Immobilization of β-glucosidase on bifunctional periodic mesoporous organosilicas.

The aminopropyl-functionalized ethane-bridged bifunctional periodic mesoporous organosilicas (APEPMOs) were synthesized by the co-condensation of 1,2-bis (triethoxysilyl) ethane and 3-aminopropyltriethoxysilane in the presence of cationic surfactants octadecyltrimethylammonium chloride in basic medium. The pores of the APEPMOs were expanded with N,N-dimethyldecylamine and the pore-expanded materials were utilized as supports for β-glucosidase immobilization. A high enzyme loading of 120 mg per g support was achieved in 18 h, and 95.5 % of enzymatic activity was retained. β-Glucosidases were strongly immobilized on APEPMOs with only 5 % desorption in the washing step with buffer solution. The immobilized enzyme had 75 % activity after 20 batch reactions and had improved thermal stability, relative to the free enzyme. These results demonstrate that APEPMOs would be promising supports for β-glucosidases immobilization.