Enzyme Immobilization in Polymerized Ionic Liquids-based Hydrogels for Active and Reusable Biocatalysts

Abstract

Enzyme immobilization in polymerized ionic liquids (PILs) promises to be a versatile tool for simple recovery and reuse of catalysts. In this study, a raw extract of CalB was encapsulated in poly(VEImBr) and assessed with respect to solvent, temperature, amount of enzyme, leaching behavior, and reusability on the example of the kinetic resolution of rac-1-phenylethanol with vinyl acetate. This immobilization method increased the enzyme activity of the CalB raw extract in comparison to the non-immobilized enzyme. The desired product was synthesized with high enantiomeric excess (ee) and no leaching of active enzyme was observed in the experiments. The immobilization method was compared to Novozyme 435 and Lipozyme RM IM, as commercially available immobilisates. Nonpolar solvents, including n-heptane and n-dodecane, proved to be the best reaction solvents, showing nearly full conversion and high catalytic activities. The encapsulated ­lipase was easily recovered from the reaction mixture and reused for ten cycles.