POLYAMINE METABOLISM IN SACCHAROMYCES-CEREVISIAE EXPOSED TO ETHANOL

Growth of the yeast Saccharomyces cerevisiae was unaffected by up to 2 4 h exposure to ethanol concentrations ranging from 1% to 9%, but was reduced following exposure to 12% ethanol. Concentrations of the polya mines putrescine, cadaverine and spermidine were not affected by a 24 h exposure to 12% ethanol, although there was a significant increase i n spermine level. These changes were accompanied by significant increa ses in the activities of the polyamine biosynthetic enzymes ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (AdoMetDC) and in the flux of label from ornithine into the polyamines. Formation of the cadaverine derivatives aminopropylcadaverine and N,N-bis(3-ami nopropyl)cadaverine was greatly increased in yeast exposed to 12% etha nol for 24 h, probably via the action of ODC, AdoMetDC and the aminopr opyltransferases. Exposure to 12% ethanol also led to substantial redu ctions in the uptake of putrescine and spermidine and the amino acid m ethionine.