Roche Vitamins Inc.

Ajinomoto Co., Ltd.

Kaneka Corporation

Masaru Wada

Sakayu Shimizu

Shigeru Nakamori

Hiroshi Takagi

Yoshihiko Yasohara

Junzo Hasegawa

Noriyuki Kizaki

Michihiko Kataoka

Kazuhiko Yamamoto

Keiko Kita

Hiroshi Kawabata

Hirotada Mori

L-cysteine is produced by culturing anbacterium having L-cysteine producing ability and containing a gene encoding an O-acetylserine sulphydrylase B or MalY regulatory protein that is modified so that cysteine desulfhydrase activity is reduced or eliminated. The bacterium is cultured in a medium to produce and cause accumulation of L-cysteine in the medium, and collecting L-cysteine from the medium.

L-cysteine producing microorganism and a method for producing L-cysteine

L-cysteine is produced by culturing a coryneform bacterium in which intracellular serine acetyltransferase activity is increased by transformation with a gene coding for serine acetyltransferase, such modification of an expression control sequence of a gene coding for serine acetyltransferase that expression of the gene in a cell should be enhanced and for forth, preferably in which L-cysteine decomposition system is further suppressed, in a medium to produce and accumulate L-cysteine in culture and collecting the L-cysteine from the culture.

L-cysteine producing bacterium and method for producing L-cysteine

L-Cysteine is produced by culturing a bacterium belonging to the genushaving an L-cysteine producing ability and modified so that cystathionine-&#x3b2;-lyase activity or cystathionine-&#x3b2;-lyase activity and tryptophanase activity should be reduced or eliminated in a medium to produce and accumulate L-cysteine in the medium and collecting the L-cysteine from the medium.

The present invention is directed to genetic material useful for the preparation of actinol, such as an isolated DNA including a nucleotide sequence coding for an enzyme having levodione reductase activity, a polypeptide encoded by such a DNA, recombinant organisms, and the like. These genetic materials may originate from Corynebacterium, Cellulomonas, Planococcus, Arthrobacter, and the like. The present invention also provides a process for the production of actinol.

Recombinantly producing levodione reductase

A levodione reductase having the following physical properties is provided: molecular weight: from about 142,000 to about 155,000&plusmn;10,000 (consisting of four homologous subunits having a molecular weight of 36,000&plusmn;5,000); co-factor: nicotinamide adenine dinucleotide (AND/NADH); substrate specificity: active on levodione; optimum temperature: about 15&deg; C. to about 20&deg; C. at pH 7.0; optimum pH: 7.5; and activator: K , Cs , Rb , Na and NH . The levodione reductase according to the present invention produces actinol, an important intermediate for the production of zeaxanthin, from levodione. This enzyme may be produced from a microorganism belonging to the genus Corynebacterium, preferably the microorganism AKU 611 (FERM BP-6448) or a functional equivalent, subculture, mutant or variant thereof. Also provided is a process for producing the levodione reductase that includes cultivating a microorganism of the genus Corynebacterium in an aqueous medium under aerobic conditions, disrupting the cells of the microorganism and isolating and purifying the levodione reductase from the cell-free extract. A process for producing actinol from levodione is also provided that includes contacting levodione with levodione reductase in the presence of the reduced form of nicotinamide adenine dinucleotide or a cell-free extract of the microorganism, and then isolating the resulting actinol from the reaction mixture.

Levodione reductase

An enzyme having carbonyl reduction activity of reducing a carbonyl compound asymmetrically to produce an optically active alcohol, a DNA coding the enzyme, a plasmid having the DNA, a transformant which is a cell transformed with the plasmid, and a production method of an optically active alcohol using the enzyme and/or the transformed cell are provided.

Carbonyl reductase enzyme and methods for its use

A process for making (4R, 6R)-4-hydroxy-2,2,6-trimethylcyclohexanone by contacting (6R)-2,2,6-trimethylcyclohexanedione with a microorganism which is selected from microorganisms of the genera Cellulomonas, Corynebacterium, Planococcus and Arthrobacter and which is capable of the selective asymmetric reduction of (6R)-2,2,6-trimethylcyclohexanedione to (4R, 6R)-4-hydroxy-2,2,6-trimethylcyclohexanone, and recovering the resulting (4R, 6R)-4-hydroxy-2,2,6-trimethylcyclohexanone from the reaction mixture. The selective asymmetric reduction can be effected in the presence of a co-factor, such as, nicotinamide adenine dinucleotide (NAD), nicotinamide adenine dinucleotide phosphate (NADP), or said co-factor with glucose and glucose dehydrogenase (GDH), and/or in the presence of a surfactant. The product is useful for the synthesis of carotenoids, such as, zeaxanthin.

Growing community of inventors

San Diego, CA, United States of America

Masaru Wada