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Fusarium solani pisi recombinant cutinase was immobilized on sodium form of zeolite Y (NaY) and polyamide Accurel PA6 and used to catalyze the alcoholysis reaction of butyl acetate with hexanol, in isooctane. The influence of some of the relevant parameters to the enzyme alcoholysis activity, such as temperature, buffer molarity and pH of the enzyme solution, hexanol and butyl acetate concentrations, were studied by means of a factorial design plan. By knowing the system response to the experimental design, the effects of each factor and its interactions were determined. In the case of the preparations with NaY zeolite, the main effects are due to temperature and buffer molarity, while pH and hexanol concentration have little effect on activity. In case of the cutinase adsorbed on Accurel PA6 the main effects are due to temperature, buffer molarity and pH of the enzyme solution.

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.

A recombinant cutinase from Fusarium solani pisi was immobilized by adsorption/deposition onto several zeolites. These preparations were used to catalyse the alcoholysis of butyl acetate with hexanol in isooctane. Ground state diffuse reflectance measurements were performed for the preparations previously equilibrated with salt solutions at well-defined optimum water activity. The corresponding cutinase fluorescence emission spectra were used to detect different conformational enzyme states, induced by different zeolite properties. Significant conformational changes were observed, with important consequences on the enzymatic activities.

Fusarium solani pisi recombinant cutinase was immobilized by adsorption on NaY zeolite. The kinetics of the alcoholysis reaction of butyl acetate with hexanol in isooctane catalyzed by cutinase immobilized on NaY zeolite, was studied. The reaction kinetics is suggested to follow a Ping-Pong bi–bi mechanism in which competitive inhibition by excess of alcohols has been identified. No evidence of any significant external diffusional limitation has been detected. The time validation of the model was successfully achieved simultaneously for 15 experimental product evolutions in a batch stirred tank reactor (BSTR) for different initial reactant concentrations.

The ground-state and transient absorption, prompt and delayed fluorescence of tetraphenylporphyrin (TPP) adsorbed onto the external surface of different zeolites was monitored using diffuse-reflectance steady-state and laser flash photolysis. The delayed fluorescence (DF) of TPP detected in the presence of O 2 is attributed to the energy transfer from 3 TPP to 3 O 2 to form 1 O 2 and subsequent energy transfer from 1 O 2 to some other 3 TPP within the organised molecular ensembles on the zeolite surface. The spectroscopic and kinetic parameters, namely the yield of DF (2–20% relative to prompt fluorescence), depend on the zeolite properties: the observed differences were correlated with the acid-base properties of the two zeolite series studied in this work (KA, NaA, CaA) and (NaA, NaX, NaY).

A recombinant cutinase from Fusarium solani pisi was immobilized by adsorption on several zeolites and its activity towards the alcoholysis reaction of butyl acetate with hexanol, in organic media (isooctane), was measured as a function of the water content and water activity. The effects of the zeolite framework composition (including cation nature) and acidity were studied. The results were compared with other commonly used supports: polyamide Accurel-PA6, silica and alumina. Both the nature of the cation and the silica:alumina (Si:Al) ratio of the framework revealed to be important parameters. The most promising results were obtained for supports with little acidity and with lower Si:Al ratio. This last observation is in accordance with the results obtained with silica and alumina.

Acidic samples of Y zeolite were prepared by ion exchange promoted using microwave irradiation. Interesting exchange levels were obtained with only a few minutes of irradiation. The catalytic properties of these samples were evaluated using the transformation of iso‐octane; the observed conversions lie in the same range as those for the samples prepared by the conventional ion‐exchange method of stirring the mixture of the sodium form with an ammonium salt solution for several hours; the deactivation with time‐on‐stream was significantly reduced for the catalysts prepared by the irradiation method in the cases of highest activity.