CONTINUOUS PROCESS FOR LARGE-SCALE PREPARATION OF CHIRAL ALCOHOLS WITH BAKERS-YEAST IMMOBILIZED ON CHRYSOTILE FIBERS

Bioreductions of prochiral ketones in a continuous process were carrie d out in a Packed-bed-reactor with baker's yeast (Saccharomyces cerevi siae) immobilized on chrysotile fibers (IMBY). The performance of the reactor was observed for 30 days, under a constant dilution rate of 1. 7 x 10(-1) h(-1) using ethylbenzoylformate as substrate. The steady st ate showed 2.9 x 10(-2) g l(-1) h(-1) of productivity, 50% chemical yi eld, and 90% ee (enantiometric excess). Using ethylacetoacetate at the same dilution rate for 8 days, the steady state showed 65% chemical y ield and 95% ee. No significant change on the IMBY integrity was obser ved. The results show that chrysotile is an excellent carrier for immo bilization of baker's yeast (BY) cells to be used in the continuous pr ocess of bioreduction (C) 1998 Elsevier Science B.V. All rights reserv ed.