Printed in Great Britain. @ 1993 IUPAC Calorimetry of technical microbial reactions

Abstract- Heat generation is a very conspicuous phenomenon in large scale bioreactors and could in principle quite easily be measured by the temperature increase of the cooling water. Taking yeast cultures growing on a mixed oxido-reductive metabolism for various reasons as an example, this paper demonstrates how heat dissipation measurements may be used in combination with one other on-line measurement in order to obtain a quantitative estimation of the nature of the on-going metabolism and of the current overall stoichiometry. The application of such measurements to controlling fed-batch cultures is also discussed