Mitsubishi Chemical Corporation

Mitsubishi Petrochemical Company Limited

Petroleum Energy Center

Makoto Goto

Hideaki Yukawa

Masato Terasawa

Terukazu Nara

Yasukazu Uchida

Izuru Tokumaru

Hisashi Yamagata

Kazuhisa Hatakeyama

Nobutake Fugono

Fumaric acid is produced by reacting a culture of a microorganism which produces maleate isomerase that exhibits a maximum activity at not less than 50.degree. C. or a treated product thereof with maleic acid in an aqueous solution, and isomerizing maleic acid to produce fumaric acid. L-aspartic acid is produced by reacting both of a culture of a microorganism which produces maleate isomerase or a treated product thereof and a culture of a microorganism which produces aspartase or a treated product thereof with maleic acid and ammonia in an aqueous solution, producing L-aspartic acid from maleic acid and ammonia by enzyme reactions, and recovering L-aspartic acid from the reaction mixture.

Method of producing fumaric acid

The present invention relates to a process for producing L-tryptophan in a single-stage reaction, comprising carrying out an L-tryptophan producing reaction with glycine, formaldehyde and indole as raw materials in an aqueous solution in the presence of microbial cells having serine transhydroxymethylase or a treated products thereof and microbial cells having tryptophan synthase or tryptophanase, or a treated products thereof; and collecting produced L-tryptophan from the reaction solution.

Process for the preparation of L-tryptophan

Fumaric acid is produced by reacting maleic acid in an aqueous solution with a microorganism which has maleate isomerase activity or with a preparation from the microorganism having the maleate isomerase activity, and producing fumaric acid in a reaction solution by enzymatic isomerization of maleic acid carried out under the condition that the dissolved oxygen concentration in the reaction solution is substantially maintained at 4 ppm or less, for example, by sealing the reaction solution with one or more gases selected from N.sub.2, Ar, and He.

Method for producing fumaric acid

There is disclosed a process for preparing indigo which comprises bringing an indigo-producing bacteria belonging to genus Acinetobacter or treated products thereof into contact with an aqueous solution containing at least indole to have indigo formed and accumulated in the aqueous solution; and collecting indigo from the aqueous solution.

Process for preparing indigo

Microorganisms of the genus Pseudomonas containing aspartate beta-decarboxylase at a high level are produced by culturing said microorganism in a medium supplemented with a chelating agent. L-Alanine can be efficiently produced from L-aspartic acid said microorganisms or the treated product thereof.

Process for culturing microorganisms of the genus Pseudomonas and

There is disclosed a process for producing L-alanine by reacting in a single reaction tank, in an aqueous reaction mixture having a pH of 6 to 10 and containing at least one .alpha.-keto acid, fumaric acid or a salt thereof with ammonia or ammonium ions in the presence of two microorganisms having fumarase inactivity.

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Ami, Japan

Makoto Goto