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 ≈0.97, 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 50 °C. 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 150 °C was also applied, over some immobilized preparations, in order to check the level and reversibility of the immobilized cutinase deactivation.