title: Comparison of covalent immobilization of amylase on polystyrene pellets with pentaethylenehexamine and pentaethylene glycol spacers.
abstract: α-Amylase from Aspergillus oryzae was covalently immobilized onto polystyrene pellets with pentaethylenehexamine (PS-PEHA-Ald) and pentaethylene glycol (PS-PG-Ald) carrying a terminal aldehyde group. Optimum immobilization occured at pH 8.0 and 25 °C, and at pH 7.0 and 35 °C for PS-PEHA-Ald and PS-PG-Ald, respectively. PS-PEHA-Ald immobilized enzyme retained approximately 75% of the initial activity over 45 days of storage, 70% of the initial activity after nine runs of recycling and displayed the better resistance to detrimental metal ions. PS-PG-Ald immobilized enzyme retained approximately 50% of the initial activity in 8h at 70 °C. The catalytic efficiencies of PS-PEHA-Ald immobilized and PS-PG-Ald immobilized amylase were 1.42 and 1.29 times higher than that of native enzyme. The activation energy of the reaction mediated by the amylase was reduced by 58.1% and 57.3% when PS-PEHA-Ald and PS-PG-Ald used as support respectively.
authors.affiliation: School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, China. peakwf@hotmail.com
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Gu
authors.forename: Zhenggang
authors.initials: Z
authors.lastname: Cui
authors.forename: Liming
authors.initials: L
authors.lastname: Liu
mesh_terms: D000681:Amylases / Q000737:chemistry*; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D011073:Polyamines / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D013696:Temperature
chemical_list: D004800:Enzymes, Immobilized; D011073:Polyamines; D011137:Polystyrenes; D011092:Polyethylene Glycols; C031122:pentaethylenehexamine; D000681:Amylases