RT Journal Article SR Electronic(1) A1 Verduyn, Cornelis A1 Postma, Erik A1 Scheffers, W. Alexander A1 van Dijken, Johannes P.YR 1990 T1 Physiology of Saccharomyces Cerevisiae in Anaerobic Glucose-Limited Chemostat Culturesx JF Microbiology, VO 136 IS 3 SP 395 OP 403 DO https://doi.org/10.1099/00221287-136-3-395 PB Microbiology Society, SN 1465-2080, AB The physiology of Saccharomyces cerevisiae CBS 8066 was studied in anaerobic glucose-limited chemostat cultures in a mineral medium supplemented with ergosterol and Tween 80. The organism had a μ max of 0·31 h−1 and a K s for glucose of 0·55 mm. At a dilution rate of 0·10 h−1, a maximal yield of 0·10 g biomass (g glucose)−1 was observed. The yield steadily declined with increasing dilution rates, so a maintenance coefficient for anaerobic growth could not be estimated At a dilution rate of 0·10 h−1, the yield of the S. cerevisiae strain H1022 was considerably higher than for CBS 8066, despite a similar cell composition. The major difference between the two yeast strains was that S. cerevisiae H1022 did not produce acetate, suggesting that the observed difference in cell yield may be ascribed to an uncoupling effect of acetic acid. The absence of acetate formation in H1022 correlated with a relatively high level of acetyl-CoA synthetase. The uncoupling effect of weak acids on anaerobic growth was confirmed in experiments in which a weak acid (acetate or propionate) was added to the medium feed. This resulted in a reduction in yield and an increase in specific ethanol production. Both yeasts required approximately 35 mg oleic acid (g biomass)−1 for optimal growth. Lower or higher concentrations of this fatty acid, supplied as Tween 80, resulted in uncoupling of dissimilatory and assimilatory processes., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-136-3-395