30 results about "Isopropylmalic acid" patented technology

Yeast cells with reduced activity of certain enzymes involved in branched chain amino acid biosynthesis in yeast mitochondria are described. Target enzymes include threonine deaminase, isopropylmalate synthase, and optionally branched chain amino acid transaminase.

A method for producing L-leucine, comprising the steps of: culturing a bacterium which is transformed with a DNA coding for an alpha-isopropylmalate synthase densensitized in feedback inhibition by L-leucine, in a culture medium to produce and accumulate L-leucine in the medium, and recovering L-leucine from the medium.

A novel modified polypeptide having an isopropylmalate synthase activity, a polynucleotide encoding the same, a microorganism including the polypeptide, and a method of producing L-leucine by culturing the microorganism.

The invention discloses a high yield L-leucine engineering bacterium and an application of the bacterium.The invention provides a method for preparing a recombinant bacterium. The method comprises the following step of importing an alpha-isopropylmolic acid synthetase mutant encoding gene into a target bacterium to form the recombinant bacterium, wherein an alpha-isopropylmolic acid synthetase mutant is enzyme obtained by mutating 494th arginine of alpha-isopropylmolic acid synthetase into histidine, 497th glycine into aspartic acid and 499th leucine into valine.The high yield L- leucine engineering bacterium, particularly corynebacterium glutamicum MD0032, has higher L-leucine yield than bacterial strains produced at home at present, has a unique identification label and is a L-leucine production strain with a high production and application value.

The invention provides 3-isopropyl malic dehydrogenase C which is extracted from cordyceps sinensis hirsutella sinensis and joins in biological catalysis on 3-isopropyl malic acid to prepare 4-methyl-2-oxo valeric acid, an encoding gene and application of 3-isopropyl malic dehydrogenase C. The amino acid sequence of 3-isopropyl malic dehydrogenase C is as shown in SEQ ID No.1, and the encoding gene is as shown in SEQ ID No.1; the clone DNA (Deoxyribose Nucleic Acid) of the nucleotide sequence can be transferred into engineering bacteria by using methods of transduction, conversion and conjugal transfer, by adjusting the expression of the gene of 3-isopropyl malic dehydrogenase C, the host 3-isopropyl malic dehydrogenase C is high in expression property, an effective method is provided to expand the biological application of 3-isopropyl malic dehydrogenase C, and great application prospects are achieved.

The present invention relates to a mutant, non-naturally occurring or transgenic plant cell comprising: (i) at least one polynucleotide comprising, consisting or consisting essentially of a sequence encoding an isopropylmalate synthase and having at least 60% sequence identity to SEQ ID NO:1 or SEQ ID NO:10 or SEQ ID NO: 12 or SEQ ID NO:14; or (ii) a polypeptide encoded by said polynucleotide(s); or (iii) a polypeptide having at least 60% sequence identity to SEQ ID NO:2 or SEQ ID NO:11 or SEQ ID NO:13 or SEQ ID NO:15; or (iv) a construct, vector or expression vector comprising said polynucleotide sequence(s), optionally wherein said construct, vector or expression vector additionally comprises a promoter comprising, consisting or consisting essentially of the sequence set forth in SEQ ID NO:8 or a variant thereof with at least about 60% identity thereto or a trichome promoter.

The invention relates to a genetic engineering bacterium for producing L-leucine, and application of the genetic engineering bacterium, and belongs to the field of metabolic engineering. The genetic engineering bacterium is obtained by an isopropylmalate synthetase encoding gene leuA[M] capable of relieving L-leucine feedback inhibition through overexpression in a host cell, an acetolactate synthase encoding gene ilvBN[M] capable of relieving L-leucine feedback inhibition, a 3-isopropylmalate dehydrogenase encoding gene leuB and a 3-isopropylmalate dehydratase encoding gene leuCD. Acetohydroxyacid synthase encoded by the leuA[M] relieves the feedback inhibition function of the L-leucine for the acetohydroxyacid synthase, in addition, the activity of the acetohydroxyacid synthase is not obviously lowered than wild leuA encoded isopropylmalate synthetase. The L-leucine genetic engineering bacterium does not have nutritional deficiencies, is quick in growth, and has a short fermentation period, a high yield and a high conversion rate. After fermentation is conducted for 40-44h, the concentration of the L-leucine in fermentation liquor achieves 60.5-69.6g / L.

The invention provides 3-isopropylmalate dehydrogenase B for preparing 4-methyl-2-oxoglutaric acid from cordyceps sinensis Hirsutella sinensis and biologically catalyzed 3-isopropylmalate as well as encoding genes and an application thereof. The 3-isopropylmalate dehydrogenase B has an amino acid sequence shown as SEQ ID No.1, and the encoding genes are shown as SEQ ID No.1. Cloning DNA of a nucleotide sequence provided by the invention can be used for being transferred into engineering bacteria through transduction, transformation and combined transfer methods, the host 3-isopropylmalate dehydrogenase B is endowed with high expression by regulating the expression of the 3-isopropylmalate dehydrogenase B genes, an effective path is provided for widening biological application of the 3-isopropylmalate dehydrogenase B, and the 3-isopropylmalate dehydrogenase B has significant application prospects.

The invention discloses a recombinant strain with a high lipopeptide yield and application thereof, belonging to the technical field of genetic engineering. The recombinant strain is constructed by transforming a 2-isopropylmolic acid synthase gene in a leucine synthesis pathway into an original strain. Compared with the original strain, the recombinant strain which over-expresses a part of the leucine synthesis pathway (2-isopropylmolic acid synthase, 3-isopropylmolic acid dehydrogenase, 3-isopropylmolic acid dehydratase and branched chain amino acid transaminase) has a surfactin yield increased by 55.6%, can be used for production of lipopeptide type biosurfactants, and has a good industrial application prospect. The average lipopeptide yield in fermentation liquor obtained by shake flask fermentation is 13-16 g / L.