An important aspect of industrial enzymes is their stability during production, storage and their final application. The enzyme stability can be improve by the development of various stabilization strategies such as the use of additives, chemical modifications or immobilization, and protein engineering. An other way to improve their stability is to increase the actual knowledge about enzyme inactivation processes in order to control the parameters responsible for inactivation.

In this study, we focused on the latter, and more precisely we have identify the inducers of the inactivation and aggregation of lysozyme in a stirred-reactor. Mechanical stirring by a Rushton turbine strongly enhances irreversible lysozyme inactivation and aggregation. The inactivation constant, in a Holland and Chapman type reactor, is found proportional to the power imparted by the impeller that shows clearly the effect of stirring on lysozyme inactivation. Nevertheless, the respective kinetic constants obtained in other reactors are not proportional with the dimensionless Reynolds number (Re) used for the comparison of the hydrodynamic flow in the reactors.

Obviously stirring is not the only parameter responsible of enzyme inactivation. Other factors like surface and nature of solid-liquid interfaces seem to act on this process. In fact stirring strongly enhances lysozyme inactivation and aggregation but does not directly provoke it as we shown in this paper that specifies the role of the solid-liquid interfaces and molecular interfaces of inactivated lysozyme molecules as inducers of this process enhanced by mechanical stirring.