Oscillatory metabolism ofSaccharomyces cerevisiaein continuous culture

Abstract

Short‐period (40–50 min) synchronized metabolic oscillation was found in a continuous culture of yeast Saccharomyces cerevisiae under aerobic conditions at low‐dilution rates. During oscillation, many parameters changed cyclically, such as dissolved oxygen concentration, respiration rate, ethanol and acetate concentrations in the culture, glycogen, ATP, NADH, pyruvate and acetate concentrations in the cells. These changes were considered to be associated with glycogen metabolism. When glycogen was degraded, the respiro‐fermentative phase was observed, in which ethanol was produced and the respiration rate decreased. In this phase, the levels of intracellular pyruvate and acetate became minimum, ATP became high and intracellular pH at its lowest level. When glycogen metabolism changed from degradation to accumulation, the respiratory phase started, during which ethanol was re‐assimilated from the culture and the respiration rate increased. Intracellular pyruvate and acetate became maximum, ATP decreased and the intracellular pH appeared high. These findings may indicate new aspects of the control mechanism of glycogen metabolism and how respiration and ethanol fermentation are regulated together under aerobic conditions.

Regulation of yeast oscillatory dynamics

“…Previously we have shown that many metabolites oscillate with a phase relationship to respiration (5,7,12). We expanded these data by using GC-MS to show that this oscillation is metabolome-wide (Fig.…”

“…The metabolite data set used previous work (5,7,12,21,22,25,27,28,37,38), and GC-MS analyses (SI Methods) of intracellular metabolites were used to construct the metabolite data set. All Western blots were carried out according to the manufacturer's instructions (Atto, Bunkyo-ku, Tokyo, Japan).…”

“…5] for months (4)(5)(6). These dynamics result in the temporal separation of many essential cellular functions, including redox biochemistry (7,8), transcription (9,10), energetics (11), chromosome cycle (1), and mitochondrial function (5). Although respiration is always active, the cellular redox state cycles between an oxidative phase and reductive phase.…”

Ultradian oscillators of the circadian clock in <i>Saccharomyces</i> <i>cerevisiae</i>

“…The latter underscores the vital role of water associated with the ENOX1 proteinbound copper hexahydrate in the oscillatory process [31]. Among the first defined clock-related oscillation in yeast, known as the respiratory oscillation, was a 40 min cycle of dissolved oxygen levels in continuous culture [20][21][22][32][33][34][35]. After establishing that the oscillations were driven by some aspect of ethanol metabolism [33], acetaldehyde and sulfide were found to be responsible for synchronizing the cell population in continuous culture [22].…”

Stress induces depletion of Cdc25p and decreases the cAMP producing capability in Saccharomyces cerevisiae

“…The strong feedback loop provides a good device for large amplitude fluctuations. Variations in cAMP level are known to occur upon glucose addition (Thevelein & Beullens, 1985), and have been reported during metabolic oscillations of cellular populations (Satroutdinov et al, 1992;Muller et al 2003). Oscillations in cAMP production might also be involved in the oscillatory shuttling of Msn2p in and out the nucleus (Jacquet et al, 2003).…”