6results about How to "Increased space-time yield" patented technology

The invention provides an L-alanine production strain and a construction method and application thereof.The L-alanine production strain is characterized in that a dns gene, a vnp1 gene and a vnp2 gene in a genome of vibrio natriureticus are sequentially knocked out through gene modification with the vibrio natriureticus as an original strain, a series of key competitive pathway genes pflB, lldh, dldh, pta, ackA and adhE are knocked out in order to block an organic acid fermentation pathway of the vibrio natriureticus, and the vibrio natriureticus is obtained; the production of L-alanine is increased, the accumulation of organic acids is reduced, pXtuf-alaD plasmids are transferred to increase the gene copy number, and by cooperating with the ultrafast growth characteristic of the starting strain vibrio natriureticus, the constructed strain has a clear genetic background, shows efficient transformation ability in the subsequent anaerobic production stage, can efficiently produce L-alanine, and has a wide application prospect. Good industrial application prospects are realized.

The invention provides a synthesis method and application of an H-shaped slice high-silicon mordenite molecular sieve, and belongs to the technical field of molecular sieve synthesis and application. The preparation method comprises the following steps: mixing tetraethylammonium hydroxide and long-chain pyrrolidinium salt as template agents with an alkali source, an aluminum source and a seed crystal to form silicon-aluminum sol, aging the silicon-aluminum sol, carrying out a crystallization synthesis reaction, and carrying out ammonium ion exchange, drying and roasting to obtain the H-type high-silicon slice mordenite molecular sieve (MOR). According to the synthesized H-shaped sheet high-silicon mordenite molecular sieve, the Al element is enriched in an eight-membered ring of an MOR zeolite molecular sieve skeleton structure, acid sites which are subjected to side reactions in HMOR can be effectively shielded, and the H-shaped sheet high-silicon mordenite molecular sieve has good catalytic activity and product selectivity when being applied to a reaction for synthesizing methyl acetate through carbonylation.

This invention provides a strain derived from Clostridium difficile (Clostridium difficile) Clostridioides difficile This invention relates to mutants of glutamate dehydrogenase and their applications. The mutants are single-site, two-site, or multi-site mutants of glutamate dehydrogenase. This invention effectively solves the problems of inactivity or low activity of glutamate dehydrogenase in the biocatalytic transformation of 2-carbonyl-4-(hydroxymethylphosphono)butyric acid as a substrate, and provides a continuous chemical method for the synthesis of 2-carbonyl-4-(hydroxymethylphosphono)butyric acid using a microchannel reactor throughout the entire process.

The invention belongs to the technical field of gene engineering, and particularly relates to a nitrile hydratase mutant and application thereof. On the basis of wild type nitrile hydratase from rhodococcus ruber, a mutation site which has a remarkable influence on the activity of the nitrile hydratase is determined by predicting, screening and verifying key active sites, and the nitrile hydratase mutant with improved activity and application of the nitrile hydratase mutant in production of amide compounds are provided. The nitrile hydratase mutant provided by the invention has the advantages that the unit thallus dry weight enzyme activity reaches up to 3649.95 U / g DCW, which is 142.98% higher than that of a wild type; the specific enzyme activity of the purified nitrile hydratase pure enzyme can reach 3589.44 U / mg, and the efficiency of converting nitrile substances into amide products is improved. When the mutant provided by the invention is used for conversion, 2, 6-difluorobenzamide, nicotinamide, cinnamamide, acrylamide and other amide substances can be rapidly produced, and the mutant has higher space-time conversion rate and shorter conversion time.

The invention provides a synthesis method and application of an H-type high-silicon-wafer-shaped MOR zeolite molecular sieve, and belongs to the technical field of synthesis and application of molecular sieves. The method comprises the following steps: adding an aluminum source into a mixed solution containing an alkali source, tetraethylammonium hydroxide, long-chain bipiperidine onium salt and water to form slurry, adding a silicon source and a small-grain MOR zeolite molecular sieve seed crystal into the slurry, uniformly mixing to obtain silicon-aluminum sol, aging the silicon-aluminum sol, carrying out a crystallization synthesis reaction, carrying out ammonium ion exchange on the obtained crystallization product, and drying to obtain the small-grain MOR zeolite molecular sieve. And filtering, washing, drying and roasting to obtain the H-type high-silicon-wafer-shaped MOR zeolite molecular sieve. According to the molecular sieve synthesized by the invention, the Al element is enriched in an eight-membered ring of an MOR zeolite molecular sieve skeleton structure, the quantity of B acid in the eight-membered ring is increased, and the molecular sieve has a small-grain morphology feature structure, can effectively shield acid sites in side reaction in HMOR, is applied to a reaction for synthesizing methyl acetate by carbonylation of dimethyl ether, and has a good application prospect. The catalyst has the advantages of high catalytic activity, good product selectivity, simple preparation process and easy industrial amplification.