Effect of beta-cyclodextrin on production of L-phenylacetyl carbinol by immobilized cells of Saccharomyces cerevisiae.
The rate and extent of microbial transformation of higher concentrations of benzaldehyde substrate to L-phenylacetyl carbinol (L-PAC) by immobilized cells of Saccharomyces cerevisiae ATCC 834 was markedly stimulated by addition of different concentrations of beta-cyclodextrin (BCD) to the fermentation medium. With 0.5, 1.0, and 1.5% BCD in the fermentation medium and cumulative doses of benzaldehyde of 12 and 14 g/L, significantly higher yields of L-PAC were obtained, about one- to twofold that of the yields of the control experiments. The favorable effects of BCD were evident in spite of its presence in stoichiometric concentrations significantly lower than those of benzaldehyde. The presence of BCD also appeared to stimulate microbial growth slightly. Enhanced cellular activity was reflected by faster D-glucose consumption and faster benzaldehyde utilization in the presence of BCD.
Mahmoud
W M
WM
Department of Chemical Engineering and Biotechnology Center, University of Connecticut, Storrs, Connecticut 06268, USA.
El-Sayed
A H
AH
Coughlin
R W
RW