Enzyme deactivation activity profile

Berberich et al. used salt hydrate pairs to control water activity in [BMIM][PF6]. The results were in good agreement with that obtained for water activity control using saturated salt solutions. The advantage of pre-equilibration is that the contact of the enzyme with the used salt and thus enzyme deactivation can be avoided. On the other hand it is only applicable for initial rate measurements. This disadvantage can be overcome by controlling water activity with salt hydrate pairs. Berberich et al. measured initial rate - water activities for the transesterification reaction of methyl methacrylate with 2-ethylhexanol in either hexane or [BMIM][PF6]. Both reaction systems gave similar profiles [72],... 

For the optimal strategy of maintaining operational stability, Lee et al. have calculated the optimal profile of addition of fresh, non-deactivated enzyme into a CSTR under different deactivation kinetics. If a CSTR is charged initially with an amount of enzyme of initial activity N0, at time t under deactivation, the amount remaining is given by Eq. (5.83), where k(t) denotes an arbitrary deactivation function (J. Y. Lee, 1990). 

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