Short-chain dehydrogenase and application of mutant thereof

The invention relates to application of short-chain dehydrogenase and a mutant thereof, and belongs to the technical field of medicines, 2-chloro-1-(3, 4-difluorophenyl) ethanone is used as a cheap and easily available substrate, and (S)-2-chloro-1-(3, 4-difluorophenyl) ethanol is prepared through catalytic asymmetric reduction of the short-chain dehydrogenase or the mutant thereof. According to the method, wild-type short-chain dehydrogenase is designed and modified, a mutant with remarkably improved activity and stereoselectivity is obtained through screening, a coenzyme regeneration system is carried, rapid conversion of 200g/L of a compound I is realized, and meanwhile, the substrate conversion rate is 99.9% or above. The short-chain dehydrogenase with a new source and the mutant of the short-chain dehydrogenase are used for preparing (S)-2-chloro-1-(3, 4-difluorophenyl) ethanol by an enzyme method, and have the characteristics of high space-time conversion rate, mild reaction conditions, environmental fr