology, and particularly relates to a fusion protein for promoting synthesis of 1, 3-propylene glycol and application of the fusion protein. The fusion protein NADPH (Nicotinamide Adenine Dinucleotide Phosphate) dependent alcohol dehydrogenase fusion protein or NADH (Nicotinamide Adenine Dinucleotide Hormone) dependent alcohol dehydrogenase fusion protein disclosed by the invention can be packaged into diol dehydratase and can promote the synthesis of 1, 3-propylene glycol. Experiments prove that the bacillus subtilis has an effect of improving the fermentation performance of the strain.

The invention relates to the field of biological engineering and technology, in particular to an enzyme for synthesizing glabridin, a biological synthesis method of glabridin and a bacterial strain. The invention discloses a series of glabridin synthesizing enzymes (phenylalanine ammonialyase, cinnamic acid-4-hydrogenase, tyrosine ammonialyase, p-coumaric acid coenzyme A ligase, chalcone synthase, chalcone reductase, chalcone isomerase, isoflavone synthase, 2-hydroxyisoflavone dehydratase, 4 '-oxymethyltransferase, 4'-hydroxymethyltransferase and 4 '-hydroxymethyltransferase) derived from glycyrrhiza glabra for the first time. ) can be used in the preparation of a compound (e.g., isoflavone 2 '-hydrogenase, isoflavone reductase, Vissisoketoreductase, isoprenyltransferase, pterocarpin reductase, oxidative cyclase, demethylase, cytochrome P450 reductase, and the like). The de novo synthesis of the glabridin in a microbial cell factory is realized for the first time, and the application prospect of the glabridin biological manufacturing industry is greatly promoted.

The invention relates to a Kluyveromyces cerevisiae gene modified cell containing GDP-mannose dehydratase polypeptide, which can be applied to synthesis of human milk oligosaccharide, and belongs to the field of synthetic biology. According to the technical scheme, the gene modified cell comprises a recombinant nucleic acid sequence for coding a polypeptide with GDP-mannose dehydratase polypeptide (GDP-mannose dehydratase polypeptide) activity. The polypeptide capable of catalyzing the conversion of GDP-mannose into GDP-4-keto-6-deoxymannose comprises a polypeptide of which the amino acid sequence is at least 70%, 75%, 80%, 85%, 90%, 95%, 99% and 100% identical to the amino acid sequence of SEQ ID NO: 1, SEQ ID NO: 2 and / or the amino acid sequence of polypeptides M1-M13, wherein the amino acid sequence of the polypeptide is at least 70%, 75%, 80%, 85%, 90%, 95%, 99% and 100% identical to the amino acid sequence of the polypeptides M1-M13. The invention provides a kluyveromyces kluyveromyces genetically modified cell with fucosyllactose synthesis activity.

The disclosure relates to the field of specialty chemicals and methods for their synthesis. In embodiments, the disclosure provides viable bacterial cells which comprise heterologous dual 3-hydroxy-acyl-ACP dehydratase / isomerases, etc. The disclosure further provides monounsaturated fatty acid derivative molecules produced by the viable bacterial cells which are non-native to the bacterial cells. The disclosure further provides methods for the preparation and production of non-native monounsaturated fatty acid derivative molecules such as e.g., an ω3-monounsaturated fatty acid derivative, an ω5-monounsaturated fatty acid derivative, an ω9-monounsaturated fatty acid derivative, an ω11-monounsaturated fatty acid fatty acid derivative, etc.

The invention relates to the technical field of microbial metabolism engineering, in particular to a corynebacterium glutamicum producing strain for efficiently producing D-pantothenic acid as well as a construction method and application of the corynebacterium glutamicum producing strain. The construction method specifically comprises the following steps: (1) by taking wild corynebacterium glutamicum ATCC 13032 as a chassis, weakening ilvA, and constructing DPA1 through mutation expression; (2) knocking out the quinone pyruvate oxidoreductase and inserting a panBCE gene expression cassette into the quinone pyruvate oxidoreductase to construct DPA2; (3) introducing and using a pEC-xk99E overexpression plasmid to screen and express Escherichia coli W3110, Bacillus subtilis 168, and endogenous acetohydroxy acid synthase, acetolactate isomerized reductoisomerase and 2-hydroxy acid dehydratase, and carrying out a step (2) of carrying out a step (3) of screening and expressing the Escherichia coli W3110, Bacillus subtilis 168, and endogenous acetohydroxy acid synthase, acetolactate isomerized reductoisomerase and 2-hydroxy acid dehydratase in the DPA2; and (4) under the control of a strong promoter, carrying out tandem overexpression on the screened ilvBNCD gene by using pEC-xk99E, constructing DPA3, and enhancing a pantothenic acid main synthesis pathway and an upstream pathway pulling force, thereby obtaining the corynebacterium glutamicum for efficiently producing D-pantothenic acid. The strain provided by the invention can produce D-pantothenic acid with high yield and high conversion rate by utilizing a carbon source, and has important industrial application value.

The invention discloses a production method of fucosylated oligosaccharide. The core of the method is as follows: the GDP-D-rhamnose is converted into the GDP-L-fucose by using the GDP-D-rhamnose-3, 5-epimerase; the GDP-D-rhamnose is obtained by converting the GDP-D-mannose-4, 6-dehydratase and the GDP-4-keto-6-deoxy D-mannose reductase by taking the GDP-D-mannose as a substrate, and the GDP-D-rhamnose is obtained by taking the GDP-D-mannose as a substrate. The invention relates to a method for producing a fucosylated oligosaccharide, which is characterized in that a GDP-D-mannose-4, 6-dehydratase, a GDP-4-keto-6-deoxyD-mannose reductase, a GDP-D-rhamnose-3, 5-epimerase and a fucosyltransferase are expressed in a genetically modified host cell, and the fucosylated oligosaccharide can be produced by the way mentioned above.

The invention belongs to the technical field of genetic engineering, and relates to application of dihydroxy acid dehydratase AcDHAD in improvement of disease resistance of kiwi fruits. The invention discloses a dihydroxy acid dehydratase AcDHAD gene and a dihydroxy acid dehydratase AcDHAD protein coded by the dihydroxy acid dehydratase AcDHAD gene through excavation and functional verification, and confirms the broad-spectrum disease-resistant potential of the dihydroxy acid dehydratase AcDHAD in disease-resistant breeding of kiwi fruits. According to the invention, more gene resources are provided for molecular breeding of disease-resistant varieties of kiwi fruits, so that more opinions and ideas are provided for disease-resistant breeding of kiwi fruits and development of molecular markers.

The invention discloses recombinant yarrowia lipolytica with high yield of 3-fucosyllactose as well as a construction method and application of the recombinant yarrowia lipolytica. According to the invention, a reinforced lactose transporter lac12 gene, a reinforced GDP-mannose-4, 6-dehydratase gmd gene, a reinforced GDP-L-fucose synthase gmer gene and a 3-fucosyltransferase SUMO-fut3Bc gene with a reinforced SUMO tag are subjected to integrated expression on a recombinant yarrowia lipolytica chromosome, and a 6-phosphogluconolactonase pgl gene is subjected to overexpression, so that a recombinant yarrowia lipolytica strain is obtained. The constructed recombinant yarrowia lipolytica can maintain the genetic stability of a target gene, the yield and production efficiency of 3-fucosyllactose are remarkably improved, and the requirements of industrial production can be met.

The invention discloses a Zymomonas mobilis recombinant strain for producing D-pantothenic acid as well as a preparation method and application of the Zymomonas mobilis recombinant strain. A hydroxymethyl transferase gene panB, a ketopantoic acid reductase gene panE and a pantothenic acid synthase gene panC are integrated in a genome of the recombinant strain; an expression plasmid containing an acetolactate synthase gene Bsals, a keto acid reductoisomerase gene ilvC and a dihydroxy acid dehydratase gene ilvD is also transferred into the recombinant strain; wherein the nucleotide sequences of the gene Bsals, the gene ilvC, the gene ilvD, the gene panB, the gene panE and the gene panC are shown as SEQ ID NO. 1 to SEQ ID NO. 6 in sequence. The zymomonas mobilis ZM4 is systematically modified through a genetic engineering means, and an optimal enzyme combination adaptive to the zymomonas mobilis is defined by screening hydroxymethyltransferase, pantothenic acid synthase and ketopantoic acid reductase from different sources, so that a core foundation is laid for efficient operation of a D-pantothenic acid synthesis route, and the method has a wide application prospect. The technical bottlenecks of single metabolic pathway and low synthesis efficiency of the traditional strain are broken through.

Provided herein are host cells capable of producing a human milk oligosaccharide (HMO), such as yeast cells that include one or more heterologous nucleic acids encoding one or more enzymes of the HMO biosynthetic pathway, such as a fucosyltransferase, GDP-mannose dehydratase, lactose permease, and / or fucose synthase. Also provided are fermentation compositions including the disclosed host cells, as well as related methods of producing and recovering HMOs generated by the host cells.

The invention provides a series of GDP-mannose dehydratase polypeptides which can be applied to synthesis of GDP-fucose, and belongs to the technical field of enzyme engineering. The GDP-mannose dehydratase polypeptide comprises a polypeptide of which the amino acid sequence is at least 70%, 75%, 80%, 85%, 90%, 95%, 99% and 100% identical to that of a polypeptide shown in SEQ ID NO: 1, or a polypeptide of which the amino acid sequence is at least 70%, 75%, 80%, 85%, 90%, 95%, 99% and 100% identical to that of a polypeptide M1-13. The GDP-mannose dehydratase polypeptide disclosed by the invention has relatively high catalytic activity.

The invention discloses a recombinant bacterium capable of increasing the yield of alpha-bisabolol as well as a preparation method and application of the recombinant bacterium, and belongs to the technical field of microorganisms. The invention aims to improve the yield of alpha-bisabolol and enhance the tolerance of a host to an organic solvent. The invention provides a recombinant bacterium for improving the yield of alpha-bisabolol. Escherichia coli is used as a starting strain; the method comprises the following steps of: overexpressing an acetyl CoA acyltransferase / HMG-CoA reductase mvaE gene, an HMG-CoA synthetase mvaS gene, a 2-methyl citrate dehydratase prpD gene, a mevalonate kinase ERG12 gene, a mevalonate 5-phosphate kinase ERG8 gene, a mevalonate 5-diphosphate decarboxylase ERG19 gene and an isopentenyl diphosphate isomerase idi gene, so as to obtain a recombinant vector; the gene is obtained from an alpha-bisabolol synthase gene of artichoke, a farnesyl diphosphate synthase ispA gene and an alpha-bisabolol synthase CcBOS gene of artichoke. The industrial process of synthesizing alpha-bisabolol by a biological method is promoted.

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

The present invention discloses a method for synthesizing hydroxytyrosol by multi-enzyme cascade, comprising: 1) preparing a hydroxytyrosol product by using 3,4-dihydroxybenzaldehyde, L-threonine, sodium formate, NAD + As raw material, L-threonine transaldolase, alcohol dehydrogenase, and formate dehydrogenase are used to catalyze the synthesis of L-threo-3-(3,4-dihydroxyphenyl)serine; 2) L-threo-3-(3,4-dihydroxyphenyl)serine is used as substrate, glucose, NAD + Hydroxytyrosol is synthesized through a cascade catalysis of phenylserine dehydratase, α-ketoacid decarboxylase, aldehyde reductase, and glucose dehydrogenase. The synthesis method provided by the present invention achieves a hydroxytyrosol yield of >99% and a space-time yield of 0.88 g / L / h, currently the highest, showing great potential for industrial application and suitable for further promotion and application.

The present invention relates to a novel 2-methylcitrate dehydratase variant and a method for producing L-glutamic acid using same. The 2-methylcitrate dehydratase variant has changed protein activity due to the substitution of at least one amino acid in an amino acid sequence constituting a 2-methylcitrate dehydratase, and thus, L-glutamic acid can be efficiently produced from a recombinant microorganism expressing the variant.

The invention discloses construction and application of genetically engineered bacteria for high-yield rose honey sweet essence. The genetically engineered bacterium is obtained by overexpressing tobacco pre-benzoic acid dehydratase NtPHA2 and an ARO80 mutant ARO80S706T / L877Q / E910D by virtue of saccharomyces cerevisiae. According to the invention, NtPHA2 and an ARO80 mutant ARO80S706T / L877Q / E910D are over-expressed in the saccharomyces cerevisiae, so that the biosynthesis yield of rose honey sweet aroma substances such as 2-phenethyl alcohol and the like is increased, and the rose honey sweet essence can be produced in batches by utilizing the engineering strain.

The invention discloses a preparation method and application of fucose and an intermediate thereof. The method for synthesizing the GDP-fucose comprises the following steps: taking guanosine diphosphate and cane sugar as substrates, and carrying out catalytic reaction on cane sugar synthase, CDP-tetrose 2-epimerase, GDP-mannose dehydratase and isoreductase to generate the GDP-fucose. The method for synthesizing the fucosyllactose comprises the following steps: taking GDP-fucose and pNP-lactose as initial substrates, and obtaining the fucosyllactose under the catalytic action of Hp13FucT2 enzyme. According to the method for preparing the L-fucose through the enzyme method, fucosyllactose is used as a substrate, and the L-fucose is generated through a fucosidase catalytic reaction. The adopted large intestine expression system has the characteristics of high expression efficiency, large expression quantity, low cost, easiness in operation and the like, and the expressed fucosidase has the advantages of high purity, high yield and the like.

The invention discloses an application of a soybean 2-hydroxyisoflavanone dehydratase gene in improving the growth of intercropping corn. The gene HID1 can promote soybean to synthesize isoflavone, recruit bacillus and promote mycorrhizal fungi infection, so that the growth of intercropped corn is promoted, and the gene HID1 has important significance in illuminating the biological function of the GmHID1 gene in leguminous crop intercropping and regulating and controlling the synergistic growth promotion of plants, mycorrhizal fungi and bacillus in intercropping.

The application belongs to the technical field of genetic engineering, and particularly relates to a genetically engineered bacterium for producing L-valine and a construction method and application thereof. The genetically engineered bacterium takes Escherichia coli as a host, heterologously overexpresses alss genes of Bacillus subtilis for coding acetyl-lactate synthetase and bcd genes for coding leucine dehydrogenase, brnFE genes of Corynebacterium glutamicum for coding branched-chain amino acid membrane transport proteins, and overexpresses ilvC genes of Escherichia coli for coding ketol-acid reductoisomerase mutants L67E / R68F / K75E, ilvD genes for coding dihydroxy-acid dehydratase, gapA genes for coding 3-phosphoglyceraldehyde dehydrogenase and pncB genes for coding nicotinate phosphoribosyltransferase; and does not express mdh genes for coding malate dehydrogenase; and replaces thioctamide dehydrogenase with a mutant A321T. A genetically engineered bacterium for stably and efficiently producing L-valine is obtained.

The invention relates to a recombinant halomonas, which comprises an ilvC (acetohydroxy acid isoreductase, AHAIR) gene, an ilvD (dihydroxy acid dehydratase, DHAD) gene and an optional ilvE (transaminase, TA) gene, wherein the ilvC (acetohydroxy acid isoreductase, AHAIR) gene and the ilvD (dihydroxy acid dehydratase, DHAD) gene are externally introduced. According to the recombinant halomonas disclosed by the invention, the L-leucine and / or the L-isoleucine can be efficiently produced without sterilization, in an energy-saving and water-saving manner through open type fermentation, and the industrial production of the recombinant halomonas is facilitated.

This invention belongs to the fields of fermentation and genetic engineering technology, and provides a high-yield hexanoic acid-producing engineered *Escherichia coli* strain, its construction method, and its applications. This engineered strain is *Escherichia coli*... E. coli w3110 was the starting strain, overexpressing the acetyl-CoA transferase gene. act and β-ketothiolase gene bktB Overexpression of trans-enoyl-CoA reductase gene ter 3-Hydroxybutyryl-CoA dehydrogenase gene hbd, and 3-hydroxybutyryl coenzyme A dehydratase gene crt Or, simultaneously not expressing the pyruvate formate lyase gene. pflB or lactate dehydrogenase gene ldhA This engineered bacteria can convert glucose into hexanoic acid, a high-value product, with a yield of 4.968 g / L after 18 hours of fermentation. It adopts aerobic fermentation, resulting in rapid cell growth, a short fermentation cycle, and a high acid production rate. The fermentation process is simple, easy to control, and has low production costs, which is conducive to its promotion and application in industrial production.

The invention provides genetically engineered saccharomycetes capable of simultaneously producing baicalein and baicalin as well as a construction method and application of the genetically engineered saccharomycetes. According to the invention, by weakening or deleting a glucose 5-phosphate dehydrogenase gene (ZWF1) and phenylpyruvate decarboxylase genes ARO10 and PDC5 in a saccharomyces cerevisiae genome and enhancing the expression of a pre-benzoic acid dehydratase gene Pha2, the metabolic flow of a shikimic acid pathway is increased, the aldrin pathway is blocked, and the yield of the shikimic acid pathway is increased. Therefore, the yield of L-phenylalanine serving as a starting material for synthesizing baicalein and baicalin is increased; meanwhile, exogenous genes PAL, 4CL, CHS, CHI, FNSII, F6H, CPR and F7GAT are integrated onto the genome by virtue of a gene recombination technology, so that baicalein and baicalin are produced from the beginning by taking glucose and glycerol as a mixed carbon source without adding precursor substances such as exogenous L-phenylalanine or malonyl CoA and the like.

A method of synthesizing(S)-3-hydroxy-γ-butyrolactone (HBL), the method including producing a trione using an enzymatic conversion of glucosone. The enzymatic conversion may include: mutating a domain of Aldos-2-ulose dehydratase (AUDH) to obtain a mutant AUDH; dehydrating glucosone using the mutant AUDH to obtain an intermediate, basidiopyrone P (BPP) (4,5-dihydroxy-2-(hydroxymethyl)-2H-pyran-5-one); and forming the trione from the BPP. The method may further include catalyzing the trione using a base to form an ester of 3,4-dihydroxybutyrate; and converting the ester of 3,4-dihydroxybutyrate into the HBL by adding an acid to the ester of 3,4-dihydroxybutyrate.

The disclosure relates to the field of specialty chemicals and methods for their synthesis. In embodiments, the disclosure provides viable bacterial cells which comprise heterologous dual 3-hydroxy-acyl-ACP dehydratase / isomerases, etc. The disclosure further provides monounsaturated fatty acid derivative molecules produced by the viable bacterial cells which are non-native to the bacterial cells. The disclosure further provides methods for the preparation and production of non-native monounsaturated fatty acid derivative molecules such as e.g., an ω3-monounsaturated fatty acid derivative, an ω5-monounsaturated fatty acid derivative, an ω9-monounsaturated fatty acid derivative, an ω11-monounsaturated fatty acid fatty acid derivative, etc.

The present invention relates to a composition for preventing or treating metabolic diseases by using a strain, that expressing tartaric acid dehydratase, or combination therapy comprising same. If a Limosilactobacillus fermentum strain expressing tartaric acid dehydratase is co-administered with tartaric acid, citric acid, or materials containing each of tartaric acid and citric acid, according to one aspect, the present invention is very effective in preventing or treating metabolic diseases through a synergistic effect of anti-obesity activity.

Disclosed in the present invention is the use of a threonine dehydratase in the regulation of the growth of Didymella segeticola and as a bactericide target. The threonine dehydratase gene Td of the present invention is derived from Didymella segeticola, and a knockout mutant is obtained by means of constructing a knockout gene fragment targeting the Td gene and then introducing same into a D. segeticola protoplast. Experiments find that the Td gene plays a role in the growth, the in-vivo pyruvic acid content and the in-vivo ATP content of D. segeticola, and the sensitivity thereof to wuyiencin. By means of molecular docking analysis, molecular dynamics simulation and microscale thermophoresis experiments, it is verified that threonine dehydratase can be used as a bactericide target, and the bactericide wuyiencin is obtained by means of screening. The threonine dehydratase of the present invention can be used as a bactericide target and a key protein in the pathogenic mechanism of a disease, and has broad application prospects in the control of plant pathogenic fungal diseases.

The invention discloses a recombinant microorganism for producing alpha-ketoisovaleric acid as well as a preparation method and application of the recombinant microorganism. The recombinant microorganism for producing alpha-ketoisovaleric acid, disclosed by the invention, has the following characteristics: the recombinant microorganism contains a substance capable of expressing an acetolactate synthase gene and / or a substance capable of promoting the expression of the acetolactate synthase gene and / or a substance capable of improving the activity or content of acetolactate synthase; the composition contains a substance capable of expressing an acetohydroxy acid reductoisomerase gene and / or a substance capable of promoting the expression of the acetohydroxy acid reductoisomerase gene and / or a substance capable of improving the activity or content of acetohydroxy acid reductoisomerase; the composition contains a substance capable of expressing a dihydroxy acid dehydratase gene and / or a substance capable of promoting the expression of the dihydroxy acid dehydratase gene and / or a substance capable of improving the activity or content of the dihydroxy acid dehydratase. Experiments prove that the recombinant microorganism disclosed by the invention can be used for producing alpha-ketoisovaleric acid by utilizing glucose and has a very good application prospect.