High-yield Production of Optically Active 1,2-Diols from the Corresponding Racemates by Microbial Stereoinversion

A novel method for producing optically active 1,2-diols by microbial Stereoinversion was developed. It was found that some microorganisms could convert only (R)-1,2-pentanediol in the racemate to the (S)-enantiomer. Candida parapsilosis produced 27.9 g/l of (S)-1,2-pentanediol from 30 g/l of the racemate in 24 hr of reaction (molar yield 93%, enantiomeric excess 100%). This Stereoinversion proceeded via oxidation of (R)-1,2-pentanediol to 1-hydroxy-2-pentanone by an NAD+-linked (R)-specific alcohol dehydrogenase and reduction of 1-hydroxy-2-pentanone to (S)-1,2-pentanediol by an NADPH-linked (S)-specific 2-keto-1-alcohol reductase. This microbial stereo-inversion was applicable to ten 1,2-diols. Optically active 1,2-diols prepared by the reaction had the same configuration at the chiral center.