Lipase Immobilization Onto Polyethylenimine Coated Magnetic Nanoparticles Assisted by Divalent Metal Chelated Ions Publisher



Motevalizadeh SF^{1, 2} ; Khoobi M¹ ; Sadighi A³ ; Khalilvandsedagheh M¹ ; Pazhouhandeh M⁵ ; Ramazani A⁴ ; Faramarzi MA⁵ ; Shafiee A¹
Source: Journal of Molecular Catalysis B: Enzymatic Published:2015

Abstract

In this study, polyethylenimine coated Fe3O4 magnetic nanoparticles (Fe@PEI) were prepared and used for three metal ions (Co2+, Cu2+ and Pd2+) chelation. The metal chelated magnetic nanoparticles (Fe@PEI-M) were characterized by using different spectroscopic and analytical techniques. The metal contents were analyzed by inductively coupled plasma atomic emission spectroscopy (ICP) and energy-dispersive X-ray spectroscopy (EDX). Thermomyces lanuginosa lipase (TLL) was then immobilized onto the modified magnetic supports by physical adsorption. Fe@PEI-Co and Fe@PEI-Cu showed better activity at extreme temperature and pH values than of the free enzyme. After 10 cycles of successful biocatalytic activity performed by immobilized lipase on Fe@PEI-Co, more than 60% of initial activity was reserved. Furthermore, the immobilized lipase onto Fe@PEI-Co retained about 80% of its initial activity after 14 days of storage. The immobilized lipase on the selected nanocomposite was then used for synthesis of ethyl valerate. After 24 h incubation time, the extent of esterification was found to be 70 and 60% in n-hexane and DMSO media, respectively. © 2015 Elsevier B.V. All rights reserved.