ABSTRACT
In theory, the heat production rate is a perfect measure for controlling and analyzing bioprocesses due to the following reasons. Any bioconversion is accompanied by either generated (exothermic) or consumed (endothermic) heat. Measuring this heat signal will, thus, yield vast information about the process. The law of Hess connects the heat tightly with the stoichiometry of the bioprocess. Additionally, the heat production rate is also correlated with the kinetics of the process. Furthermore, the combination of heat measurements with respirometry is theoretically suited to quantify the coupling between catabolic and anabolic reactions. Another advantage is that the information about the system is provided in real time. Beside these reasons, heat measurements also have a lot of practical advantages. Unlike most other biochemical sensors, thermal transducers can be mounted in a protected way that prevents fouling thereby minimizing response drift. Calorimetry works in optically opaque solutions and does not need any labeling of cells. Finally, it can be applied on different scales from few nL up to cubic meters (m3) [1].
