The effect of ethanol on the growth of wild-type and pdc1 mutant Saccharomyces cerevisiae

Abstract

Saccharomyces cerevisiae produces energy by alcohol fermentation, as well as oxidative phosphorylation. An important component of fermentation is ethanol as a product of pyruvate metabolism and a reactant for energy production. We investigated the effects that the addition of ethanol has on the growth rates of wild-type and pdc1 mutant S. cerevisiae. Three concentrations of ethanol were added to wild-type and mutant yeast media: 0, 2.5 and 5 g/L. The media were kept at 30^oC and cell concentrations were determined every 1.5 hours for 6 hours. Analysis of our results, by two-way ANOVA testing, suggests that the pdc1 mutation has a negative effect on the growth rate, ethanol does not have an effect on growth rate, and ethanol does not have different effects on the growth rates of wild type and pdc1 mutant S. cerevisiae. Our results also suggest that our experiment ended during log phase. Trends suggest that if we had continued our experiment past the six-hour time, we may have seen a significantly negative effect of ethanol on growth rates of pdc1 mutant but not wild-type S. cerevisiae.