Modification and characterization of natural aluminosilicates, expanded perlite, and its application to immobilise α – amylase from A. oryzae.

Publication date: Available online 18 January 2017 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): J. Rodriguez, F. Soria, H. Geronazzo, H. Destefanis The aim of this study was to modify natural silicoaluminates as expanded perlite (EP) through simple and inexpensive treatments in order to get a greater reactivity of surface and immobilise α-amylase from A. oryzae by adsorption and covalent binding. The materials obtained (expanded perlite treated with HCl, rehydroxylated expanded perlite, zeolite, and the incorporation of polystyrene in expanded perlite) were analysed by infrared spectroscopy, thermal analysis, zeta potential, adsorption of N2, and Scanning Electron Microscopy. The analysis allowed us to confirm that the modifications on the materials studied were effective. This is perceived by an increase in bands corresponding to OH groups, which is beneficial when considering functional groups that interact directly with the enzyme. It also allowed us to determine that the materials tested exhibit good thermal stability at the temperature range in which enzymatic studies are conducted. The conditions for immobilisation (pH, concentration of glutaraldehyde, time of contact between the enzyme and the substrate, enzyme concentration) and some properties of the immobilised derivatives (optimum pH, temperature of maximum activity, and reuse) were analysed. The suitable range for the immobilisation of α-amylase from A. oryzae by covalent binding was pH be...

Source: Journal of Molecular Catalysis B: Enzymatic - January 17, 2017 Category: Biochemistry Source Type: research