15 results about "Isopropylmalic acid" patented technology

The invention belongs to the technical field of biology, and relates to an escherichia coli engineering strain for producing L-isoleucine through a methyl malic acid way as well as a construction method and application of the escherichia coli engineering strain. According to the invention, Escherichia coli BW25113 is used as a chassis strain, and a methyl malic acid synthase high-activity mutant gene cimA3.7, an isopropyl malic acid isomerase gene GsleuCD, a 3-isopropyl malic acid dehydrogenase gene AfleuB and a leucine dehydrogenase gene Lsleudh are over-expressed; a methyl malic acid absorption protein gene is over-expressed, and a branched chain amino acid transport system is modified to improve the exosome of the L-isoleucine; all methyl malic acid pathway related genes are integrated to a genome of a chassis strain, and a plasmid-free L-isoleucine production strain is constructed; the copy number of a key gene on a genome is optimized, and the yield of the engineering strain L-isoleucine is increased by introducing a non-oxidative glycolysis approach. The yield of the L-isoleucine after the engineering strain is fermented for 34 hours in a fermentation tank is 56.6 g / L.

The present disclosure relates to the field of bioengineered yeast strains as therapeutic platforms. In particular, engineered strains of yeast brassicae comprising a nucleic acid encoding a modified 3-isopropylmalate dehydrogenase (Leu2) and a therapeutic protein, and methods for treating or preventing a disease or condition in a subject in need thereof.

The invention discloses yarrowia lipolytica engineering bacteria for producing esterified astaxanthin as well as a construction method and application of the yarrowia lipolytica engineering bacteria. According to the invention, acyltransferase ScDGAT2-1 from fission vibrio is integrated in a genome of a yarrowia lipolytica engineering strain DN20, diacylglycerol acyltransferase DGA1 and phosphatidic acid phosphatase PAH1 are knocked out, and the corn oil lipoprotein Oleosin and the acyltransferase ScDGAT2-1 from fission vibrio are subjected to fusion expression, so that the yarrowia lipolytica engineering strain DN20 is obtained. According to the present invention, the Yarrowia lipolytica engineering bacterium capable of producing esterified astaxanthin at a high yield is constructed by using SBT06-005 as a raw material and integrating beta-carotene hydroxylase CrtZ, endogenous truncated 3-hydroxy3-methylglutaryl coenzyme A reductase tHMG1, phytoene synthase CarRP and beta-isopropyl malate dehydrogenase LEU2, and the SBT06-005 can produce 166.6 mg / L esterified astaxanthin and 1097.0 mg / L total astaxanthin in a 5L fermentation tank.

The invention belongs to the technical field of biology, and particularly relates to an isopropyl malic acid synthase mutant and application thereof. The isopropyl malic acid synthase mutant is obtained based on random mutation of an error-prone PCR technology, and the enzyme activity of the isopropyl malic acid synthase mutant is greatly improved; the L-leucine yield of a recombinant strain constructed by the mutant is remarkably improved, and the mutant has a relatively high practical value.

The application discloses tobacco isopropyl malate dehydrase NtIPDS, a coding gene, an RNAi interference carrier and application. The application successfully clones a coding gene of isopropyl malate dehydrase in tobacco, and the nucleotide sequence is as follows: (1) the nucleotide sequence shown in SEQ ID NO. 1; (2) the nucleotide sequence shown in SEQ ID NO. 1 is substituted and / or deleted and / or added with one or more nucleotides and the nucleotide sequence of the same functional protein. Based on the existing tobacco genetic engineering progress and related plant phenotype observation and identification, the NtIPDS gene is deeply researched, and it is found that the NtIPDS gene is related to tobacco chloroplast development and acyl sugar metabolism. After the gene is silenced, the chlorosis plant growth is slow, the chloroplast development is found to be abnormal through transmission electron microscope observation, and meanwhile, it is found that the acyl sugar content of the silenced plant is significantly increased through metabolic detection analysis.

The present invention relates to a novel mutant polypeptide having isopropylmalate synthase activity; and a method for producing L-leucine using the same. L-leucine can be produced in high yield by using the mutant polypeptide according to one embodiment.

The present disclosure relates to an isopropylmalate synthase variant and a method of producing L-leucine using the same.

The invention belongs to the technical field of chemical analysis of tobaccos, and particularly relates to a GC-MS detection method for malic acid derivatives in tobaccos. The GC-MS detection method for the malic acid derivatives in the tobacco comprises the steps that a sample to be detected is extracted and then subjected to a derivatization reaction to obtain a liquid to be detected, gas chromatography-mass spectrometry testing is conducted, detected malic acid is 2-hydroxy-3-isopropyl malic acid and 2-isopropyl malic acid, the temperature of a sample inlet is 290-300 DEG C, programmed heating is adopted, the temperature is kept at 60-70 DEG C for 10-15 min, the temperature is kept at 60-70 DEG C for 20-30 min, and the temperature is kept at 60-70 DEG C for 20-30 min. 2-hydroxy-3-isopropyl malic acid and 2-isopropyl malic acid serve as raw materials, the raw materials are heated to 290-310 DEG C at the heating rate of 5-8 DEG C / min, the temperature is kept for 10-15 min at the temperature of 290-310 DEG C, scanning is conducted in an SRM scanning mode, ion pairs of the 2-hydroxy-3-isopropyl malic acid and the 2-isopropyl malic acid are 191.1 / 73.1 and 73.1 / 45 respectively, the retention time of the 2-hydroxy-3-isopropyl malic acid and the retention time of the 2-isopropyl malic acid are 0.3-0.5 min, and the collision energy is 8-10 eV. Through derivatization reaction after extraction and selection of specific sample introduction temperature, temperature rising program and mass spectrum parameters during gas chromatography-mass spectrometry analysis, the detection method disclosed by the invention has relatively high accuracy and sensitivity.

An engineered strain that optimizes the mannose metabolic pathway and produces high amounts of spinosad is developed. The strain is based on Saccharopolyspora spinosa. manB Genes and leuA Gene blocking, and aceF Gene overexpression is obtained; manB The gene refers to the phosphomannose mutase gene; leuA The gene refers to the 2-isopropylmalate synthase gene; aceF The gene refers to the pyruvate dehydrogenase gene. The present invention starts with the precursor supply pathway of Saccharopolyspora spinosa, takes the mannose metabolic pathway as the optimization object, reduces the competitive utilization of the substrate glucose, and promotes more glucose metabolic flow to the pyruvate metabolic pathway; then reduces the competitive utilization of acetyl-CoA, improves the ability to synthesize acetyl-CoA from pyruvate, increases the accumulation of the precursor substance acetyl-CoA, and finally achieves the promotion of the efficient biosynthesis of spinosad in the engineered strain.

The present application relates to: a novel mutant polypeptide having isopropylmalate synthase activity; and a method for producing L-leucine by using same. L-leucine can be produced at high yield by using the mutant polypeptide according to an embodiment.

The present invention belongs to the field of metabolic engineering, and specifically relates to a 1,2-pentanediol biosynthesis method and a recombinant microorganism for producing 1,2-pentanediol. The synthesis method of the present invention includes the following enzymes: threonine dehydratase, α-isopropylmalate synthase, α-isopropylmalate isomerase, β-isopropylmalate dehydrogenase, 2-oxidocarboxylic acid reductase, acyl CoA transferase, acyl CoA reductase, aldehyde reductase, cinnamic acid acylase, etc., and the above-mentioned enzyme gene encoding plasmid is used to obtain a recombinant microorganism, and the recombinant microorganism is fermented and cultured with an organic carbon source such as glucose to obtain high-yield 1,2-pentanediol. The present invention provides a biological method for synthesizing 1,2-pentanediol, and can significantly increase the yield of 1,2-pentanediol, and has broad application prospects.

This disclosure relates to the field of bioengineered yeast strains as therapeutic platforms. In particular, to genetically modified strains of Saccharomyces bouloidii yeast containing modified 3-isopropylmalate dehydrogenase (Leu2) and nucleic acids encoding therapeutic proteins, as well as methods for treating or preventing diseases or conditions in subjects requiring such treatment.

The present invention relates to the construction and application of a genetically engineered strain capable of realizing the co-production of branched-chain amino acids, and can realize the co-production of branched-chain amino acids (BCAA) such as valine, leucine and isoleucine by fermentation. A genetically engineered strain is obtained by a genetic engineering method, wherein the genetically engineered strain is a synthetic pathway of leucine introduced into an Escherichia coli host cell capable of producing isoleucine and / or valine, and isopropylmalate synthase encoding gene leuAm, isopropylmalate dehydrogenase encoding gene leuB, isopropylmalate dehydratase encoding gene leuCD, aromatic amino acid transaminase gene tyrB and leucine efflux protein gene leuE are expressed to release the feedback inhibition of L-leucine. The co-production of two or three branched-chain amino acids is finally realized, and the co-production process has at least 30% improvement in the utilization rate of overall glucose. The genetically engineered strain described in the present invention has a short fermentation cycle, high yield, high conversion rate, and has a high production application value.

The invention belongs to the technical field of biology, and particularly relates to an isopropyl malic acid synthase mutant and application thereof. The isopropyl malic acid synthase mutant is obtained based on random mutation of an error-prone PCR technology, and the enzyme activity of the isopropyl malic acid synthase mutant is greatly improved; the L-leucine yield of a recombinant strain constructed by the mutant is remarkably improved, and the mutant has a relatively high practical value.

The present invention belongs to the field of biotechnology, and particularly relates to an isopropylmalate synthase mutant and its application. The isopropylmalate synthase mutant is randomly mutated based on the error-prone PCR technology, greatly improving its enzyme activity; the L-leucine yield of the recombinant strain constructed with the mutant is significantly increased, having great practical value.