32 results about "Butanediol dehydrogenase" patented technology

A high flux of metabolites from pyruvate to 2,3-butanediol in Lactobacillus plantarum was achieved through genetic engineering. Substantial elimination of lactate dehydrogenase activity in the presence of heterologously expressed butanediol dehydrogenase activity led to 2,3 butanediol production that was at least 49% of the total of major pyruvate-derived products.

The invention discloses an E. coli BL21(pETDuet-ydjLnox) containing a 2R,3R-butanediol dehydrogenase gene ydjL and an NADH oxidase gene nox, wherein the strain is preserved in the 'China Center for Type Culture Collection' on December 23 in 2008, and the preservation number is CCTCC NO: M 208259. The invention also discloses application of a gene recombination bacterium in producing chiral S-AC by catalyzing meso-BD, producing chiral R-AC by catalyzing 2R,3R-BD and producing chiral pure 2S,3S-BD by splitting a 2,3-BD mixture. The concentration of a chiral AC prepared from the recombinant E. coli can reach over 6 grams per liter (the ee value is more than or equal to 96 percent); and the ee value of the chiral pure 2S,3S-BD is more than or equal to 98 percent, and the regeneration of a cofactor is achieved, thus the gene recombination bacterium has great industrial application prospect.

The invention discloses (2R, 3R)-2,3-butanediol dehydrogenase from paenibacillus polymyxa ATCC12321 and a coding gene and application thereof. Zymology verifies that the dehydrogenase has new characteristics: (2R, 3R)-2,3-butanediol is catalyzed to generate (R)-acetoin and meso-2,3-butanediol is catalyzed to generate (S)-acetoin by taking NAD+ as coenzyme, and the (R)-acetoin is catalyzed to generate (2R, 3R)-2,3-butanediol, the (S)-acetoin is catalyzed to generate meso-2,3-butanediol, and butanedione is catalyzed to generate (R)-acetoin by taking NADH as coenzyme. Moreover, the dehydrogenasesubstrate has high specificity and wide industrial application prospect.

The invention discloses a lactose induction type expression vector, which can utilize cheap lactose to replace expensive isopropyl thioamide-beta-D- galactoside (IPTG) to be exutory. The lactose induction type expression vector can be widely used on the expression of exogenous gene and the reconstruction of serratia marcescens metabolic pathway, for example, the lactose induction type expression vector is used to lead meso-2,3-butanediol dehydrogenase (meso-2,3-BDH) in serratia marcescens. The invention also discloses a serratia marcescens which utilizes gene recombination technique to reconstruct, which changes the metabolic pathway of natural meso-2,3-butanediol in bacteria through leading in exogenesis meso-2,3-butanediol dehydrogenase (meso-2,3-BDH) gene. The serratia marcescens which is reconstructed by gene recombination technique which is provided by the invention expresses meso-2,3-butanediol dehydrogenase in an expected level, which improves production and accumulation of meso-2,3-butanediol in host strain, and improves the productivity of meso-2,3-butanediol in serratia marcescens.

Genetically modified lactic acid bacteria having a reduced or lacking or enhanced diacetyl reductase activity, acetoin reductase activity and/or butanediol dehydrogenase activity are provided. Such bacteria are used in starter cultures in the production of food products including dairy products where it is desired to have a high content of diacetyl and for reducing or completely removing diacetyl in beverages including beers, fruit juices and certain types of wine, where the presence of diacetyl is undesired.

The invention discloses construction of a high-yield engineering strain for optically pure meso-2,3-butanediol. A construction method comprises the following steps of carrying out codon optimization on nucleotide sequences of an alpha-acetolactic acid synthetase gene, an alpha-acetolactic acid decarboxylase gene and a meso-2,3-butanediol dehydrogenase gene, afterwards, splicing to obtain a gene cluster containing the three genes, then introducing the gene cluster into an expression vector to obtain a polycistronic recombinant plasmid, and finally introducing the recombinant plasmid into a host bacterium E. coli again, so that a high-yield engineering bacterium is obtained. Synthesis raw materials used by the bacterium are wide in sources and low in costs; the strain has no pathogenicity; the strain is high in yield, high in production efficiency and good in stability, has the highest yield which can reach 91.5g/L and the optical purity which can reach 99 percent or above. The invention discloses application of the high-yield engineering strain to the production of the optically pure meso-2,3-butanediol by utilizing cheap cassava meal as a carbon source and utilizing cottonseed protein powder, soybean pulp powder, soybean cake powder or peanut protein powder as a nitrogen source at the same time. The production cost is lowered.

The invention discloses a coding gene of meso-2,3-butanediol dehydrogenase, a recombinant expression vector and recombinant expression transformant with the gene, a preparation method of recombinase, and application of the recombinase as a catalyst in an asymmetrically reducing prochiral dicarbonyl compound for preparing optical activity chiral diols. The meso-2,3-butanediol dehydrogenase comes from Bacillus licheniformis CICIMB0109, can be used as a catalyst for efficiently synthesizing chiral diols, is high in catalytic activity and stereoselectivity, mild in suitable reaction condition and friendly to the environment, and has quite good application and development prospects.

The invention discloses a genetically engineering bacterium capable of producing S-3-hydroxy-butanone as well as a construction method and application thereof. The bacterial strain is classified and named as paenibacillus polymyxa CGMCC 3044-Bud A<->. Bud A is a 2,3-butanediol dehydrogenase gene, and the Bud A gene in P. polymyxa CGMCC 3044 is knocked out through homologous double-crossover to obtain the bacterial strain p. polymyxa CGMCC 3044-Bud A<-1>. The recombinant bacterium constructed by the method can be used for fermenting and synthesizing optically pure S-3-hydroxy-butanone, the optical purity of which can reach 100%; reduction-state byproduct 2,3-butanediol of the 3-hydroxy-butanone is not generated; the bacterial strain can be produced by directly using substrates such as jerusalem artichoke and inulin, glucose and butanedione; the construction method has the advantages of being extensive in culture conditions, convenient and simple to operate and beneficial to large-scale industrial production; and the bacterial strain has high optical purity and is low in production cost.

The invention discloses a method for fermenting to produce acetoin by utilizing a bacillus licheniformis engineered strain. The method comprises the following steps: knocking out glycerol dehydrogenase genes gdh and 2,3-butanediol dehydrogenase genes budC by taking bacillus licheniformis 10-1-A as an original strain, replacing lactic dehydrogenase genes ldh with NADH oxidase genes nox in Thermococcus profundus DT5432, and constructing a bacillus licheniformis engineered strain capable of being used for producing acetoin; taking glucose as a substrate, biologically fermenting the strain, and preparing the acetoin from fermentation liquor. Experiments prove that the engineered strain disclosed by the invention is capable of producing 82.14g/L of acetoin, and the production efficiency reaches2.28g/L per hour. Moreover, the cost in the production process is low, the yield is high, and the method has excellent application value and considerable economic benefits.

The invention discloses an enzyme activity improved 2,3-butanediol dehydrogenase mutant and an establishment method thereof and belongs to the technical field of genetic engineering. According to themutant disclosed by the invention, the 52nd proline is mutated into lysine on the basis of amino acid as shown in SEQ ID No.2. The enzyme activity of the mutant disclosed by the invention is improvedby 68% when being compared with that before mutation, and the industrial application potential of the enzyme is improved.

The invention discloses a method for generating L(+)-acetoin by in-vitro enzyme reaction. The method comprises the following steps: (1) connecting a carrier pET28a with 2,3-butanediol dehydrogenase coding gene bdhA to obtain pET28a-bdhA, and importing escherichia coli, fermenting, purifying, and concentrating to obtain 2,3-butanediol dehydrogenase concentrated solution; connecting a carrier pET28a with NADH oxidase coding gene yodC to obtain pET28a-yodC, and importing the escherichia coli, fermenting, purifying, and concentrating to obtain NADH oxidase concentrated solution; and (2) uniformly mixing the 2,3-butanediol dehydrogenase concentrated solution, the NADH oxidase concentrated solution, meso-2,3-butanediol, NAD+ and FAD+, reacting to obtain the L(+)-acetoin. The method is capable of using the cheap meso-2,3-butanediol as a substrate, and realizing the in-vitro generation of the L(+)-acetoin with high added value. The yield and purity are high.

The invention belongs to the technical field of biology, and particularly relates to a mutant strain for increasing the content of ethanol produced by fermentation of synthesis gas, construction and an application of the mutant strain and a method for increasing the content of ethanol produced by fermentation of synthesis gas of the mutant strain obtained by genetic engineering means. The mutant strain is mutation obtained by deletion or inactivation of 2, 3-butanediol dehydrogenase in clostridium aerovorans. According to the deletion mutant constructed by the invention, the yield of a byproduct 2, 3-butanediol and the proportion of the byproduct 2, 3-butanediol in a total fermentation organic solvent are remarkably reduced under the condition that the normal growth of a strain is hardly influenced. The clostridium yangdaei is taken as an example, the yield of the 2, 3-butanediol is reduced to 2.4 g/L from 16.6 g/L, and the generation of ethanol is basically not influenced. According to the method, the content of the byproduct 2, 3-butanediol in the total fermentation solvent is reduced in a gene deletion manner, and meanwhile, the proportion of ethanol in the total fermentation solvent is increased, so that the separation cost of the fermentation liquor is reduced, and the method has important significance on industrial implementation of fuel ethanol production through synthesis gas fermentation.