Preparation of Immobilized Lipase through Combination of Cross-Linked En-zyme Aggregates and Biomimetic Silicification

Abstract

The hybrid biocatalyst was prepared by the combination of cross-linked enzyme aggregates (CLEAs) and biomimetic silicification, where the lipase Candida sp. 99-125 was used as model enzyme. The preparation conditions of lipase-CLEAs were optimized and the resulting activity of 771 U/g was obtained. Under the optimum conditions, 75% of the activity recovery was obtained. P/CLEAs was prepared by coprecipitation of lipase with polyethylene-imine (PEI), and the resulting activity was 897 U/g. The activity recovery of P/CLEAs was about 88%. The silica coating was formed on the outside surface of P/CLEAs via the induction of PEI. The resulting Coated-CLEAs showed high reusability. The stability of the Coated-CLEAs, including the resistance to trypsin and organic solvents, was also significantly improved.