Biodegradation of Carcinogenic Reactive Azo Dyes by Indigenous Bacterial Consortium X5RC5

Abstract

Reactive azo dyes are considered as a major source of water and soil contamination. Carcinogenicity and the recalcitrant nature of these dyes is a worldwide problem. Exclusion of these dyes from the effluent is necessary for a clean and green environment. A bacterial consortium X5RC5 was developed for the effective removal of two of the primary reactive azo dyes utilized widely in textile industries (reactive orange 3R and reactive red HE7B). The consortium includes two indigenous bacterial isolates, Lysinibacillus macroides and Stenotrophomonas acidaminiphila, from textile effluent. The X5RC5 completely degraded the reactive orange 3R in 4 days and reactive red HE7B in 5 days of incubation periods. In two days, more than 50% degradation was observed for both dyes. Biodegradation of these dyes was affirmed through the UV-Vis spectra and Fourier-transform infrared spectroscopy (FTIR) analysis. This investigation advances the utilization of consortium X5RC5 as a biological tool for the bio-handling of effluent containing dyes.