title: Physical and chemical adsorption of Mucor javanicus lipase on SBA-15 mesoporous silica. Synthesis, structural characterization, and activity performance.
abstract: In this work a sample of SBA-15 mesoporous silica was synthesized and characterized by TEM, XRD, and N2 adsorption. The sample had a high value of specific surface area (1007 m2 g(-1)) and total pore volume (2.1 cm3 g(-1)). The pore diameter was 67 angstroms, so it was large enough to accommodate protein molecules inside the channels. Immobilization by physical adsorption of a commercial lipase preparation from Mucor javanicus was performed at different pH values (pH 5-8). pH 6 gave the highest lipase loading and hydrolytic activity of the corresponding biocatalyst. Chemical modification of the SBA-15 via glutardialdehyde allowed also the enzyme immobilization through chemical adsorption. This preparation was active toward tributyrin hydrolysis. On the contrary, very low activity toward triolein hydrolysis was observed. The reduction of the size of the channels due the immobilization process has been suggested as a possible explanation.
authors.affiliation: Department of Chemical Sciences, University of Cagliari, S.S. 554 Bivio Sestu 09042 Monserrato (CA), Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Salis
authors.forename: Daniela
authors.initials: D
authors.lastname: Meloni
authors.forename: Stefania
authors.initials: S
authors.lastname: Ligas
authors.forename: Maria F
authors.initials: MF
authors.lastname: Casula
authors.forename: Maura
authors.initials: M
authors.lastname: Monduzzi
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Solinas
authors.forename: Emil
authors.initials: E
authors.lastname: Dumitriu
mesh_terms: D000327:Adsorption; D004800:Enzymes, Immobilized / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008049:Lipase / Q000737:chemistry* / Q000378:metabolism; D008956:Models, Chemical; D009089:Mucor / Q000201:enzymology*; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D004800:Enzymes, Immobilized; C509969:SBA-15; D012822:Silicon Dioxide; D008049:Lipase