Effects of elevated temperature on growth, respiratory-deficient mutation, respiratory activity, and ethanol production in yeast.
Some mesophilic yeasts and a thermotolerant strain of Saccharomyces cerevisiae were found to grow at 40 degrees C in complex media containing 1% yeast extract when an inoculum of 10(6) or more cells.mL-1 was used. Yeast extract (6%) permitted Saccharomyces cerevisiae to grow at 40 degrees C even with a smaller inoculum size (10(5) cells.mL-1). The fraction of respiratory-deficient (petite) mutants in 40 degrees C grown culture was less than 10% except for the thermotolerant strain, which showed greatly increased levels depending on culture conditions. Seven of eight yeast strains exhibited extremely reduced cytochrome oxidase activity when grown at 40 degrees C irrespective of the frequency of the petite mutation. In contrast, the accumulation of ethanol in the medium and the ethanol-producing activity of the cells were not affected by growth at 40 degrees C.
Yamamura
M
M
Department of Industrial Chemistry, Faculty of Engineering, Kyoto University, Japan.
Nagami
Y
Y
Vongsuvanlert
V
V
Kumnuanta
J
J
Kamihara
T
T
D003470:Culture Media; D003576:Electron Transport Complex IV / Q000378:metabolism; D000431:Ethanol / Q000096:biosynthesis*; D006358:Hot Temperature; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism
D003470:Culture Media; D000431:Ethanol; D003576:Electron Transport Complex IV