Immobilization of -glucosidase by self-catalysis and compared to crosslinking with glutaraldehyde

Nanoparticles have been successfully used for immobilization of different enzymes. The enzyme immobilized by nanomaterials has promising application in the biotechnological industry. The beta-glucosidase is very important in industrial field. The immobilization of beta-glucosidase by nanomaterials increases its activity and reusability. In this work, the beta-glucosidase was extracted from fruiting bodies of Agrocybe aegirit and was purified by anion exchange. The beta-glucosidase was immobilized by SiO2 nanoparticles (nano-SiO2) crosslink with glutaraldehyde (GA). On the other hand, the beta-glucosidase firstly immobilized by process adsorption and then crosslink with genipin (GP) which was produced by the hydrolysis of geniposide by beta-glucosidase. Then we compared the properties of both immobilized GA-crosslinked beta-glucosidase and GP-crosslinked beta-glucosidase, their immobilization yields were 83.34% and 96.29% respectively. The GA-crosslinked beta-glucosidase and free beta-glucosidase revealed optimal pH at 6.0. The optimal pH of GP-crosslinked beta-glucosidase was ranging between 4.5 and 7.5. The GA-crosslinked beta-glucosidase and GP-crosslinked beta-glucosidase revealed the optimal temperature at 50 degrees C, 70 degrees C respectively. For the free beta-glucosidase, the optimal temperature was 55 degrees C. Furthermore, the GA-crosslinked beta-glucosidase and GP-crosslinked beta-glucosidase were characterized by scanning electron microscope (SEM). The geniposide consumption in the reaction system of GA-crosslinked beta-glucosidase was analyzed by high performance liquid chromatography (HPLC). (C) 2019 Elsevier B.V. All rights reserved.