Immobilization of enzyme penicillin G acylase on functionalized nanoporous silicas for biocatalysis applications

Abstract

Various organically functionalized nanoporous SBA-15 materials were synthesized and characterized for the application of immobilization of enzyme penicillin G acylase (PGA) (E.C.3.5.1.11.4). The functionalized SBA-15 materials have pore sizes ranging from 60 a?? 90 ?? with two-dimensional (2D) pore arrays. The functional groups were incorporated by co-condensation of tetraethyl orthosilicate (TEOS) and five organosilanes respectively including 3-aminopropyltriethoxysilane (APTES), 3-mercaptopropyltrimethoxysilane (MPTMS), phenyltrimethoxysilane (PTMS), vinyltriethoxysilane (VTES), and 4-(triethoxysilyl)butyronitrile (TSBN), in the presence of nonionic triblock copolymer P123 under acidic synthetic conditions. All the functionalized materials showed an uptake of PGA of almost 90% except for MPTMS-functionalized SBA-15. The glutardialdehyde-activated SBA-15 displayed the highest initial immobilized enzyme activity and the most stable activity among all the support materials. PGA immobilized on VTES-functionalized SBA-15 also showed the highest initial enzyme activity (67.7 Units/mg enzyme), which was much higher than that of the free enzyme (30 Units/mg enzyme).