Asymmetric reduction of ketones with enzymes from acetic acid bacteria

Six strains of acetic acid bacteria were evaluated with respect to their capability to catalyze the stereoselective reduction of ketones. The cells were permeabilized before the bioconversions. The best strains were Gluconobacter oxydans DSM 50049 and Acetobacter aceti DSM 2002. Using either of these two strains it was possible to reduce all 12 ketones to (S)-alcohols with an enantiomeric excess of ≥94 %. The highest level of enzymatic activity was found in Acetobacter aceti DSM 2002