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Acetaldehyde mediates growth stimulation of ethanol-stressed Saccharomyces cerevisiae: evidence of a redox-driven mechanism

Author:
Vriesekoop, Frank, Barber, Andrew R., Pamment, Neville B.
Source:
Biotechnology letters 2007 v.29 no.7 pp. 1099-1103
ISSN:
0141-5492
Subject:
Saccharomyces cerevisiae, acetaldehyde, biomass, ethanol, fermentation, glucose, glycolysis
Abstract:
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.
Agid:
2751067