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

The stability of Candida rugosa lipase, which catalyzes the hydrolysis reac tion of olive oil in AOT/isooctane reverse micelles, decreased with the inc rease of omega(0) (defined as the molar ratio of water to surfactant) and A erosol-OT concentration. The addition of a non-ionic cosurfactant, tetraeth ylene glycol dodecyl ether (C12E4), preserved enzymatic activity. The resid ual 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 stabiliz ing effect of C12E4 resulted in the increase of conversion. The enhancement of the activity and stability of lipase in reverse micelles by the additio n of C12E4 may contribute to increase the rigidity of the micellar matrix s tabilizing the enzyme structure.