| 摘要 |
A levodione reductase having the following physico-chemical properties is provided: molecular weight: 142,000 - 155,000 ~ 10.000 (consisting of four homologous subunits having a molecular weight of 36,000 ~ 5,000); co-factor: nicotinamide adenine dinucleotide (NAD/NADH); substrate specificity: active on levodione; optimum temperature: 15 - 20.degree.C at pH 7.0; optimum pH: 7.5; and activator: K+, Cs+, Rb+, Na+ and NH4+. Said levodione reductase, which is capable of producing actinol, an important intermediate for the production of zeaxanthin, from levodione, can be produced from a microorganism belonging to the genus Corynebacterium, preferably the microorganism Corynebacterium aquaticum AKU 611 (FERM BP-6448) or a functional equivalent, subculture, mutant or variant thereof. Further inventive aspects are a process for producing the levodione reductase comprising cultivating a microorganism of the genus Corynebacterium in an aqueous medium under aerobic conditions, disrupting the cells of the microorganism and isolating and purifiying the levodione reductase from the cell-free extract of the disrupted cells of the microorganism, and a process for producing actinol from levodione comprising contacting levodione with the levodione reductase in the presence of the reduced form of nicotinamide adenine dinucleotide or a cell-free extract of said microorganism, and in each case isolating the resulting actinol from the reaction mixture. |
