A simple process of biotransformation carried out in a batch reactor in the presence of native enzyme undergoing deactivation independent of substrate concentration has been analyzed. An analytical expression has been derived enabling answering the question how much of enzyme can be saved if instead of commonly applied isothermal conditions an optimal temperature control without its limitations were used. An effect of the quotient of the activation energy on the magnitude of such benefits has also been considered. It has also been proved that the reaction kinetics has no influence on the derived expression. Based on an example of sucrose hydrolysis by immobilized invertase the obtained result has been verified. (C) 2012 Elsevier Ltd. All rights reserved.