Ajinomoto Co., Ltd.

Hiroki Kawashima

Osamu Kurahashi

Takayasu Tsuchida

Hitoshi Enei

Shigeru Nakamori

Takashi Nakamura

Tsuyoshi Nakamatsu

Yoshio Kawahara

Hiroshi Izui

Jun Nakamura

Hidetsugu Nakazawa

Haruo Uchibori

Mitsuyoshi Seki

Tatsuya Nakayama

Toshiki Hirose

Inao Oyama

Atsuo Shiraishi

Keiji Ishii

Kayo Moriguchi

Koji Shimazaki

L-Glutamine is produced by culturing a coryneform bacterium which has L-glutamine producing ability and has been modified so that its intracellular glutamine synthetase activity should be enhanced, preferably which has been further modified so that its intracellular glutamate dehydrogenase activity should be enhanced, in a medium to produce and accumulate L-glutamine in the medium and collecting the L-glutamine.

Method for producing L-glutamine by fermentation and L-glutamine producing bacterium

The present invention provides a method of producing L-glutamic acid by fermentation, comprising the steps of culturing a mutant of an L-glutamic acid-producing microorganism of the genus Brevibacterium or Corynebacterium which has lower .alpha.-ketoglutaric acid dehydrogenase activity compared with the wild strains from which said mutant is derived, in a liquid nutrient culture medium containing biotin at a concentration of 10 to 1000 .mu.g/l without adding a biotin activity-suppressing substance thereto; producing and accumulating L-glutamic acid in the culture solution; and recovering L-glutamic acid from said culture solution. According to the method of the present invention, it is possible to industrially produce L-glutamic acid by fermentation in a more economical and efficient manner.

Method of producing L-glutamic acid by fermentation

An apparatus and method for defoaming aerobic fermentation cultures is provided, where the amount of liquid culture medium used is greater than that in conventional aerobic cultures (70% or more of the total capacity of the culture tank) without lowering the productivity of the intended, desired product. In the present apparatus and method, a device for separating vapor from liquid of a foam is in fluid communication with the fermentation tank, a device for condensing residual liquid of the vapor received from the separating device is in fluid communication with the separating device, and a sensor for detecting foams is provided in a location along the fluid communication pathway. In the defoaming apparatus, an optional defoaming device is provided, which may be based on either a rotary body rotating at a high speed by use of an electric motor which beats the foams, or on a centrifugal atomizer. The defoaming device may be provided between the vapor-liquid separating device and the condensing device.

Apparatus for defoaming and controlling aerobic culture fermentation

A process for the production of L-glutamic acid comprising growing microorganisms belonging to the genera Brevibacterium and Corynebacterium that are resisted to prumycin.

Process for producing L-glutamic acid

A method for producing L-phenylalanine by fermentation which comprises aerobically culturing an L-phenylalanine-producing microorganism in an aqueous culture medium and recovering the L-phenylalanine accumulated in the culture medium, the L-phenylalanine-producing microorganism having been constructed by incorporating a recombinant plasmid DNA, into which a DNA fragment controlling resistance to a phenylalanine antagoinst, obtained from a chromosomal DNA of a mutant of the genus Bacillus resistant to the phenylalanine antagonist, has been inserted, into a recipient strain of the genus Bacillus.

Method for producing L-phenylalanine by fermentation

A method for producing L-tryptophan by fermentation in high yields employing a microorganism of the genus Bacillus, which has been constructed by a gene splicing technique by incorporating a recombinant plasmid DNA containing an inserted DNA containing fragment controlling resistance to tryptophan-antagonists into a recipient strain of the genus Bacillus. The incorporated DNA fragment is a mutant of the genus Bacillus which was obtained from resistant to tryptophan-antagonists.

Method for producing L-tryptophan by fermentation

L-Histidine producing microorganisms which have been constructed by introducing a recombinant plasmid DNA inserted on a chromosomal DNA fragment into a recipient strain of the genus Bacillus. These microorganisms are employed to produce L-histidine in higher than normal yields. The recombinant plasmid DNA inserted is obtained from a donor mutant strain of Bacillus subtilis which is resistant to certain L-histidine antagonists. The resistant plasmid confers the properties of the mutant strain upon the recipient Bacillus subtilis to make its high yield of product even higher.

Method for producing L-histidine by fermentation

Growing community of inventors

Kawasaki, Japan

Hiroki Kawashima