Biodegradation of Cibacron Redazo Dye and Industrial Textile Effluent by Pseudomonas aeruginosa Immobilized on Chitosan-Fe2O3 Composite

Abstract

A bacterial strain (Pseudomonas aeruginosa) having a high capacity for rapid decolourization of the azo dye Cibacron Red was isolated and identified by 16s-rRNA gene sequencing method. The decolorization of cibacron reactive red by free cell under experimental conditions was investigated. At initial dye concentration of 100 ppm, the maximum decolorization percentage (89%) was achieved at pH7, 37ºC under static conditions after 72 h of incubation. The bacterial cells were immobilized on chitosan-magnetite nanoparticles by using glutaraldehyde as a cross-linker. The immobilized cells were used for decolorization of both reactive red dye solution and textile industrial wastewater; a complete decolorization (100%) was achieved after 2 h and 12 h for each treatment, respectively. The dye biodegradation products were identified by GC/MS analysis and determination of laccase, peroxidase and dioxygenase enzyme activities in the bacterial supernatant. The obtained results from this work are expected to be a useful reference for development of effective decolorization bioprocesses utilizing immobilized bacterial cells as a biocatalyst and also to demonstrate feasible operation strategies to utilize the immobilized-cell as a fixed bed for efficient decolorization of dye-laden wastewaters.