Oscillatory CO₂ evolution in glycolysing yeast extracts

Abstract

The rate of formation of carbon dioxide in cytoplasmic yeast extracts in an open system with continuous infusion of glucose was measured by membrane inlet mass spectrometry during glycolytic oscillations. The rate of CO2 production rose in the first third of each cycle to a maximum of about 100 mumol per ml yeast extract per hour and subsequently diminished to a final level of about 50 mumol per h. Measurements of the NADH light absorption under the same conditions revealed oscillations of relaxation type. The phase of high CO2 production could be related to the phase of the high NADH level, giving evidence that the flux in glycolysis is increased during the phase of high NADH concentration. Only half of the amount of injected glucose was metabolized to CO2 during the sustained oscillation, although free glucose did not accumulate.

Sustained glycolytic oscillations – no need for cyanide

“…The only compound secreted by yeast in which we detected oscillations, was CO 2 measured at m/z 44. MIMS has previously been used to detect oscillations in the CO 2 transient in glycolysing cell free yeast extracts [13] but it has never been used in a whole cell yeast suspension. In Fig.…”

Synchronization affector of autonomous short-period-sustained oscillation of Saccharomyces cerevisiae

“…However, in short-period oscillation, the trehalose level does not change and has no influence on the regulation of the oscillation. The period of glycolytic oscillation varies from less than l min (Aon et al, 1992) to 30 min (Das et al, 1990). This oscillation was found under anaerobic conditions, in contrast to the aerobic conditions of the autonomous short-period-sustained oscillation.…”

Free intracellular amino acid pools during autonomous oscillations in Saccharomyces cerevisiae

“…After induction by addition of glucose to starved cells under anaerobic conditions, oscillatory changes of primarily NAD(P)H, but also other variables with a period in the range of less than 1 min to 30 min, were stable for several minutes to hours. In the literature, different reasonable synchronization mediators such as ethanol or acetaldehyde are considered to transduce signals between cells, thereby stabilizing oscillations (Ghosh and Chance, 1964;Aldridge and Pye, 1976;Das et al;Aon et al, 1992;Richard et al, 1996;Wolf et al, 2000).…”