Calorimetric study of the endogenous metabolism of yeast.

Abstract

A considerable amount of heat was produced when a suspension of yeast was added to a suspending medium in the absence of an exogenous energy source. The amount of heat produced was proportional to the cell concentration and accompanied by oxygen consumption, suggesting that the exothermic reaction may be due to the endogenous metabolism of cells. The patterns of heat production varied with the physiological state of cells, which were influenced by several factors including culture conditions, methods of storage, starvation, temperature and the suspending medium used for calorimetric measurements.