Research Association for Utilization of Light Oil

Mitsubishi Petrochemical Company Limited

Mitsunobu Shimazu

Hideaki Yukawa

Masato Terasawa

Fuzio Endo

Terukazu Nara

Yasurou Kurusu

Yukie Satoo

Keiko Kohama

Makiko Fukushima

A method of selectively inhibiting pyruvic acid decomposition activity in microorganism cells containing tryptophanase or a treated product thereof, which comprises heat-treating said cells or the treated product thereof in the presence of an ammonium ion.

Method of treating microorganism cells containing tryptophanase or

A method for producing L-threonine, which comprises subjecting at least L- or DL-aspartic acid or a salt thereof to enzymatic reaction according to the reaction system not accompanied with growth of microorganism cells in an aqueous solution in the presence of a microorganism and collecting L-threonine formed, wherein the microorganism is a biotin-requiring microorganism for the growth belonging to coryneform bacterium; a plasmid comprising a DNA fragment containing at least a gene encoding biosynthesis of threonine which can be expressed within a biotin-requiring microorganism cell for the growth belonging to coryneform bacterium and a DNA fragment containing a gene encoding autonomous replication within coryneform bacterium cell; and a biotin-requiring microorganism for the growth belonging to coryneform bacterium which has been transformed with the plasmid described above, both of which are employed in the present method. According to the present invention, L-threonine can be produced with good yield, and further since production management becomes extremely easy without requiring cumbersome operation such as sterilization of the medium, etc. as in the fermentation method, L-threonine can be produced inexpensively in industry.

Method for producing L-threonine, and plasmid and microorganism employed

A method of culturing an amino acid racemaseproducing microorganism of the genus Pseudomonas, which comprising culturing said microorganism in a culture medium containing at least one compound selected from the group consisting of glycerol, ethanol, tartaric acid, fumaric acid and succinic acid as a carbon source, and recovering microorganism cells containing the amino acid racemase in an increased amount.

Method of culturing amino acid racemase-producing microorganism of genus

Growing community of inventors

Ami, Japan

Mitsunobu Shimazu