[Cloning, expression and characterization of chiral alcohol dehydrogenase from Rhodococcus erythropolis ATCC 4277].

We characterized alcohol dehydrogenase from Rhodococcus erytropolis to catalyze ketoesters or ketones. We cloned alcohol dehydrogenase gene (adh) of 1047 bp from Rhodococcus erythropolis ATCC 4277, inserted the open reading frame of adh into vector pET-22b(+) and expressed in auto-inducing media for 24 h at 15 degrees C. The enzyme activity was determined at 30 degrees C using acetophenone as substrate. Under the above conditions, the specific enzyme activity of crude extract was 2.6 U/mg. The optimal pH was between 6.0 and 6.5 and the enzyme can survived up to 60 degrees C. After incubation at 60 degrees C for 5 h, 80% enzyme activity remained. The optimal substrate among beta-ketoesters examined was ethyl acetoaetate. Ethyl 4-chloroacetoacetate was catalyzed by whole cell in aqueous phase. After chiral liquid chromatography, the product showed (R)-enantioselective. The study shows that the enzyme might have potential in beta-ketoesters transformation on industrial scale.