Immobilization of thermophilic lipase in inorganic hybrid nanoflower through biomimetic mineralization

Thermophilic lipase QLM from Alcaligenes sp. was successfully immobilized in Cu3(PO4)2-based inorganic hybrid nanoflower through biomimetic mineralization. The morphology, structure and element composition of immobilized enzyme were systemically characterized to elucidate the successful loading of enzyme molecules. The optimal temperature (65 °C) and pH (8.0) of immobilized enzyme were then determined by monitoring the hydrolysis of p-nitrophenyl caprylate. Moreover, compared with free enzyme, immobilized enzyme in inorganic hybrid nanoflower exhibited enhanced stability against thermal, pH and metal ions, attributing to the protective effect of nanoflower shell. Additionally, the immobilized enzyme possessed excellent reusability and long-term storage stability, with slightly decreased activity after being repeatedly used for 8 cycles or stored in water at room temperature for 4 weeks. Overall, the immobilization in inorganic hybrid nanoflower provided a facile and effective approach for the preparation of immobilized enzymes with favorable activity, stability and reusability, and thus the strategy showed great potential in developing ideal catalysts for future biocatalytic applications.