Adsorption and catalytic activity of Porcine pancreatic lipase on rod-like SBA-15 mesoporous material

Rocklike SBA-15 mesoporous material was synthesized using amphiphilic Pluronic polymer surfactant P123 (EO20PO70EO20) as structure-directing agent. The sample was characterized by SEM, TEM, SAXRD, N-2 adsorption-desorption isotherms and FT-IR spectra. It had a high specific Surface area of 490 m(2) g(-1). a total pore volume of 1.04 cm(3) g(-1) and a pore diameter of 7.63 nm. The pore diameter was large enough for accommodating Porcine pancreatic lipase (PPL, 4.6 x 2.6 x 1.1 nm(3)) molecules inside the channels. The physical adsorption immobilization of PPL on the rod-like SBA-15 mesoporous material in buffer solutions was studied via a direct one-step immobilization method. The results obtained by SAXRD and N2 adsorption-desorption isotherms clearly showed that PPL was adsorbed into the channels of SBA-15 and the ordered mesoporous structure of SBA-15 after adsorption of PPL was retained. The catalytic activity, thermal stability, and reusability Of the immobilized PPL were measured in phosphate buffer solution by hydrolysis of triacetin. The immobilized PPL showed excellent adaptability at higher pH and better thermal stability comparing with free PPL. (C) 2009 Elsevier B.V. All rights reserved.