Involvement of oxidative stress in the regulation of H2S production during ultradian metabolic oscillation of Saccharomyces cerevisiae

Periodic evolution of H2S during aerobic chemostat culture of Saccharomyces cerevisiae resulted in ultradian metabolic oscillation via periodic inhibition of respiratory activity. To understand the nature of periodic H2S evolution, we investigated whether oxidative stress is associated with H2S production. The cellular oxidative states represented by intracellular level of lipid peroxides oscillated out of phase with the oscillation of dissolved O2. Pulse addition of antioxidant, oxidative agent or inhibitor of antioxidation enzymes perturbed metabolic oscillation producing changes in H2S evolution. Analysis of H2S production profiles during perturbation of oscillation revealed that the amount of H2S production is closely linked with cellular oxidative states. Based on these results and our previous reports, we suggest that oxidative stresses result in periodic depletion of glutathione and cysteine, which in turn causes stimulation of the sulfate assimilation pathway and H2S production.