Improvement on laboratory fermentation equipment to study Saccharomyces cerevisiae metabolism

Abstract

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. Nomenclature

F_in InletairFlowl h ⁻¹ F_out OutletgasFlowl h ⁻¹ θ_in Inletairtemperature°Cθ_out Outletgastemperature°CP _atm AtmosphericPressuremmHgΔP _in InletairOverPressuremmHgΔP _out OutletgasOverPressuremmHgDODissolvedO ₂ mg l⁻¹ pO₂ PartialPressureO ₂ in Outlet gas % (v/v) pCO₂ PartialPressureCO ₂ in Outlet gas % (v/v) Int(t) Whole number of hours