Activity and stability of lipase in Aerosol-OT/isooctane reverse micelles

The stability of Candida rugosa lipase, which catalyzes the hydrolysis reaction of olive oil in AOT/isooctane reverse micelles, decreased with the increase of omega(0) (defined as the molar ratio of water to surfactant) and Aerosol-OT concentration. The addition of a non-ionic cosurfactant, tetraethylene glycol dodecyl ether (C12E4), preserved enzymatic activity. The residual activity of the lipase was 53% after 24 h, while the enzyme completely lost its activity within 6 h in the absence of C12E4 addition. The stabilizing effect of C12E4 resulted in the increase of conversion. The enhancement of the activity and stability of lipase in reverse micelles by the addition of C12E4 may contribute to increase the rigidity of the micellar matrix stabilizing the enzyme structure.