The role of acetaldehyde and glycerol in the adaptation to ethanol stress of Saccharomyces cerevisiae and other yeasts.
Ethanol inhibition is a commonly encountered stress condition during typical yeast fermentations and often results in reduced fermentation rates and production yields. While past studies have shown that acetaldehyde addition has a significant ameliorating effect on the growth of ethanol-stressed Saccharomyces cerevisiae, this study investigated the potential ameliorating effect of acetaldehyde on a wide range of ethanol-stressed yeasts. Acetaldehyde does not appear to be a universal ameliorating agent for yeasts exposed to ethanol stress. It is also shown that as a result of an ethanol stress, most yeasts rapidly produce glycerol as an alternative means of NAD(+) regeneration rather than having a specific requirement for glycerol. The results strongly suggest that both ethanol and acetaldehyde exposure have a direct effect on the cellular NAD(+)/NADH ratio, which can manifest itself as modulations in glycerol production.
Institute for Food and Crop Science, School of Science and Engineering, University of Ballarat, Ballarat, Victoria, Australia.
Frank
F
Vriesekoop
Cornelia
C
Haass
Neville B
NB
Pamment
D000079:Acetaldehyde / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism*; D005990:Glycerol / Q000378:metabolism*; D009243:NAD / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000378:metabolism / Q000502:physiology; D013312:Stress, Physiological; D015003:Yeasts / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*
D009243:NAD; D000431:Ethanol; D000079:Acetaldehyde; D005990:Glycerol