Ajinomoto Co., Ltd.

Yosuke Koyama

Takashi Nakamura

Koji Tamura

Harufumi Miwa

Osamu Tosaka

Minoru Tsuruta

Keishi Shimazaki

Tatsuya Nakayama

Yoshio Kawahara

Shigeho Ikeda

Toshimasa Ishii

Hiroe Yoshii

Minoru Yoshimura

Sumio Inoue

Eiko Shimizu

Tatsuya Yoshioka

Koichi Goto

The present invention relates to a method for controlling carbon source concentration in the aerobic cultivation of a microorganism. The substrate carbon source remains at a low level in a cultivation vessel during the culture feeding in aerobic fed-batch, continuous or cell-recycling continuous cultures. This is accomplished by monitoring the increase in pH or dissolved oxygen content in the culture medium and adding the feed solution intermittently into a cultivation vessel at a calculated feed rate using a feed control device controlled by a computer. The present invention further relates to a process for producing L-lysine by fermentation having the advantages over the prior methods, those being improved productivity, higher concentrations of accumulated product, and increased yields of L-lysine.

Process for production of lysine by fermentation

The present invention is a method for aerobically cultivating yeast or bacteria in a culture medium of fed-batch, continuous or cell-recycling continuous cultures, wherein the carbon source concentration in the culture medium is maintained at a constant low level of under g/l. The carbon source concentration is maintained by measuring the carbon consumption of a culture of the yeast or bacteria in a preliminary experiment. The rate is determined between the time the culture is started and a time when the carbon source is exhausted. A feeding time is then determined wherein the activity of the yeast or bacteria in the presence of the carbon source does not change and a volume of the carbon source to be used in a first feeding (So) is set as So=.nu..times.T. Then, in a main culture, a first feeding of a volume of the carbon source (So) is added for the time (T), and the exhaustion of the carbon source is detected as an increase in pH or an increase in concentration of oxygen dissolved in the culture medium. A second feeding of a volume of the carbon source is then added for the time (T), and the feeding rate is determined based on a period (.tau.) before which the second feeding is added as follows:

Method and apparatus for controlling carbon source concentration in

A method for producing L-glutamic acid, comprising inoculating a microorganism having an ability to produce L-glutamic acid, in a liquid medium containing a carbon source and a nitrogen source, conducting continuous L-glutamic acid fermentation in which both a carbon source and a nutrient having an effect of promoting bacterial growth are fed so as to make the microorganism grow, and then collecting L-glutamic acid produced and accumulated in a culture broth.

Method for producing L-glutamic acid by continuous fermentation

A process for producing L-glutamic acid by fermentation is disclosed, which process comprises culturing aerobically in a culture medium a mutant of the genus Brevibacterium or Corynebacterium which has an increased superoxide dismutase activity and is capable of producing L-glutamic acid in the culture medium and recovering the L-glutamic acid. The yield of L-glutamic acid can be increased by using the aforementioned mutants.

Process for producing L-glutamic acid by fermentation

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Saga-ken, Japan

Yosuke Koyama