Ajinomoto Co., Ltd.

Other

Naoki Usui

Naoto Kato

Kenzo Yokozeki

Masaki Kobayashi

Tsuyoshi Nakamatsu

Toshihide Yukawa

Yoshiteru Hirose

Koji Kubota

Yoko Yamamoto

Jun Kurashige

Joji Takahashi

Tuyoshi Nakamatu

Tsuyoshi Itoyama

Yukio Mitani

The present invention provides a process for producing riboflavin by fermentation, a method for providing microorganisms having an improved riboflavin-producing capability, and strains of microorganisms having improved riboflavin-producing ability. The strains of the present invention belong to the genus Bacillus, have reduced activity of hydrolysing phosphoric acid from 5'-guanylic acid, and have the ability of producing riboflavin. Mutants used in the processes of this invention have an improved ability of producing riboflavin and are capable of producing or accumulating a large amount of riboflavin in the culture medium. The processes of this invention are therefore suitable for producing riboflavin in an effective manner at a low cost.

Process for producing riboflavin by fermentation

The present invention is directed to a process for producing L-aspartyl-L-phenylalanine and/or L-aspartyl-L-phenylalanine diketopiperazine comprising contacting and reacting a culture, cell or a cell-treated product of a microorganism capable of hydrolyzing DKP into AP or capable of performing intramolecular condensation of AP into DKP with DKP and/or AP, in an aqueous medium.

Process for producing L-aspartyl-L-phenylalanine and its diketopiperazine

Lipase is absorbed on a carrier to provide an immobilized lipase preparation containing 0.5 to 8% water by a process that does not require drying. The process is carried out by providing a solution or dispersion of lipase in a liquid solvent, mixing the solution or dispersion of lipase with a carrier to provide a mixture containing 0.5 to 8% water and kneading the mixture to produce the immobilized lipase preparation. The solution or dispersion of lipase may contain an enzyme activity enhancing agent such as a fatty acid or its derivative such as lecithin. By not drying, an immobilized lipase preparation having higher activity is obtained.

Preparation of an immobilized lipase having a low water content without

An immobilized lipase is prepared by adsorbing lipase on a carrier that is capable of retaining 3% or more by weight of water after drying under a reduced pressure of from 0.01 to 1.0 Torr at 70.degree. C. for 60 hours. A cation exchange resin is a preferred carrier and a weakly acidic cation exchange resin is most preferred. The lipase adsorbed on the carrier can be a freeze dried lipase and the resultant carrier-adsorbed lipase is dried. Lecithin may be adsorbed on the carrier as an enzyme activity enhancing agent. The immobilized lipase may also contain a dispersing agent. The immobilized lipase can be used for modifying fats and oils.

Immobilized of lipase on a cation exchange resin

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Kawasaki, Japan

Naoki Usui