Stability of a recombinant cutinase immobilized on zeolites

Thermal stabilities of a recombinant cutinase from Fusarium solani pisi, immobilized by adsorption/deposition on NaA and NaY zeolites, and on the reference supports polyamide Accurel-PA6 and alumina, were evaluated for long periods of time at different temperatures. The prepared samples were equilibrated in closed vessels with saturated salt solutions, in order to achieve a water level in the preparations correspondent to a water activity of approximate to0.97, which was the optimal value for the alcoholysis reaction of butyl acetate with hexanol in isooctane, and stored in the saturation vessels at 30, 40 and 50degreesC. The activity of the immobilized cutinase, for the alcoholysis transformation, was measured as a function of the storage period of time. A 24 h thermal treatment at 90, 120 and 150degreesC was also applied, over some immobilized preparations, in order to check the level and reversibility of the immobilized cutinase deactivation. (C) 2002 Elsevier Science Inc. All rights reserved.