Optimization of inulin hydrolysis by inulinase accounting for enzyme time- and temperature-dependent deactivation

In the present work a deactivation model for an inulinase from Aspergillus niger is presented; a first order kinetic is found and the deactivation constant kd is related to temperature through the Arrhenius model. The deactivation model was satisfactorily validated and implemented into a kinetic model for inulin hydrolysis predictions; the result is a complete model that is able to predict reaction performances for substrate concentrations ranging between 10 and 40 g/l and reaction temperature up to 60 ◦ C, even on a long time scale. The model is also shown to be a powerful tool to understand reaction paths and to choose the optimal reaction conditions for long time scale processes. A relevant problem for enzymatic process temperature optimization is formulated and solved by means of the predictive model determined.