Preparation and Characterization of Chitosan-Coated Manganese-Ferrite Nanoparticles Conjugated with Laccase for Environmental Bioremediation.

Metadata-grounded summary

Citation abstract

Bioremediation with immobilized enzymes has several advantages, such as the enhancement of selectivity, activity, and stability of biocatalysts, as well as enzyme reusability. Laccase has proven to be a good candidate for the removal of a wide range of contaminants. In this study, naked or modified MnFe 2 O 4 magnetic nanoparticles (MNPs) were used as supports for the immobilization of laccase from Trametes versicolor. To increase enzyme loading and stability, MNPs were coated with chitosan both after the MNP synthesis (MNPs-CS) and during their formation (MNPs-CS in situ ). SEM analysis showed different sizes for the two coated systems, 20 nm and 10 nm for MNPs-CS and MNPs-CS in situ, respectively. After covalent immobilization of laccase by glutaraldehyde, the MNPs-CS in situ - lac and MNPs-CS- lac systems showed a good resistance to temperature denaturation and storage stability. The most promising system for use in repeated batches was MNPs-CS in situ - lac, which degraded about 80% of diclofenac compared to 70% of the free enzyme. The obtained results demonstrated that the MnFe 2 O 4 -CS in situ system could be an excellent candidate for the removal of contaminants.