abstract
Developments in nanotechnology have led to the discovery of new materials, namely, magnetic nanoparticles (MNPs), that present easy surface functionalization and high surface-to-volume ratios. These properties allow a high mass transfer rate and easy removal from a reaction matrix. Simple separation under an external magnetic field makes them a promising immobilization support for enzymes. In this work, new MNPs were prepared by functionalization with EDTA-TMS and characterized by TEM, FTIR and BET analytical techniques, among others. These MNPs were applied as support for laccase immobilization to create a promising biocatalyst. Despite the known chelating nature of EDTA-TMS, its use for surface modification of MNPs for laccase immobilization is a rather unexplored strategy and is reported here for the first time. At pH 3.5, the immobilization process showed approximately 97% of enzymatic activity recovery. The Michaelis-Menten kinetic properties of immobilized laccase showed a lower Vmax and a similar KM compared to free laccase. Regarding operational stability, the immobilized enzyme presented approximately 73% of its initial activity after five sequential reactive cycles. The immobilized enzyme was successfully applied to the biocatalysis of Indigo Carmine dye degradation. These MNPs with immobilized laccase showed important advantages compared to other materials for application in industrial biochemical processes, biocatalysis and biosensors.
keywords
FUNGAL LACCASES; COMMERCIAL LACCASE; EFFLUENT TREATMENT; CARBON NANOTUBES; SYNTHETIC DYES; DECOLORIZATION; REMOVAL; ENZYME; 2,4-DICHLOROPHENOL; PERFORMANCE
subject category
Engineering
authors
Fernandes, RA; Daniel-da-Silva, AL; Tavares, APM; Xavier, AMRB
our authors
Ana Luísa Daniel da Silva
Principal Researcher
Ana Maria Rebelo Barreto Xavier
Assistant Professor
Ana Paula Mora Tavares
Assistant ResearcherGroups
G1 - Porous Materials and Nanosystems
G4 - Renewable Materials and Circular Economy
G5 - Biomimetic, Biological and Living Materials
acknowledgements
This work was developed within the scope of the CICECO-Aveiro Institute of Materials project, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), financed by national funds through the FCT/MEC and, when appropriate, co-financed by FEDER under the PT2020 Partnership Agreement. Ana P.M. Tavares acknowledges FCT Portugal for Postdoctoral Fellowship (SFRH/BPD/109812/2015). Ana L. Daniel-da-Silva acknowledges FCT for the IF-2014 FCT Investigator Programme. The authors thank the RNME (National Electronic Microscopy Network) for the use of their microscopy facilities.