LARGE-SCALE PREPARATION OF (R)-1,2-PROPANEDIOL THROUGH BAKER YEAST-MEDIATED BIOREDUCTION

A procedure for the preparation of (R)-1,2-propanediol on a large scal e by baker's yeast-mediated bioreduction of acetol using ethanol as an energy source is reported. The bioreduction, catalyzed by NADH-depend ent oxidoreductase, was effectively performed using a bubble-column re actor with fed-batch operation. When the reactor with 10 l of medium w as bubbled at an aeration rate of 3 l/min, the final reaction medium c ontained 4 %(w/w) (R)-1,2-propanediol with >98% enantiomeric excess.