Towards a large-scale asymmetric reduction process with isolated enzymes:: Expression of an (S)-alcohol dehydrogenase in E-coli and studies on the synthetic potential of this biocatalyst

An NAD-dependent and widely applicable (S)-alcohol dehydrogenase is isolated and described as a novel enzyme. It is expressed in an E. coli strain with a high production potential. The application of this enzyme in asymmetric biocatalytic reduction is presented as well. This enzyme shows a broad substrate range comprising aliphatic and aromatic ketones as well as beta-keto esters. The synthetic application of this new (S)-alcohol dehydrogenase led to optically active alcohols in high conversion rates accompanied by enantioselectivities of up to > 99% ee. Compared to the wild-type enzyme significant advantages are observed besides the improved availability, such as a high enantioselectivity independent of the reaction time. Furthermore, the alcohol dehydrogenase was cloned and successfully overexpressed in E. coli resulting in a biocatalyst with a potential to be available on technical scale in the future. The development of a large-scale available and widely applicable (S)alcohol dehydrogenase is one prerequisite to use isolated enzymes for asymmetric reduction processes as a valuable tool.