SELECTION OF HYDROPHOBIC MEMBRANES IN THE LIPASE-CATALYZED HYDROLYSISOF OLIVE OIL

A hydrophobic membrane (HVHP, polyvinylidene difluoride) was selected out of HVHP, PTHK and PTGC (polysulfone) membranes to immobilize Candi da rugosa lipase by physical adsorption in the hydrolysis of olive oil in a stirred diffusion cell. A previous model that assumed the Michae lis-Menten kinetics and Langmuir adsorption isotherm for the adsorbed lipase was used to interpret the variation of initial hydrolysis rates with enzyme and substrate concentrations. Replacing the aqueous phase by a fresh buffer, with or without containing partially deactivated l ipases, during the reaction did not affect the enzyme activity for the adsorbed lipase. Moreover, the same enzyme performance was obtained w hen a fresh and a regenerated membrane was used as the carrier in the membrane reactor. (C) 1998 Elsevier Science B.V. All rights reserved.