Acetaldehyde addition and pre-adaptation to the stressor together virtually eliminate the ethanol-induced lag phase in Saccharomyces cerevisiae

Aims: To show that the ethanol-induced lag phase in yeast can be almost eliminated by combining pre-adaptation with acetaldehyde supplementation. Methods and Results: Pre-adaptation to noninhibitory concentrations of ethanol and supplementation of unadapted cultures with acetaldehyde each separately reduced the lag phase of ethanol-inhibited cultures by c. 70%. By combining the two methods the ethanol-induced lag phase was virtually eliminated (90% reduction in lag time). Conclusions: Pre-adaptation to ethanol and acetaldehyde supplementation appear to promote yeast growth through different mechanisms, which are additive when combined. Significance and Impact of the Study: The combination of the above procedures is a potentially powerful tool for reducing the lag of stressed cultures, which may have practical applications: e.g. in reducing the lag of yeasts inoculated into lignocellulosic hydrolysates employed in fuel ethanol production.