Adsorption equilibrium, kinetics and thermodynamics of alpha-amylase on poly(DVB-VIM)-Cu+2 magnetic metal-chelate affinity sorbent

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Date

2012-09

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Springer

Abstract

Designing an immobilised metal ion affinity process on large-scale demands that a thorough understanding be developed regarding the adsorption behaviour of proteins on metal-loaded gels and the characteristic adsorption parameters to be evaluated. In view of this requirement, interaction of alpha-amylase as a model protein with newly synthesised magnetic-poly(divinylbenzene-1-vinylimidazole) [m-poly(DVB-VIM)] microbeads (average diameter, 53-212 mu m) was investigated. The m-poly(DVB-VIM) microbeads were prepared by copolymerising of divinylbenzene (DVB) with 1-vinylimidazole (VIM). The m-poly(DVB-VIM) microbeads were characterised by N-2 adsorption/desorption isotherms, electron spin resonance, elemental analysis, scanning electron microscope and swelling studies. Cu2+ ions were chelated on the m-poly(DVB-VIM) beads and used in adsorption of alpha-amylase in a batch system. The maximum alpha-amylase adsorption capacity of the m-poly(DVB-VIM)-Cu2+ beads was determined as 10.84 mg/g at pH 6.0, 25 A degrees C. The adsorption data were analyzed using three isotherm models, which are the Langmuir, Freundlich and Dubinin-Radushkevich isotherm models. The pseudo-first-order, pseudo-second-order, modified Ritchie's-second-order and intraparticle diffusion models were used to test dynamic experimental data. The study of temperature effect was quantified by calculating various thermodynamic parameters such as Gibbs free energy, enthalpy and entropy changes.

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Keywords

Biochemistry & molecular biology, Biotechnology & applied microbiology, Immobilised metal ion affinity, Ima, Protein adsorption, Alpha-amylase, Magnetic beads, Aqueous-solution, Ions, Immobilization, Beads, Proteins, Removal, Zn(II), Matrix, Water, Adsorption isotherms, Amylases, Chelation, Dyes, Free energy, Gibbs free energy, Magnetic moments, Metal ions, Metals, Scanning electron microscopy, Adsorption capacities, Adsorption equilibria, Intraparticle diffusion models, Kinetics and thermodynamics, Magnetic beads, Metal ion affinities, Thermodynamic parameter, Adsorption

Citation

Osman, B. vd. (2012). "Adsorption equilibrium, kinetics and thermodynamics of alpha-amylase on poly(DVB-VIM)-Cu+2 magnetic metal-chelate affinity sorbent". Applied Biochemistry and Biotechnology, 168(2), 279-294.