Deactivation of isoamylase and β-amylase in the agitated reactor under supercritical carbon dioxide.

The current research examines the impact of agitation on deactivation of isoamylase and β-amylase under supercritical carbon dioxide (SC-CO2). Our experimental results showed that the activity of either enzyme decreased with increasing pressure or speed of agitation. The degree of enzymatic deactivation caused by pressure became more prominent in the presence of agitation, suggesting that the agitation plays an important role in enzymatic deactivation in SC-CO2 environment. Moreover, the enzymatic deactivation behavior associated with agitation and pressure was further quantitatively analyzed using a proposed inactivation kinetic model. Our analysis indicated that isoamylase and β-amylase exhibited significantly different relationships between the inverse of percentage residual activity and the product of number of revolution per time and time elapsed under pressurized carbon dioxide. We believe that the outcome from this work may provide a better understanding of the effects of agitation and pressure in enzyme deactivation behavior under SC-CO2.