CARBON AND ENERGY UNCOUPLING ASSOCIATED WITH CELL-CYCLE ARREST OF CDCMUTANTS OF SACCHAROMYCES-CEREVISIAE MAY BE LINKED TO GLUCOSE-INDUCED CATABOLITE REPRESSION

Several cell division cycle (cdc) mutants of Saccharomyces cerevisiae (cdc28, cdc35, cdc19, cdc21, and cdc17) at the restrictive temperature (37 degrees C) in the presence of 1% glucose and defined medium diver t most of the carbon (similar to 50%) to ethanol production with low b iomass growth yields (Y-glc) that correlate with carbon and energy unc oupling and arrest of cell proliferation, The cdc mutants studied are shown to be glucose-repressed, while this was not the case for the wil d-type A364A (WT), At 37 degrees C, in the presence of 1% glycerol, de repressed cdc28 mutant cells did not show arrest of cell division and carbon and energy uncoupling since the Y-glc levels measured were simi lar to those of the WT strain, These results suggest that the increase d fermentative ability and carbon and energy uncoupling exhibited in t he presence of glucose by cdc mutants with respect to those exhibited by the WT may be due to catabolite repression. (C) 1995 Academic Press , Inc.