Ajinomoto Co., Ltd.

Yoshiya Gunji

Hisashi Yasueda

Shinichi Sugimoto

Takuji Ueda

Yuji Joe

Yuta Nakai

Rie Takikawa

Hisao Ito

Yoshio Kawahara

Seiko Hirano

Nobuharu Tsujimoto

Megumi Shimaoka

Mikiko Yamaguchi

Reiko Hirai

Yuri Miyata

Manami Oba

L-amino acids are produced by culturing a microorganism which has an ability to produce the L-amino acid, but has been modified so that expression of the ybjE gene has been enhanced. The L-amino acid is collected from the culture medium or from the microorganism.

L-amino acid-producing microorganism and method for producing L-amino acid

A method for production of L-lysine is provided which includes the steps of cultivating a methanol-utilizing bacterium in a culture medium to produce and accumulate L-lysine in the culture medium and collecting the L-lysine from the culture medium, wherein the methanol-utilizing bacterium contains DNA encoding dihydrodipicolinate synthetase which is desensitized to feedback inhibition by L-lysine and DNA encoding a LysE protein that can enhance the excretion of L-lysine out of the methanol-utilizing bacterium, and the bacterium is modified so as to increase the intracellular activities of diaminopimelic acid dehydrogenase, diaminopimelic acid decarboxylase, dihydrodipicolinic acid reductase and aspartate-semialdehyde dehydrogenase.

Method for production of L-lysine using methanol-utilizing bacterium

A DNA encoding a variant of a protein having a loop region and six hydrophobic helixes which is involved in excretion of L-lysine to outside of a cell is described, wherein the DNA encodes a mutant protein which does not contain the loop region that is present in the wild-type protein. The mutant protein facilitates excretion of L-lysine, L-arginine, or both to the outside of the cell of a methanol assimilating bacterium when the DNA is introduced into the bacterium. Specifically, lysE24 is introduced into a methanol assimilating bacterium such asbacteria which results in improved L-amino acid productivity, especially production of L-lysine and L-arginine.

Method for producing L-lysine or L-arginine by using methanol assimilating bacterium

A DNA encoding for a mutant of LysE protein, or a homologous protein thereof, of a coryneform bacterium, wherein the mutant, when introduced into a methanol-assimilating bacterium imparts resistance to L-lysine analogue. The DNA encoding for a mutant of LysE protein, or a homologous protein thereof, is introduced into a methanol-assimilating bacterium to improve L-lysine and L-arginine productivity of the methanol-assimilating bacterium.

Method for producing L-amino acid using methylotroph

A DNA encoding a variant of a protein, the protein having a loop region and six hydrophobic helices and involved in secretion of L-lysine to the outside of a cell, wherein the DNA encodes a variant of a protein not containing the loop region and facilitates secretion of L-lysine, L-arginine or both of these L-amino acids to the outside of a methanol-assimilating bacterium when the DNA is introduced into the bacterium, specifically lysE24, is introduced into abacteria to improve L-amino acid productivity, especially L-lysine and L-arginine productivities.

Method for producing L-lysine or L-arginine by using methanol-assimilating bacterium

L-Arginine is produced by culturing a microorganism which has L-arginine producing ability and has been modified so that expression of lysE gene should be enhanced, such a microorganism further modified so that an arginine repressor should not function normally, or such a microorganism further modified so that intracellular activity of an enzyme in L-arginine biosynthetic pathway should be enhanced in a medium to produce and accumulate L-arginine in the medium and collecting the L-arginine from the medium.

Method for producing L-arginine

An L-amino acid is produced by culturing abacterium which can grow by using methanol as a main carbon source and has L-amino acid-producing ability, for example, abacterium 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 abacterium 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.

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The present invention describes a method for producing an L-amino acid comprising culturing a microorganism having an ability to produce an L-amino acid in a medium, whereby the L-amino acid accumulates in the medium, and collecting the L-amino acid from the medium, whereby said microorganism comprises a methanol-utilizing bacterium having the Entner-Doudoroff pathway in which 6-phosphogluconate dehydratase activity and/or 2-keto-3-deoxy-6-phosphogluconate aldolase activity is enhanced.

A DNA encoding a variant of a protein, having a loop region and six hydrophobic helixes and involved in excretion of L-lysine to outside of a cell, wherein the DNA encodes a mutant protein not containing the loop region that is contained in a wild-type protein and facilitates excretion of L-lysine, L-arginine or both of these L-amino acids to outside of a cell of a methanol assimilating bacterium when the DNA is introduced into the bacterium, specifically lysE24, is introduced into a methanol assimilating bacterium such asbacteria to improve L-amino acid productivity, especially L-lysine and L-arginine productivities.

A novel insertion sequence, which has been found in the sMMO gene coding for methane monooxygenase of methane-assimilating bacterium,NCIMB 11132 strain, and has inverted repeat sequences consisting of a sequence of the nucleotide numbers 5-19 of SEQ ID NO: 1 at the both ends, can be utilized as effective means for genetic analysis including creation of insertion mutant strains, gene mapping, promoter searching, insertion of genetic information into chromosomal DNA, disruption of specific gene and the like, or utilized for improving methane-assimilating bacteria by chromosomal genetic engineering techniques.

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Kawasaki, Japan

Yoshiya Gunji