The hydroxyapatite nanowires as high loading carrier for immobilization of dextranase by crosslinking method

In this work, dextranase was immobilized on the surface of hydroxyapatite nanowires (HAPNWs) through covalent cross-linking method. The prepared HAPNWs-NH 2 -dextranase was characterized by FE-SEM, XRD, TGA and FT-IR spectroscopy. The results show that the dextranase was successfully immobilized on HAPNWs by covalent cross-linking method. The properties of HAPNWs-NH 2 -dextranase were studied and compared with free dextranase, such as catalytic activity, kinetic constants, thermal stability and pH stability. The loading capacity, storage stability and reusability of the immobilized enzymes were investigated. HAPNWs-NH 2 -dextranase demonstrated better enzyme activity at higher temperatures (92.28% vs 33.08% at 70 °C) and higher pH stability (93.17% vs 57.78% at pH 7.0) than free dextranase. The loading capacity of dextranase on HAPNWs-NH 2 -dextranase can reach up to 868.2 mg g −1 . HAPNWs-NH 2 -dextranase retained 83.38% of its initial activity after 12 cycles, indicating that the HAPNWs-NH 2 -dextranase could have great performance in industry fields.