Effect of growth rate on ethanol tolerance of Saccharomyces cerevisiae.
delta 5,7-Sterol-accumulating Saccharomyces cerevisiae cells growing in chemostat at a specific growth rate of 0.075/h exhibited higher ethanol tolerance measured as ethanol-induced death and anaerobic growth inhibition than the cells growing at 0.2/h, the difference being dependent on the carbon-to-nitrogen molar proportion in the medium. The observed difference in sensitivity to ethanol of anaerobic growth between the slowly and rapidly-growing cells was completely reversed as a result of a block in sterol synthesis causing a negligible synthesis of delta 5,7-sterols. Two physiological parameters, budding frequency and membrane composition, evidently affected ethanol tolerance. Differences between the delta 5,7-sterol-synthesizing and deficient strains documented a profound effect of the quality of the sterol present on the physiological state of the cell.
Novotný
C
C
Institute of Microbiology, Czechoslovak Academy of Sciences, Prague.
Flieger
M
M
Panos
J
J
Dolezalová
L
L
D000693:Anaerobiosis / Q000502:physiology; D000431:Ethanol / Q000494:pharmacology*; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism; D013261:Sterols / Q000378:metabolism
D013261:Sterols; D000431:Ethanol