INHIBITORY-ACTION OF PALMITIC ACID ON THE GROWTH OF SACCHAROMYCES-CEREVISIAE

High concentrations of long-chain fatty acids have been found to be ha rmful to mammalian cells and prokaryotic organisms. This effect was in vestigated in Saccharomyces cerevisiae. Addition of 3 mmol/L palmitate to a yeast extract - peptone medium caused a significant inhibition o f cell growth during the first 2 d of incubation, followed by renewed growth and palmitate utilization. Inhibition was also observed with pa lmitate concentrations down to 0.1 mmol/L. As inferred from catalase a ctivity determinations, this effect was found to correlate with the ab sence of peroxisome proliferation. Finally, no inhibition was observed in exponential-phase cultures or in the presence of 0.1 g/L glucose, this suggesting that the physiological state of the cell may determine whether its growth will be inhibited by fatty acids.