Acetaldehyde mediates growth stimulation of ethanol-stressed Saccharomyces cerevisiae: evidence of a redox-driven mechanism.
The ability of acetaldehyde (90 mg l(-1)) to stimulate ethanol-stressed S. cerevisiae fermentations is examined and reasons for the effect explored. Alternative metabolic electron acceptors generated similar stimulatory effects to acetaldehyde, decreasing the ethanol-induced growth lag phase from 9 h to 3 h, suggesting a redox-driven effect. The exposure to ethanol caused an instant 60% decline in intracellular NAD(+) which was largely prevented by the addition of acetaldehyde. Furthermore, the exposure to ethanol affected glycolysis by decreasing the rate of glucose utilisation from 0.33 g glucose g(-1) biomass h(-1) to 0.11 g glucose g(-1) biomass h(-1), while the addition of acetaldehyde to an ethanol stressed culture increased this rate to 0.14 g glucose g(-1) biomass h(-1).
Vriesekoop
Frank
F
Institute for Food and Crop Science, School of Science and Engineering, University of Ballarat, Ballarat, VIC, Australia. f.vriesekoop@ballarat.edu.au
Barber
Andrew R
AR
Pamment
Neville B
NB
D000079:Acetaldehyde / Q000494:pharmacology*; D000447:Aldehydes / Q000494:pharmacology; D004583:Electrons; D000431:Ethanol / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000254:growth & development*; D013997:Time Factors
D000447:Aldehydes; D009243:NAD; D000431:Ethanol; C005556:propionaldehyde; D000079:Acetaldehyde; D005947:Glucose