Glucose respiration and fermentation in Zygosaccharomyces bailiiand Saccharomyces cerevisiaeexpress different sensitivity patterns to ethanol and acetic acid

In the yeast Zygosaccharomyces bailii ISA 1307, respiration and fermentation ofglucose were exponentially inhibited by ethanol, both processes displaying similar sensitivity tothe alcohol. Moreover, the degree of inhibition on fermentation was of the same magnitude as thatreported for Saccharomyces cerevisiae. Acetic acid also inhibited these two metabolicprocesses in Z. bailii, with the kinetics of inhibition again being exponential. However,inhibition of fermentation was much less pronounced than in S. cerevisiae. The valuesestimated with Z. bailii for the minimum inhibitory concentration of acetic acid rangedfrom 100 to 240 mmol l−1total acetic acid compared with values of near zeroreported for S. cerevisiae. The inhibitory effects of acetic acid on Z. bailii were notsignificantly potentiated by ethanol.