Abstract

Several novel bioprocesses that have little or no counterpart in traditional methodology have recently been reported. The stereoselective and enantioselective hydrolysis of sec-alkyl sulfate esters by alkyl sulfatases proceeds with inversion of configuration and furnishes a homochiral product mixture. Haloalcohol dehalogenases were shown to accept various non-natural nucleophiles, such as azide, cyanide and nitrite for the asymmetric opening of epoxides giving rise to the corresponding azido-, cyano-, and nitro-alcohols as non-natural products. Asymmetric carbon-carbon bond formation via the acyloin- and benzoin-reaction was successfully catalyzed in water by novel lyases, such as benzoylformate decarboxylase and benzaldehyde lyase. New methods for the production of chiral nonracemic alpha-L-amino acids and amines were recently reported. Enantioselective stereoinversion of racemic alpha-aryl- and alpha-aryloxycarboxylic acids via epimerase-catalyzed inversion led to a single stereoisomeric product from the racemate.