Investigation of growth and metabolism of Saccharomyces cerevisiae (baker's yeast) using microcalorimetry and bioluminometry

Abstract

The heat evolution of aerated and non-aerated batch cultures of Saccharomyces cerevisiae (baker's yeast) in complex glucose medium was investigated by flow microcalorimetry. The course of heat output, substrate consumption and intracellular ATP concentration were extensively studied during the occurrence of an unexpected late peak. The results showed that the acetate could not be responsible for the occurrence of the late peak after the cessation of the growth. Enzyme induction and storage carbohydrate mobilization could be associated with this phenomenon. Linear relationships existed between initial glucose concentration, biomass concentration and total heat output and also between the log of viable cell numbers and the log of integrated heat output. A logistic equation was derived that fit the heat output curves. A model is proposed for predicting the biomass concentration from the power-time curves during the anaerobic growth of S. cerevisiae.