Daicel Chemical Industries, Ltd.

Other

Huls Aktiengesellschaft

Sapporo Breweries Limited

Kimitoshi Kawai

Akinobu Matsuyama

Shoichi Takao

Kiyoshi Ishii

Tsuyoshi Morinaga

Michael Czytko

Michio Kosaki

Sadao Kageyama

Kunio Sugawara

D-lactic acid is continuously produced by conducting fermentation in a D-lactic acid-producing medium by using as a seed culture a part of a broth obtained in a previous fermentation step of D-lactic acid and elevating a concentration of said growth-promoter to such an effect that a optical purity of the D-lactic acid may be prevented from decreasing. Instead, air may be used.

Production of high optical purity D-lactic acid

Riboflavin is effectively obtained by culturing in a medium (1) a purine-requiring revertant derived from a riboflavin-producing yeast which belongs to the genus Saccharomyces and has a purine requirement or (2) a riboflavin-producing yeast which belongs to the genus Saccharomyces and is resistant to ammonium ion, and collecting the produced riboflavin.

Process for preparation of riboflavin

Organic acids are prepared by fermentation and then separated from the fermentation broth by means of an electrodialysis. The present process does not require an addition of an alkali. The organic acids are recovered as free acids with high purity and at high yields.

Continuous process for preparing organic acids by fermentation

Riboflavin is obtained directly from the culture in a high yield by cultivating a riboflavin-producing microorganism in a medium using a lower (C.sub.1 to C.sub.4) aliphatic compound, separating riboflavin contained in the culture in the form of heated aqueous solution from solid matters, and crystallizing riboflavin from the heated aqueous solution. Riboflavin is also prepared in a high yield by cultivating a riboflavin-producing yeast belonging to the genus Saccharomyces which has purine requirements and/or resistance to 3-amino-1,2,4-triazole in a medium and collecting riboflavin formed and accumulated in the medium. Moreover, riboflavin is prepared in a high yield even in the presence of iron ions by preliminarily cultivating in liquid a riboflavin-producing yeast belonging to the genus Saccharomyces and then cultivating it in a riboflavin-producing medium containing zinc ions.

Process for the preparation of riboflavin

A new substance having antitumor activity is obtained from an epidermal portion of rice. A substance called RBF-P is obtained by adding ethanol to an aqueous alkaline extract of rice bran, removing the insolubles and precipitating the substance by addition of an acid. This substance comprises an active substance called RBF-PM, which is insoluble in methanol, and an active substance called RBF-X, which is soluble in acetone. The substance RBF-PM is a protein containing extremely little cystine and said protein can suppress solid cancers of mice. The substance RBF-X is a mixture of hexane-solubles such as fatty acids and a hexane-insoluble called RBF-H. A synergistic suppressive action on ascites hepatoma of mice is exhibited by the combination of the RBF-H and the fatty acids.

Growing community of inventors

Hyogo, Japan

Kimitoshi Kawai