Laccase Immobilization on Copper-Magnetic Nanoparticles for Efficient Bisphenol Degradation

Abstract

Laccase activity is influenced by copper (Cu) as an inducer. In this study, laccase was immobilized on Cu and Cu-magnetic (Cu/Fe 2 O 4 ) nanoparticles (NPs) to improve enzyme stability and potential applications. The Cu/Fe 2 O 4 NPs functionally activated by 3-aminopropyltriethoxysilane and glutaraldehyde exhibited an immobilization yield and relative activity (RA) of 93.1 and 140%, respectively. Under optimized conditions, Cu/Fe 2 O 4 NPs showed high loading of laccase up to 285 mg/g of support and maximum RA of 140% at a pH 5.0 after 24 h of incubation (4°C). Immobilized laccase, as Cu/Fe 2 O 4 -laccase, had a higher optimum pH (4.0) and temperature (45°C) than those of a free enzyme. The pH and temperature profiles were significantly improved through immobilization. Cu/Fe 2 O 4 -laccase exhibited 25-fold higher thermal stability at 65°C and retained residual activity of 91.8% after 10 cycles of reuse. The degradation of bisphenols was 3.9-fold higher with Cu/Fe 2 O 4 -laccase than that with the free enzyme. To the best of our knowledge, Rhus vernicifera laccase immobilization on Cu or Cu/Fe 2 O 4 NPs has not yet been reported. This investigation revealed that laccase immobilization on Cu/Fe 2 O 4 NPs is desirable for efficient enzyme loading and high relative activity, with remarkable bisphenol A degradation potential.

Enhanced Laccase Activity and Stability as Crosslinked Enzyme Aggregates on Magnetic Copper Ferrite Nanoparticles for Biotechnological Processes

“…Patel et al. reported the covalent conjugation of laccase ( R. vernicifera ) on amine‐functionalized copper containing magnetic nanoparticles (Cu/Fe 2 O 4 NPs) with 140 % activity recovery and observed ~1.4‐fold higher V max of immobilized enzyme [17] . In the case of m‐CLEAS, Kumar et al.…”

“…[13] Patel et al reported the covalent conjugation of laccase (R. vernicifera) on amine-functionalized copper containing magnetic nanoparticles (Cu/Fe 2 O 4 NPs) with 140 % activity recovery and observed ~1.4-fold higher V max of immobilized enzyme. [17] In the case of m-CLEAS, Kumar et al reported ~4.5fold higher catalysis of m-CLAES of laccase (T. versicolor) on MNPs resulting in 8-fold higher catalytic efficiency. [25] While other reports mentioned decreased laccase activity after immobilization on MNPs as m-CLEAS.…”

“…[15,16] In recent work, copper ferrite (CuFe 2 O 4 ) magnetic nanoparticles (CFNPs) with a functional layer of 3-aminopropyltriethoxysilane (APTES) are used to immobilize laccase by covalent conjugation using glutaraldehyde as a cross-linker. [13,17] The laccase showed superior kinetic potential and stability. Moreover, CFNPs are well known for their photocatalytic properties, and Fenton-like reactions, consequently, are also applied in the degradation of organic pollutants present in wastewater.…”

“…In fact, various copper‐based nanomaterials are reported to significantly improve the enzymatic activity [15,16] . In recent work, copper ferrite (CuFe 2 O 4 ) magnetic nanoparticles (CFNPs) with a functional layer of 3‐aminopropyltriethoxysilane (APTES) are used to immobilize laccase by covalent conjugation using glutaraldehyde as a cross‐linker [13,17] . The laccase showed superior kinetic potential and stability.…”

Nanocatalytic performance of pectinase immobilized over in situ prepared magnetic nanoparticles

“…Moreover, magnetic nanoparticles have been researched to reuse enzymes due to their biocompatibility [ 15 ]. However, the residual activity of the immobilized enzyme can be affected by enzyme inactivation after the recycling process [ 16 ]. Numerous enzymes have been immobilized on Fe 3 O 4 , including cholesterol oxidase, laccase, amylase, lipase, and pectinase [ 17 , 18 ].…”