Bioremediation of Textile Reactive Blue Azo Dye Residues using Nanobiotechnology Approaches.

Abstract

Microbial cells contain wide assortment of specific enzymes capable to biodegrade various organic chemicals, Lignin peroxidase (LiP) plays an important role in biodegradation and mineralization of recalcitrant aromatic compounds, polychlorinated biphenyls and dyes. This study focuses on bioremediation of Reactive Blue azo dye residues generated from textile dye basins. Immobilization and stabilization of lignin peroxidase enzyme form potential bioremediation bacterial strain was among the nanobiotechnological approaches tested in this study. The lignin peroxidase enzyme isolated from Pseudomonas aeruginosa strain OS4 was partially purified. The enzyme purity was checked using SDS/PAGE. The results showed single band on gel having the molecular weight of approximately 38 kDa. Magnetic (Fe3O4) nanoparticles were prepared by coprecipitation technique. The size and shape of Fe3O4 was examined by TEM and the average particles size was 16- 20 nm. The surface charges of Fe3O4 magnetic nanoparticles were modified using glutaraldehyde as crosslinker to modify the nanoparticles surface for conjugation with the enzyme. The active groups support the covalent bioconjucation properties necessary for enzyme immobilization. The modified Fe3O4 nanoparticls were used for immobilization and stabilization of LiP enzyme as well as whole bacterial cells. The immobilized enzyme on magnetic nanoparticles performed much better than free enzyme in decolourization of the dye residues. The repeated use of the enzyme linked to magnetic nanoparticle is very promising for environmental application.