title: Immobilization of glucoamylase onto polyaniline-grafted magnetic hydrogel via adsorption and adsorption/cross-linking.
abstract: Glucoamylase (GA) was immobilized onto polyaniline (PANI)-grafted magnetic poly(2-hydroxyethylmethacrylate-co-glycidylmethacrylate) hydrogel (m-p(HEMA-GMA)-PANI) with two different methods (i.e., adsorption and adsorption/cross-linking). The immobilized enzyme preparations were used for the hydrolysis of "starch" dextrin. The amount of enzyme loading on the ferrogel was affected by the medium pH and the initial concentration of enzyme. The maximum loading capacity of the enzyme on the ferrogel was found to be 36.7 mg/g from 2.0 mg/mL enzyme solution at pH 4.0. The adsorbed GA demonstrated higher activity (59%) compared to adsorbed/cross-linked GA (43%). Finally, the immobilized GA preparations exhibited greater stability against heat at 55 °C and pH 4.5 compared to free enzyme (50 °C and pH 5.5), suggesting that the ferrogel was suitable support for immobilization of glucoamylase.
authors.affiliation: Biochemical Processing and Biomaterial Research Laboratory, Faculty of Science, Gazi University, 06500, Teknikokullar, Ankara, Turkey. g_bayramoglu@hotmail.com
authors.forename: Gulay
authors.initials: G
authors.lastname: Bayramoglu
authors.forename: Begum
authors.initials: B
authors.lastname: Altintas
authors.forename: M Yakup
authors.initials: MY
authors.lastname: Arica
mesh_terms: D000327:Adsorption; D000814:Aniline Compounds / Q000737:chemistry*; D001709:Biotechnology / Q000379:methods*; D003912:Dextrins / Q000378:metabolism; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism; D005087:Glucan 1,4-alpha-Glucosidase / Q000737:chemistry* / Q000378:metabolism; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008280:Magnetics; D013696:Temperature
chemical_list: D000814:Aniline Compounds; D003912:Dextrins; D004800:Enzymes, Immobilized; C416807:polyaniline; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D005087:Glucan 1,4-alpha-Glucosidase