92 results about "Lyase Gene" patented technology

The invention discloses an XZ-A26 bacterial strain for producing L-alanine with high yield, which has a preservation number of CGMCC (China General Microbiological Culture Collection Center) No.4036 and has the capacity of generating high-concentration L-alanine through fermentation. The XZ-A26 bacterial strain is constructed by the steps of: integrating an L-alanine dehydrogenase gene on thermophilic fatty bacillus chromosome on lactic dehydrogenase position on an escherichia coli ATCC8739 chromosome, then sequentially knocking out a pyruvate formate lyase gene, an alcohol dehydrogenase gene, an acetokinase gene, a fumaric acid reductase gene and an alanine racemase gene of the escherichia coli chromosome, and then carrying out continuous cell culture in a fermenting tank for obtaining agenetic engineering strain. The invention also relates to a construction method of the XZ-A26 bacterial strain and an application of the XZ-A26 bacterial strain in preparation of the L-alanine. According to the invention, the escherichia coli with the preservation number of CGMCC No.4036 for generating the high-concentration L-alanine through fermentation can be constructed by using a metabolic engineering method, and the yield of the L-alanine generated by using the XZ-A26 bacterial strain reaches up to 115g / L. The XZ-A26 bacterial strain is suitable for industrially producing the L-alanine.

An algin lyase gene algl able to code marine pseudomonads QDA is prepared from the QDA genome DNA library by cloning, and cna be used to prepare the recombinant algin lyase. It can degradate the homopolymannuronic acid to obtain algin oligose. Said recombinant algin lyase features high stability of temp and pH value, and activity, high expression level in colibacillus 24%, and low cost.

An improved hydroxynitrile lyase characterized by having a mutation of substitution of at least one amino acid residue in the amino acid sequence of a wild-type hydroxynitrile lyase with another amino acid and by its hydroxynitrile lyase activity per transformant being higher than the hydroxynitrile lyase activity per transformant into which the wild-type hydroxynitrile lyase gene is introduced; and a method for producing a hydroxynitrile lyase, comprising expressing the improved hydroxynitrile lyase in a host and recovering the improved hydroxynitrile lyase from the resultant culture.

The invention discloses a multifunctional algal polysaccharide lyase gene, multifunctional algal polysaccharide lyase, a genetic engineering bacterium with the multifunctional algal polysaccharide lyase and a method for constructing the genetic engineering bacterium. Nucleotide and amino acid sequences of the multifunctional algal polysaccharide lyase are shown as SEQ ID NO.1 and SEQ ID NO.2. Themethod includes steps of firstly, utilizing DNA (deoxyribonucleic acid) of genomes of marine bacteria as a template and amplifying multifunctional algal polysaccharide lyase gene sequences by the aidof primers; secondly, cloning the multifunctional algal polysaccharide lyase gene into plasmids to obtain recombinant vectors; thirdly, carrying out transformed cloning on the recombinant vectors in hosts; fourthly, carrying out transformed expression on the recombinant vectors in hosts to obtain the multifunctional algal polysaccharide lyase production genetic engineering bacterium. The multifunctional algal polysaccharide lyase gene, the multifunctional algal polysaccharide lyase, the genetic engineering bacterium and the method have the advantage that the multifunctional algal polysaccharide lyase is high in activity for sodium alginate, k-carrageenan, l-carrageenan and agar and can be widely used in the field of chemical engineering, agriculture, food and feed addition, medicines, algahereditary engineering and the like.

The invention relates to a preparation method for high-molecular-weight HA and an engineering bacterium. According to the method, a coding hyaluronic acid lyase gene (hylb) in the genome of Streptococcus zooepidemicus ATCC39920 is knocked out, and a hyaluronic acid lyase gene (hylb)-knocked out vector pSET4s:: hylb:: cmr is constructed. The method provided by the invention subjects a recombinant bacterium in which the hylb gene is knocked out to fermentation and analysis, the molecular weight of HA is measured by using an intrinsic viscosity process, and HA with a molecular weight of 3.9 * 10<6> Da is obtained.

The invention discloses an XZ-A26 bacterial strain for producing L-alanine with high yield, wherein the preservation number is CGMCC No.4036. The XZ-A26 bacterial strain has the ability of fermenting to produce high-concentration L-alanine and is genetic engineering bacteria prepared by integrating the L-alanine dehydrogenase gene on Escherichia Coli chromosome of a lipase gene from Geobacillus Stearothermophilus at the lactic dehydrogenase of Escherichia coli ATCC 8739 chromosome, then sequentially removing a pyruvate formate-lyase gene, an ethanol dehydrogenase gene, an acetokinase gene, a fumarate reductase gene and an alanine racemase gene of the escherichia coli chromosome and then continuously subculturing in a fermentation tank. The invention also relates to a construction method of the bacterial strain and the application of the bacterial strain in preparing the L-alanine. According to the metabolic engineering method, the escherichia coli CGMCC No.4036 capable of fermenting to produce the high-concentration L-alanineis constructed, and the yield of the L-alanine produced by fermenting the bacterial strain is as high as 115g / L. The invention is suitable for the industrial production of L-alanine.

The invention discloses a recombination strain for an enterobacterium and application of the recombination strain for the enterobacterium. The recombination strain provided by the invention is a recombination strain obtained after deactivation of a pyruvate formate-lyase gene in the enterobacterium. As shown by experiments, the amount of by-product CO2 produced during the fermentation process of the recombination strain is obviously reduced and the amount of target products is obviously improved compared with the control. For example, the amount of lactic acid, the amount of succinic acid and the amount of 2, 3-butanediol produced by fermentation of klebsiella oxytoca are respectively improved by 30 percent, 9 percent and 23 percent compared with the control, and the amount of the CO2 produced is only 8.04 percent compared with the control. The recombination strain helps to release the pressure of the greenhouse effect, has important function in the actual industrial production,not only can greatly reduce the yield of the CO2, but also can improve the conversion rate of converting substrates into products, and has wide application prospect.