Large-scale production of chiral alcohols with bakers' yeast was effec
tively performed by examining the regeneration system of nicotineamide
coenzymes in cells. First, a new procedure for the asymmetric reducti
on of prochiral ketones was developed, based on the use of ethanol ins
tead of carbohydrate as the energy source for NAD(P)H regeneration. In
the asymmetric reduction of ethyl acetoacetate (EA), both the yield a
nd the optical purity of the product, (S)-ethyl 3-hydroxybutanoate (E
3-HB), were considerably improved by applying fed-batch operation to t
he new procedure. (S)-E 3-HB with >99% enantiomeric excess was effecti
vely prepared on a large scale using a bubble-column reactor. Also, ac
etol was reduced to (R)-propylene glycol (PG), a useful chiral buildin
g block, in the same manner. A total scheme for NAD(P)H regeneration f
rom NAD(P))(+) through the oxidative pathway of ethanol was proposed.
The relationship between the condition of the oxygen supply and the ef
ficiency (V-substrate/V-EtOH) was evaluated. Next, an enantioselective
oxidation for preparing other chiral alcohols such as (S)-PG was deve
loped. Treatment of a racemic 1,2-alkanediol with bakers' yeast follow
ed by removal of the oxidation product, 1-hydroxy-2-alkanone, affords
(S)-1,2-alkanediol. The outline of the oxidation, especially the relat
ionship to oxygen transfer for regenerating NAD(+) from NADH, was esti
mated. Finally, the microbial resolution of racemic 1,2-alkanediols wa
s performed on a large scale by repeating the procedures with bakers'
yeast, the oxidative resolution of racemic 1,2-alkanediols followed by
the asymmetric reduction of the oxidation products.