Improvement on laboratory fermentation equipment to study Saccharomyces cerevisiae metabolism

Beside being an ordinary fermenter, the present equipment was conceived to sample the medium, to store the samples and to record photographs of the yeasts. Ten sensors were used to measure gas exchanges. During the growth of ScM1 (a Saccharomyces cerevisiae strain) on glucose, we could observe two different linear decreases of CO₂ production rates (18.17±0.12 mmol CO₂ h^–2 (g biomass)^–1 and 8.67±0.12 mmol CO₂ h^–2 (g biomass)^–1), together with a sudden variation of slope during the respiro-fermentative phase. NomenclatureF_inInletairFlowlh^–1 F_outOutletgasFlowlh^–1 _inInletairtemperature°C_outOutletgastemperature°CP_atmAtmosphericPressuremmHgP_inInletairOverPressuremmHgP_outOutletgasOverPressuremmHgDODissolvedO₂ mg l^–1 pO₂PartialPressureO₂ in Outlet gas % (v/v) pCO₂PartialPressureCO₂ in Outlet gas % (v/v) Int(t) Whole number of hours