46 results about "Aspartate kinase" patented technology

An L-amino acid is produced by culturing a Methylophilus bacterium which can grow by using methanol as a main carbon source and has L-amino acid-producing ability, for example, a Methylophilus bacterium in which dihydrodipicolinate synthase activity and aspartokinase activity are enhanced by transformation through introduction into cells, of a DNA coding for dihydrodipicolinate synthase that does not suffer feedback inhibition by L-lysine and a DNA coding for aspartokinase that does not suffer feedback inhibition by L-lysine, or a Methylophilus bacterium made to be casamino acid auxotrophic, in a medium containing methanol as a main carbon source, to produce and accumulate an L-amino acid in culture, and collecting the L-amino acid from the culture.

Disclosed is a strain of Escherichia sp., capable of producing O-acetyl homoserine in high yield, with the introduction and enhancement therein of the activity of: homoserine acetyl transferase, aspartokinase and homoserine dehydrogenase; and at least one enzyme selected from a group consisting of phosphoenolpyruvate carboxylase, aspartate aminotransferase and aspartate semi-aldehyde dehydrogenase. Also, a method of producing O-acetyl homoserine using the strain is provided.

This invention relates to four chimeric genes, a first encoding lysine-insensitive aspartokinase (AK), which is operably linked to a plant chloroplast transit sequence, a second encoding lysine-insensitive dihydrodipicolinic acid synthase (DHDPS), which is operably linked to a plant chloroplast transit sequence, a third encoding a lysine-rich protein, and a fourth encoding a plant lysine ketoglutarate reductase, all operably linked to plant seed-specific regulatory sequences. Methods for their use to produce increased levels of lysine or threonine in the seeds of transformed plants are provided. Also provided are transformed plants wherein the seeds accumulate lysine or threonine to higher levels than untransformed plants.

Disclosed are a nucleic acid molecule of Corynebacterium glutamicum origin, having an improved promoter activity, which is operably linked to operon encoding aspartate kinase and aspartate semialdehyde dehydrogense, a vector containing the same, a transformant transformed with the vector, and a method for the production of L-lysine using the transformant.

The invention discloses construction and applications of a corynebacterium glutamicum mutant strain for producing L-homoserine, and belongs to the technical field of fermentation engineering. Corynebacterium glutamicum ATCC 13032 is taken as a starting strain to knock out regulatory protein McbR, homoserine kinase, transport protein MetD, phosphoenolpyruvate carboxykinase; the expression of isocitrate dehydrogenase is down regulated; transport protein BrnFE, aspartic semialdehyde dehydrogenase and homoserine dehydrogenase are overexpressed; and the expression of aspartate kinase, pyruvate carboxylase and the aspartate kinase I derived from escherichia coli are enhanced. Shake flask culture can be performed on the mutant strain for 48 h, and the yield of L-homoserine can reach 8.8 g/L.

The present invention discloses a genetically engineered bacterium of corynebacterium glutamicum producing L-isoleucine. ddh gene encoding diaminopimelate dehydrogenase is knocked out in a genome of astarting strain. A nucleotide sequence of the ddh gene is shown as SEQ ID No:2; a lysC operon encoding an aspartokinase is inserted, the lysC operon contains a lysC mutant gene, a 5'-end promoter anda 3' end termination thereof, and a nucleotide sequence of the lysC mutant gene is shown as SEQ ID No:1; and besides, the starting strain is C. glutamicum H5 delta argG delta alaT::ilvC with a preservation number of CCTCC NO:M2016609. The present invention also discloses a preparation method and an application of the genetically engineered bacterium. The production of the L-isoleucine by the genetically engineered bacterium is increased by 5%, synthesis of a by-product lysine of a metabolic branch is reduced by 45.24%, production cost is lowered, and the genetically engineered bacterium has abroad industrial application prospect.

The present invention provides a double gene construct which includes a nucleic acid sequence with a code having active enzyme of aspartokinase (AK) and a nucleic sequence with a code having active enzyme of dihydropyridine dicarboxylic acid synthase. The construct can differently express two genes in plant or part of plant, and can generate lysine and threonine with a level more than five times of the level of wild amino acid.

Process for the production of -lysine by constructing a recombinant microorganism which has a deregulated lysine 2,3-aminomutase gene and at least one deregulated gene selected from the group (i) which consists of aspartokinase, aspartatesemialdehyde dehydrogenase, dihydrodipicolinate synthase, dihydrodipicolinate reductase, tetrahydrodipicolinate succinylase, succinyl-amino-ketopimelate transaminase, succinyl-diamino-pimelate desuccinylase, diaminopimelate epimerase, diamino-pimelate dehydrogenase, arginyl-tRNA synthetase, diaminopimelate decarboxylase, pyruvate carboxylase, phosphoenolpyruvate carboxylase, glucose-6-phosphate dehydrogenase, transketolase, transaldolase, 6-phosphogluconolactonase, fructose 1,6-biphosphatase, homoserine dehydrogenase, phophoenolpyruvate carboxykinase, succinyl-CoA synthetase, methylmalonyl-CoA mutase, provided that if aspartokinase is deregulated as gene (i) at least a second gene (i) other than aspartokinase has to be deregulated, and cultivating said microorganism.

The invention relates to a method for constructing recombinant escherichia coli. The method comprises the following steps: knocking out the coding gene lysC of aspartokinase, the coding gene panC of pantothenate synthetase and the coding gene ptsG of glucose transporter EIICBGlc in the escherichia coli; and overexpressing the panD gene with a PL promoter to obtain the recombinant escherichia coli. The invention further provides a method for producing beta-alanine by fermenting the recombinant escherichia coli constructed by the method. The recombinant escherichia coli constructed by the method is used for fed-batch fermentation in an improved inorganic salt culture medium, and has a yield of beta-alanine being 18.4g/L and a production strength being 0.61g/L.h, but the yield of beta-alanine of escherichia coli B0016-050 which is not improved by the method is only 5.2mg/L.

A method for producing L-threonine using a microorganism is provided. In the method, additional one or more copies of each of the phosphoenolpyruvate carboxylase (ppc) gene and the threonine operon are integrated into a particular site of the chromosomal DNA of a microorganism, while its inherent ppc gene and threonine operon remain. Accordingly, two or more ppc genes and threonine operons are included in the chromosomal DNA of the microorganism to thereby enhance the expression of the ppc gene encoding an enzyme to convert phosphoenolpyruvate to a threonine biosynthesis precursor, oxaloacetete, and the genes encoding enzymes involved in the synthetic pathway of threonine from oxaloacetate, including thrA (aspartokinasel-homoserine dehydrogenase), thrB (homoserine kinase), and thrC (threonine synthase), thereby markedly increasing L-threonine productivity.

The present invention relates to a transgenic plant comprising one or more plant cells transformed with exogenous nucleic acid encoding a Dunaliella salt-inducible or salt-responsive protein selected from the group consisting of elongation initiation factor 3 (eIF3), NADPH dependent quinone reductase (QOR), aldo-keto reductase (AKR), bifunctional aspartate kinase-homoserine reductase (AK-HSD) and mitochondrial import membrane translocase subunit (TIM9), or a fragment, homolog or variant thereof. The transgenic plant has increased tolerance to salt as compared to a corresponding non-transgenic plant. The present invention further relates to nucleic acids, vectors and constructs encoding the Dunaliella salt-inducible or salt-responsive proteins, and to a method of producing a transgenic plant having an increased tolerance to salt, a method of modifying a plant capacity to survive salt shock, and a method of modifying plant recovery after exposure to salt stress, by introducing the nucleic acids, constructs and/or vectors into one or more cells of the plant.

A coryneform bacterium harboring an aspartokinase in which feedback inhibition by L-lysine and L-threonine is substantially desensitized, and comprising an enhanced DNA sequence coding for a dihydrodipicolinate reductase, an enhanced DNA sequence coding for dihydropicolinate reductase, an enhance DNA sequence coding for dihydropicolinate synthase, an enhanced DNA sequence coding for diaminopimelate decarboxylase and an enhanced DNA sequence coding for aspartate aminotransferase; a method for producing L-lysine comprising the steps of cultivating the coryneform bacterium in an appropriate medium to allow L-lysine to be produced and accumulated in a culture of the bacterium, and collecting L-lysine from the culture; and a recombinant DNA usable for production of the coryneform bacterium.

The invention discloses a method for culturing a transgenic alfalfa with high sulfur-containing amino acid content and special materials thereof. The method for culturing transgenic alfalfa with changed amino acid content provided by the invention introduces aspartokinase encoding gene and adenylylsulfate reductase encoding gene into receptor alfalfa to obtain transgenic alfalfa with amino acid content changed. The aspartokinase is a protein shown as 65-512th site in an amino acid sequence SEQ ID No.2; and the adenylylsulfate reductase is a protein shown as 65-330th in an amino acid sequence SEQ ID No.4. The methionine content of the transgenic alfalfa with changed amino acid content cultivated by the invention is significantly higher than namely 1.5 times of that of the receptor alfalfa of an untransformed Baoding alfalfa (wild type); cysteine content of a transgenic pCAMBIAK-APR line is significantly higher than namely 1.2 times that of the wild type; aspartic acid content of a transgenic pCAMBIAK-APR line is significantly higher than namely 1.4 times that of the wild type; and lysine content of a transgenic pCAMBIAK-APR line is significantly higher than namely 1.5 times that of the wild type.

A method for producing ectoine by fermenting recombinant Corynebacterium glutamicum. The recombinant Corynebacterium glutamicum is obtained by overexpressing, in Corynebacterium glutamicum, an aspartokinase gene lysC of which feedback inhibition is relieved, then replacing the promoter of the dihydrodipicolinate synthase in the recombinant bacterium to attenuate the activity of the dihydropyrimidine dicarboxylic acid synthase, and then transforming the recombinant bacterium with the ectoine synthetic path related gene ectABC. The recombinant Corynebacterium glutamicum can be fermented using different cheap raw materials under a low salt condition to produce ectoine, and use cheap corn slurry instead of expensive yeast powder as a nutritional component, so as to further reduce the costs of the raw materials. In addition, the recombinant Corynebacterium glutamicum solves the biosafety problem, simplifies the post-extraction process, and has a good market application prospect.