High catalytic performances of Pseudomonas fluorescens lipase adsorbed on a new type of cyclodextrin-based nanosponges

Abstract

Lipases are water-soluble enzymes that catalyze the hydrolysis of triacylglycerols (in aqueous media) or trans-esterification reactions (in microaqueous media) and are involved in a number of industrial applications. As a limit to lipase application is represented by the need for interfacial activation, the search for suitable solid supports able to fulfill this requirement is always ongoing. In the present work, we report the preliminary characterization of a system obtained by adsorbing Pseudomonas fluorescens lipase on a newly synthesized cyclodextrin-based carbonate nanosponge (CD–NS–1:4). The activity and structural stability of lipase adsorbed on this new support were evaluated by checking the effect of temperature, pH changes and organic solvents (methanol) on the enzyme structure and function, which were compared with those of the free enzyme in solution. Our data show that the non-covalent interaction of Ps. fluorescens lipase with CD–NS–1:4 results in enzyme structural and functional stabilization, as it was still active after 66 days of incubation at T ∼ 18 °C. Stabilization with respect to T, pH and the presence of organic solvent was observed as well as, unlike the solubilized enzyme, the adsorbed lipase was active at T > 40 °C, at pH 5 and after 24-h incubation with 70% (v/v) methanol (13% residual activity).