Control of enzyme activity in stirred bioreactors

In this work the problem of determining the feed rate policy of fresh enzyme into stirred bioreactors to offset the loss of activity due to enzyme deactivation is addressed. On the basis of a series-type deactivation mechanism with arbitrary deactivation kinetics, it is shown that the feed rate policy is a feedback function of the deactivation rate. From both the theoretical and the practical viewpoints, these results provide a useful tool in understanding enzyme deactivation, and in designing bioreactor operation.