ABSTRACT
This chapter focuses on important chiral building blocks for pharmaceuticals synthesized by those prominent ADHs from Lactobacillus and Rhodococcus. A pair of enantiomers has the same structural, physical, and chemical characteristics, but the respective (R) and (S) enantiomers rotate the plane of linear polarized light in different directions. The separation of both enantiomers from a racemic mixture by chiral chromatography or chiral resolution as required after chemical synthesis is cumbersome and costly. Numerous natural and modified ADHs are available for the production of different enantiopure alcohols, for which they are used as isolated or whole cell biocatalysts. Higher enzyme concentrations and activities compared to wild-type cells can be reached using Escherichia coli overexpression strains, which are frequently used for Lactobacillus and Rhodococcus ADHs. Enzymatic cascades, combining two or more enzymatic reactions, can result in higher yields, spend fewer chemicals, and save time, especially if unstable intermediates take part.
