Covalent Immobilization of Candida antarctica Lipase B on Functionalized Hollow Mesoporous Silica Nanoparticles

Candida antarctica lipase B (CALB) produced by recombinant Pichia pastoris was covalently immobilized to a carboxyl-functionalized hollow mesoporous silica sphere (HMS) synthesized by sol-gel precipitation. The HMS was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffractometer (XRD), and Brunauer-Emmett-Teller (BET). The immobilized CALB was characterized through Fourier transform infrared spectra (FT-IR) and elemental analysis to verify the binding of enzyme. The free and immobilized CALB were tested in tributyrin hydrolysis. Results revealed that CALB loading capacity of HMS-COOH was about 28.6 mg/g support and the corresponding enzyme activity was up to about 2700 U/g support at optimal pH and temperature, which was 6.5 and 30 degrees C respectively. Moreover, compared with free CALB, the immobilized CALB presented more resistant towards the reaction pH and temperature changes. Furthermore, the immobilized CALB retained 60 % residual activity after eight batches of recycling and exhibited better thermal stability and storage stability, which was promising in the potential industrial applications.

Automated summary

CALB immobilized on carboxyl-functionalized hollow mesoporous silica spheres exhibited higher loading capacity and enzyme activity than free CALB. The immobilized CALB also showed better resistance to changes in reaction pH and temperature, as well as improved thermal and storage stability, making it promising for industrial applications.