Immobilization of Fungal Peroxidase on Paramagnetic Nanoparticles for Synthetic Dye Decolorization

Peroxidase was produced by a fungal isolate identified as Aspergillus flavus KIGC through ITS sequence and phylogenetic analysis on 11^th day of fermentation when grown on banana peel as the sole carbon source. It was purified through ammonium sulphate, ion exchange including gel filtration. The peroxidase was purified to 8.86 folds with percentage recovery of 49.72%. The purified enzyme was a monomer of 57KDa. The purified peroxidase was immobilized on iron oxide magnetic nanoparticle and characterized using DLS, DSC, XRD, FTIR and SEM analyses. The characterization results suggest adequate nanoparticle formulation and effective enzyme immobilization therein. Optimal temperatures for both free and immobilized peroxidase were 75 and 70 °C, respectively, while the optimum pH peaks at 5.0 and 9.0 were obtained for free enzyme and 6.5 and 9.0 for immobilized peroxidase, respectively. The Michealis constant (K_m) of 0.075mM and catalytic efficiency (turnover rate) of 90.66 Mol/S^-1 were achieved by the immobilized peroxidase on guaiacol as substrate. The immobilized enzyme showed relatively high residual activity in towards ethanol > acetone > DMSO > methanol > Chloroform, respectively. Furthermore, metallic nanoparticle immobilized peroxidase exhibited an enhanced synthetic dyes decolorizationability compared to the free enzyme. The immobilization of peroxidase produced using organic waste as carbon source on iron oxide magnetic nanoparticles conferred considerable stability on the enzyme with great potential for various industrial applications.