Microcalorimetric investigations of the metabolism of yeasts VII. Flow-calorimetry of aerobic batch cultures

Abstract

The heat evolution of aerobic batch cultures of growing yeast (Saccharomyces cerevisiae) in glucose media was investigated by a combination of a flow-microcalorimeter with a fermentor vessel. The course of heat production, cell production and the rate of oxygen consumption were qualitatively the same for all glucose concentrations between 10 mM and 100 mM. Under optimal aerobic conditions a triphasic growth was observed due to the fermentation of glucose to ethanol, respiration of ethanol to CO₂ and acetate, and respiration of acetate to C0₂. Energy and carbon were found to be in balance for all glucose concentrations.