It is known that running biochemical processes under optimal temperature control is more profitable than using isothermal conditions. To quantify this phenomenon, a biotransformation process with native enzyme deactivation independent of the substrate concentration occurring in a perfect batch reactor was analyzed. A general analytical expression was derived that can answer the question of how much enzyme can be saved by applying optimal temperature control instead of the commonly used isothermal conditions. The presence of both lower and upper temperature limitations were taken into account. From these equations, it is possible to obtain an all-dependences expression describing the amount of saved enzyme that may be present in biotransformations with the analyzed enzyme deactivation. The effect of the activation energy quotient on the magnitude of such benefits was also considered. It was proven that, lower catalyst activity, for relatively high values of the activation energy quotient causes significant enzyme savings by two times or even more when applying optimal temperature control rather than the isothermal process. Based on examples of sucrose hydrolysis by invertase and xylan hydrolysis by xylanase, the obtained results were verified.