Ajinomoto Co., Ltd.

Masako Izui

Masakazu Sugimoto

Tsuyoshi Nakamatsu

Atsushi Hayakawa

Yasuhiko Yoshihara

Eiichi Nakano

Masaki Kobayashi

Osamu Kurahashi

Seiko Hirano

Seiko Otsuna

Kenzo Yokozeki

Hisao Ito

Hiroshi Matsui

Mika Moriya

Yukiko Ono

Hiroko Kishino

Yasuhiko Ajinomoto Co Inc Technology Yoshihara

The ability and speed with which a coryneform bacterium can produce L-lysine are improved when the coryneform bacterium contains an aspartokinase in which feedback inhibition by L-lysine and L-threonine is substantially desensitized. This is accomplished by successively enhancing the DNA coding for dihydrodipicolinate reductase, the DNA coding for dihydrodipicolinate synthase, the DNA coding for diaminopimelate decarboxylase, and the DNA coding for diaminopimelate dehydrogenase.

Method of producing L-lysine

The L-lysine-producing ability and the L-lysine-producing speed are improved in a coryneform bacterium harboring an aspartokinase in which feedback inhibition by L-lysine and L-threonine is substantially desensitized, by successively enhancing DNA coding for a dihydrodipicolinate reductase, DNA coding for a dihydrodipicolinate synthase, DNA coding for a diaminopimelate decarboxylase, and DNA coding for a diaminopimelate dehydrogenase.

A gene encoding a protein constituting sucrose PTS of coryneform bacterium is provided by amplifying a region existing downstream from sucrase gene in coryneform bacterium by the cassette-ligation mediated PCR to obtain DNA encoding sucrose PTS enzyme II, which is a protein defined in the following (A) or (B):

Dna encoding sucrose pts enzyme II

A microorganism, which has an ability to produce L-amino acid, especially L-phenylalanine, L-tryptophane, L-tyrosine, L-threonine, or L-isoleucine, in which a phosphoenolpyruvate-producing ability is enhanced, is cultivated in a medium so that the L-amino acid is produced and accumulated in the medium to collect the L-amino acid.

Process for producing L-amino acids

A coryneform bacterium in which a DNA coding for a diaminopimelate decarboxylase and a DNA coding for a diaminopimelate dehydrogenase are enhanced is cultivated in a medium to allow L-lysine to be produced and accumulated in a culture, and L-lysine is collected from the culture.

A method of amplifying a desired gene in a chromosome of a coryneform bacterium, which comprises forming an artificial transposon in which a drug resistance gene and the desired gene are inserted into an insertion sequence of the coryneform bacterium, and introducing said artificial transposon into the coryneform bacterium. In accordance with the method of the present invention, a desired gene can be amplified in a chromosome in coryneform bacteria which are used in the industrial production of amino acids or nucleic acids.

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Kawasaki, Japan

Masako Izui