Roche Vitamins Inc.

Dsm IP Assets B.v.

Taro Miyazaki

Tatsuo Hoshino

Teruhide Sugisawa

Masako Shinjoh

Noribumi Tomiyama

Setsuko Ojima

The present invention relates to a process for the production of vitamin C from L sorbosone using an aldehyde dehydrogenase which is isolated fromDSM 4025 (FERM BP-3812), said enzyme having the following physicochemical properties: (a) molecular weight of 150,000&#xb1;6,000 Da or 230,000&#xb1;9,000 Da (consisting of 2 or 3 homologous subunits, each subunit having a molecular weight of 75,000&#xb1;3,000 Da); (b) substrate specificity as active on aldehyde compounds; (c) Cofactors are pyrroloquinoline quinone and heme c; (d) Optimum pH between 6.4 and 8.2 for vitamin C production from L-sorbosone; and (e) as inhibitors Co, Cu, Fe, Ni, Zn, monoiodoacetate and ethylendiamine tetraacetic acid. The process is performed in the presence of a suitable electron acceptor and the vitamin C isolated from the reaction mixture.

Vitamin C from sorbosone

The present invention relates to a novel DNA which encodes aldehyde dehydrogenase (SNDH), an expression vector containing the DNA and recombinant organisms containing said DNA. Furthermore, the present invention concerns a process for producing recombinant aldehyde dehydrogenase protein and a process for producing L-ascorbic acid (vitamin C) and/or 2-keto-L-gulonic acid (2-KGA) from L-sorbosone by using the recombinant aldehyde dehydrogenase protein or recombinant organisms containing the expression vector. Also provided is a process for the production of 2KGA with a microorganism in which the gene encoding said aldehyde dehydrogenase is disrupted.

Aldehyde dehydrogenase gene

A new aldehyde dehydrogenase having the physico-chemical properties: molecular weight:150,000&#xb1;6,000 or 230,000&#xb1;9,000; substrate specificity active on aldehyde compounds; cofactors:pyrroloquinoline quinone and heme c; optimum pH: 7.0-8.5; and inhibitors: Co, Cu, Fe, Ni, Zn, monoiodoacetate and EDTA, is derived from a microorganism belonging to the genus. Said aldehyde dehydrogenase can be produced by cultivating a microorganism of the genuswhich is capable of producing an aldehyde dehydrogenase having the above properties, in an aqueous nutrient medium under aerobic conditions, disrupting the cells of the microorganism and isolating and purifying the aldehyde dehydrogenase from the cell-free extract of the disrupted cells of the microorganism. 2-Keto-L-gulonic acid (2-KGA) can be produced from L-sorbosone by contacting L-sorbosone with (i) the aldehyde dehydrogenase in the presence of an electron acceptor, (ii) amicroorganism capable of producing the aldehyde dehydrogenase in an aqueous medium under aerobic conditions or (iii) a cell-free extract of said microorganism, and in each case isolating the resulting 2-KGA from the reaction mixture.

Method of making an aldehyde dehydrogenase with gluconobacter

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 new aldehyde dehydrogenase having the physico-chemical properties: molecular weight: 150,000&plusmn;6,000 or 230,000&plusmn;9,000; substrate specificity:active on aldehyde compounds; cofactors:pyrroloquinoline quinone and heme c; optimum pH: 7.0-8.5; and inhibitors: Co,, Cu,, Fe,, Ni,, Zn,, monoiodoacetate and EDTA, is derived from a microorganism belonging to the genus Gluconobacter. Said aldehyde dehydrogenase can be produced by cultivating a microorganism of the genus Gluconobacter which is capable of producing an aldehyde dehydrogenase having the above properties, in an aqueous nutrient medium under aerobic conditions, disrupting the cells of the microorganism and isolating and purifying the aldehyde dehydrogenase from the cell-free extract of the disrupted cells of the microorganism. 2-Keto-L-gulonic acid (2-KGA) can be produced from L-sorbosone by contacting L-sorbosone with (i) the aldehyde dehydrogenase in the presence of an electron acceptor, (ii) a Gluconobacter microorganism capable of producing the aldehyde dehydrogenase in an aqueous medium under aerobic conditions or (iii) a cell-free extract of said microorganism, and in each case isolating the resulting 2-KGA from the reaction mixture.

Growing community of inventors

Fujisawa, Japan

Taro Miyazaki