Immobilized-enzyme activity under isothermal and non-isothermal conditions: Studies on beta-galactosidase as a model enzyme

The behaviour of catalytic reactions was studied when an enzyme is immobilized to a membrane interposed between two solutions of identical substrate concentration, kept at different temperatures. beta-Galactosidase was studied as a model enzyme. In the presence of a temperature gradient the apparent enzyme activity is higher than in comparable isothermal conditions. The activity increase is proportional to the applied transmembrane temperature difference. Two possible explanations are proposed for this behaviour. Various biotechnological applications are suggested.