Increase in the enzymatic hydrolysis rate of triacetin using polyethylene particles packed in a column reactor

In this study, the hydrolysis of triacetin by Candida cylindracea Lipase wa s investigated in a recirculating column reactor containing polyethylene pa rticles. Lipase is known to show a high activity at the oil-water interface , but its activity in a homogeneous phase such as in the soluble triacetin- water system is very low. For this reason, non-porous polyethylene particle s were used as an adsorbent packing material in a column reactor to create an interface for soluble concentrations of triacetin. Triacetin is adsorbed from the aqueous solution on the surface of the polyethylene particles and then hydrolyzed by lipase. The variation in the hydrolysis reaction rates with triacetin concentration in both water soluble and insoluble regions wa s investigated. This was done with and without polyethylene particles that were 128 mu m, 200 mu m and 378 mu m in size. The comparison of the results shows that the inert polyethylene particles provide an increase of between 88-431% in the hydrolysis rate of triacetin for the different soluble conc entrations. Another important result obtained in this study was that all ap parent Michaelis constants for the cases with particles were smaller than t hat of a reference state without particles. (C) 1998 Elsevier Science S.A.