Ajinomoto Co., Ltd.

Harufumi Miwa

Koji Tamura

Minoru Tsuruta

Shigeru Nakamori

Yasuhiko Yoshihara

Toshimasa Ishii

Takashi Nakamura

Osamu Tosaka

Yosuke Koyama

Minoru Kashiwada

Toshiki Hirose

Manabu Yokomori

Keishi Shimazaki

Tatsuya Nakayama

Yoshitomo Uehara

Hideo Kuronuma

Yoshio Kawahara

Masakazu Sugimoto

Kazuhiko Totsuka

Tsuyoshi Osumi

Wataru Hibino

Yutaka Murakami

Ikuo Goto

Yoshimasa Yahagi

A coryneform bacterium which has enhanced intracellular pyruvate carboxylase activity obtained by increasing copy number of a gene encoding the intracellular pyruvate carboxylase, or by enhancing function of a expression regulatory sequence for the gene, and has L-glutamic acid-producing ability is cultured in a medium so that L-glutamic acid should be produced and accumulated in the culture, and L-glutamic acid is collected from the culture.

Method for producing L-glutamic acid by fermentation

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

The present invention relates to (a) process for producing L-lysine by fermentation which comprises culturing a microorganism having resistance to 4-N-(D-alanyl)-2,4-diamino-2,4-dideoxy-L-arabinose 2,4-dideoxy-L-arabinose or a derivative thereof and belonging to the genus Brevibacterium or the genus Corynebacterium, (b) said bacterium therefore and (c) a method of producing said bacterium.

Process for producing L-lysine by fermentation

Amino acid fermentation is conducted by fermenting bacterial cells in a culture medium in a fermentor and separating fermentation solution withdrawn from the fermentor into a solution containing said bacterial cells and a solution not containing bacterial cells by a cell separator. The solution containing said bacterial cells being circulated from said cell separator to said fermenter by circulating means to perform amino acid fermentation continuously, and bubbles being removed from said fermentation solution by a bubble separator before said fermentation solution is fed to said circulating means and said cell separator.

Process for the production of an amino acid using a fermentation

A basic L-amino acid and an acidic L-amino acid may be concurrently produced by either culturing a basic L-amino acid-producing bacteria under conditions for producing an acidic L-amino acid or mix-culturing a basic L-amino acid-producing bacteria and an acidic L-amino acid-producing bacteria.

Method for concurrent fermentation of basic amino acid and acidic amino

The present invention relates to a fermentation process using a L-lysine-producing microorganism having a resistance to an acyl-lysine, a methylated acyl-lysine or both an acyl-lysine and a methylated acyl-lysine. By the process of the present invention, L-lysine may be produced in high yields providing an improved process that reduces the cost of industrially produced L-lysine.

Process for producing l-lysine by fermentation employing a microorganism

Amino acid fermentation is conducted by fermenting using bacterial cells in a culture medium in a fermentor and separating fermentation solution withdrawn from the fermentor into a solution containing the bacterial cells and a solution not containing bacterial cells by a cell separator, the solution containing the bacterial cells being circulated from the cell separator to the fermenter by a circulating device to perform amino acid fermentation continuously, and bubbles being removed from the fermentation solution by a bubble separator before the fermentation solution is fed to the circulating device and the cell separator.

Apparatus for amino acid fermentation

L-lysine is produced by culturing, in a medium, an L-lysine-producing mutant which belongs to the genus Corynebacterium thermoaminogenes which is capable of growing at 40.degree. C. or higher and which has resistance to S-(2-aminoethyl)-L-cysteine thereby producing and accumulating L-lysine in the culture medium, and collecting L-lysine from the culture medium.

Method for the production of L-lysine employing thermophilic

An apparatus for measuring the presence of microorganisms using fluorescent substances. A number of samples are measured continuously by enclosing the entire reacting and measurement sections within a thermostatically controlled enclosure. A number of samples are placed in containers with reactive liquids and placed in the reacting section of the enclosure. After the specified time within the enclosure, the container is rotated to the measuring section. The remaining liquid is filtered and activating light shined therethrough. The fluorescent light given off is measured to indicate the presence of microorganisms.

Fluorescent analysis apparatus

A fluorescent analyzer including a light source which irradiates a sample with direct light, a first wave selector for passing a predetermined wavelength of light emitted from the light source, a sample cell for holding the sample which is irradiated by light passed by the first wave selector, a second wave selector arranged sidewards of the sample outside a direct path of light from the light source passing straight through the sample for passing light of a second predetermined wavelength emitted from the sample upon irradiation by direct light from the light source, a first light detector for producing a first output signal indicative of the amount of light of the second predetermined wavelength passed by the second wave selector, a second light detector for producing a second output signal indicative of the amount of direct light of the first predetermined wavelength passing straight through the sample, a correction circuit for performing a predetermined correction on the amplitude of the first output signal based on the amplitude of the second output signal to produce a corrected measurement signal, and an indicator for indicating the corrected measurement signal.

Growing community of inventors

Kawasaki, Japan

Harufumi Miwa