Roche Vitamins Inc.

Hoffmann-la Roche Inc.

Setsuko Ojima

Tatsuo Hoshino

Masako Shinjoh

Noribumi Tomiyama

Taro Miyazaki

Teruhide Sugisawa

Akira Asakura

Peter Karl Matzinger

The present invention is directed to a recombinant enzymes having alcohol and aldehyde dehydrogenase activity which comprises one or mom recombinant polypeptides selected from the group consisting of polypeptides which are identified by SEQ ID NO 5, SEQ ID NO 6, SEQ ID NO 7, SEQ ID NO 8 and chimeric recombinant polypeptides that are a chimeric combination of at least two of the following amino acid sequences identified by SEQ ID NO 5, SEQ ID NO 6, SEQ ID NO 7, SEQ ID NO 8 and functional derivatives of the polypeptides identified above which contain addition, insertion, deletion and/or substitution of one or more amino acid residues, wherein said enzymatic polypeptides have said alcohol and aldehyde dehydrogenase activity. DNA molecules encoding the recombinant polypeptides, vectors comprising such DNA molecules, host cells transformed by such vectors and processes for the production of such recombinant enzymes are provided. Furthermore the recombinant enzymes having alcohol and aldehyde dehydrogenase activity are used for obtaining aldehydes, ketones or carboxylic acids, and specifically, 2-keto-L-gulonic acid an intermediate for the production of L-ascorbic acid (vitamin C).

Alcohol/aldehyde dehydrogenase

Polynucleotides encoding proteins with D-sorbitol dehydrogenase activity or which function to activate D-sorbitol dehydrogenase proteins, in vivo, vectors and recombinant organisms which contain such polynucleotides, and methods of making D-sorbitol dehydrogenase and L-sorbose.

D-sorbitol dehydrogenase gene

A D-sorbitol dehydrogenase in homogenous form, which catalyzes the oxidation of D-sorbitol to L-sorbose, has a molecular structure consisting of homologous subunits of molecular weight 79,000.+-.5,000 each, a substrate specificity for polyols and an optimum pH of 6.0-7.0. Said D-sorbitol dehydrogenase is producible by a process comprising cultivating a microorganism belonging to the genus Gluconobacter or Acetobacter, or a mutant or variant thereof, which is capable of producing the D-sorbitol dehydrogenase in the cells and isolating it from the cells, e.g. by disrupting the cells and isolation from cell-free extract of the disrupted cells. The so-isolated D-sorbitol dehydrogenase is useful for catalyzing the oxidation of D-sorbitol to L-sorbose, the latter being an important intermediate for the production of vitamin C.

D-sorbitol dehydrogenase

The present invention concerns a novel process for the microbiological manufacture of L-ascorbic acid from L-gulono-gamma-lactone, a process for preparing the enzyme being responsible for the microbiological oxidation of L-gulono-gamma-lactone, and said enzyme as a homogeneous protein, which is a L-gulono-gamma-lactone dehydrogenase.

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Fujisawa, Japan

Setsuko Ojima