Influence of protic ionic liquids in the immobilization of Thermomyces lanuginosus lipase by different methodologies

In this work was studied the improvement of immobilization of lipase from Thermomyces lanuginosus (LTL) by sol-gel method by adding protic ionic liquids (PILs) during immobilization, also was performed an overload to the immobilized lipases obtained by encapsulation through adsorption and covalent binding. Lipase encapsulation was studied  in the presence of alkyl chain length of protic ionic liquids (methylmonoethanolamine-based). The better value of total activity yield (Ya) was 99.6 % to system using 1.0 % (w/v) of hydrophobic PIL (C4). The immobilized obtained by covalent binding and adsorption have shown activity of 759 and 164 U/g, respectively.  The resulting hydrophobic matrices and immobilized lipases were structurally characterized with regard to specific surface area (the BET method), adsorption-desorption isotherms and size (dp), spectrometry Fourier Transform Infrared - FTIR and Thermogravimetric Analysis – TGA. The analyzes of adsorption and desorption of nitrogen and FTIR showed change in porous structure and surface area. The physico-chemical characterization confirmed the presence of enzymes immobilized derivatives obtained in this study by identifying the presence of amino groups. Immobilized lipases with and without PIL showed higher thermal resistance compared to the pure matrix, verified by the TGA curves. Immobilized enzyme obtained by covalent binding preserved more than 50 % of its activity after 16 cycles of operation. The results show that LI enhance the immobilization of enzymes and their application in biocatalysis, including biotransformation of oils to obtain fuels.