Ultradian oscillation of Saccharomyces cerevisiae during aerobic continuous culture: hydrogen sulphide mediates population synchrony

Saccharomyces cerevisiae showed an ultradian respiratory oscillation during aerobic continuous culture. Analysis of the off-gas revealed that hydrogen sulphide production also oscillated. Production was first detected at the onset of low respiration and reached a maximum (1.5 mu M) prior to minimum respiratory activity. Then H2S concentration fell rapidly to below 0.2 mu M before the onset of high respiration. Injection of respiratory oscillation perturbation agents, such as glutathione (50 mu M), NaNO2 (50 mu M) or ace taldehyde (4.5 mM), transiently increased H2S production above 6 mu M, The synchronization properties of H2S were analysed to reveal that changes of o scillation period and amplitude were dependent on H2S concentration in cult ure. It is concluded that H2S produced during oscillation produces populati on synchrony by respiratory chain inhibition. Copyright (C) 2000 John Wiley & Sons, Ltd.