Roche Vitamins Inc.

Dsm IP Assets B.v.

Dsm Nutritional Products Inc.

Tatsuya Kiyasu

Tatsuo Hoshino

Yoshie Nagahashi

Yasuhiro Furuichi

Hitoshi Kimura

Masako Shinjoh

Akira Asakura

A process for producing L-ascorbic acid from 2-keto-L-gulonic acid or D-erythorbic acid from 2-keto-D-gluconic acid by contacting 2-keto-L-gulonic acid or 2-keto-D-gluconic acid, respectively, with an enzym having &#x3b1;-amylase activity in solution. The solvent for this reaction can be water, an aqueous alcohol, an organic solvent or a mixture thereof. In each case, the starting material can be in the form of the free acid, the sodium salt, or the calcium salt.

Enzymatic process for the manufacture of L-ascorbic acid and D-erythorbic acid

The present invention relates to the production process of biotin by fermentation using a genetically engineered microorganism, and DNA sequences and vectors to be used in such process.

Biotin biosynthetic genes having biotin synthase activity

Biotin biosynthetic genes

The present invention provides processes for making biotin from desthiobiotin by either contacting desthiobiotin with an enzyme reaction mixture containing bioB gene product and nifU gene product and/or nifS gene product and isolating the biotin or cultivating a microorganism transformed with DNA encoding the bioB gene product, nifU gene product and nifS gene product and isolating the biotin.

Production of biotin

A process for producing L-ascorbic acid (vitamin C) from 2-keto-L-gulonic acid or D-erythorbic acid from 2-keto-D-gluconic acid by contacting 2-keto-L-gulonic acid or 2-keto-D-gluconic acid, respectively, in solution with a lactonase, particularly one belonging to the enzyme class EC 3.1.1.x, according to the classification of Enzyme Nomenclature. The solvent for this reaction can be water, an aqueous alcohol, a non-alcoholic organic solvent or a mixture of an aqueous alcohol and a non-alcoholic organic solvent. The contacting is generally performed in a temperature range of 0.degree. C. to 120.degree. C. and a pH range of 1.5 to 12. In each case the starting material can be in the form of the free acid, the sodium salt, or the calcium salt. The so-produced vitamin C has very well known uses, and the alternatively produced D-erythorbic acid is useful as an antioxidant for food additives.

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Fujisawa, Japan

Tatsuya Kiyasu