Immobilization of laccase enzyme on zinc oxide and silver doped zinc oxide nanoparticle-chitosan-PVPP composite beads

Abstract

Laccase enzyme has gained popularity due to its wide range of substrates, use of only molecular oxygen as a co-factor and release of water as a by-product. In order to improve its reusability in harsh conditions, various supports have been explored for its immobilization. In this study, laccase was immobilized on zinc oxide-chitosan/polyvinylpolypyrolidone (ZnONPs/CS/PVPP) and silver doped zinc oxide-chitosan/polyvinylpolypyrolidone (Ag@ZnONPs/CS/PVPP) beads. The Ag@ZnONPs/CS/PVPP beads showed a higher immobilization yield and retained enzyme activity (76.0% and 50.0% respectively) compared to the ZnONPs/CS/PVPP beads (50.4% and 41.7% respectively). The biocatalysts demonstrated improved enzyme stability at higher temperatures and longer storage stability compared to the free enzyme hence show potential for further biotechnological applications.