Chitosan based metal-chelated copolymer nanoparticles: Laccase immobilization and phenol degradation studies
Yükleniyor...
Tarih
2017
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier Sci Ltd
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Immobilization improves the stability and reusability of enzymes. In this study, laccase, which is a green biocatalyst, was immobilized onto Cu (II)-chelated chitosan nanoparticles via adsorption and successfully applied to remove phenol from aqueous solution. Cu (II)-chelated chitosan-graft-poly (glycidyl methacrylate) nanoparticles were prepared using poly (ethylene imine), PEI, which is employed as both a spacer arm and metal chelator and used to immobilize laccase by coordination. Properties of chitosan based nanoparticles were characterized using FTIR, TGA, SEM and zeta-sizer analysis. The maximum laccase loading capacity of Cu (II)-chelated chitosan based nanoparticles (CHT-PGMA-PEI-Cu (II) NPs) was calculated as 65.75 +/- 2.51 mg/g. This immobilized system exhibited broad pH and temperature profiles, and better stability and reusability than free enzyme; after eight cycles of continuous use, the activity of the immobilized enzyme remained above 50 +/- 0.62%. The K-m and V-max values of free and immobilized laccase were 0.055 mM, 0.070 mM, and 0.19 U/mg, 0.14 U/mg, respectively. The catalytic efficiencies (V-max/K-M) of the free and immobilized laccase were 3.45 and 2.0, respectively. Feasibility of the laccase immobilized system in the removal of phenol was investigated in a batch system. The results showed that the CHT-PGMA-PEI-Cu (II) NPs have great potential for industrial applications. More than 96% of phenol was removed with laccase immobilized metal chelated NPs in the presence of mediator, ABTS, indicating that the metal-chelated chitosan based NPs is a promising support for both laccase immobilization and further applications in the removal of phenolic compounds. (C) 2017 Elsevier Ltd. All rights reserved.
Açıklama
Anahtar Kelimeler
Chitosan, Nanoparticles, Laccase, Cu (II), Phenol
Kaynak
International Biodeterioration & Biodegradation
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
125
Sayı
Künye
closedAccess
