Improving adsorption and activation of the lipase immobilized in amino-functionalized ordered mesoporous SBA-15

Ordered mesoporous SBA-15 was prepared by hydrothermal process and was functionalized with (3-aminopropyl) triethoxysilane (APTES) by post-synthesis-grafting method. The materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive spectrometer (EDS), small-angle X-ray powder diffraction (SAXRD), N-2 adsorption-desorption and Fourier transform infrared spectroscopy (FT-IR). The results indicated that SBA-15 had a 2-dimensional hexagonal p6mm mesoscopic structure and the mesoscopic structure was remained after the functionalization procedure. The activities of porcine pancreatic lipase (PPL) immobilized in SBA-15 by physical adsorption and in APTES functionalized SBA-15 by chemical adsorption were studied by hydrolysis of triacetin. Chemically adsorbed PPL showed higher loading amount and catalytic activity comparing with physically adsorbed PPL. The stability of immobilized PPL against thermal and pH of reaction medium was significantly improved. Recycling experiments showed that chemically adsorbed PPL exhibited better reusability than physically adsorbed PPL (C) 2011 Elsevier Masson SAS. All rights reserved.