Biodecolorization of azo dye mixture (Remazol Brilliant Violet 5R and Reactive Red 120) by indigenous bacterial consortium isolated from dye contaminated soil

ABSTRACT

Aims@#The present study investigated the biodegradation and removal of dye mixture (Remazol Brilliant Violet 5R and Reactive Red 120) using a new bacterial consortium isolated from dye-contaminated soil.@*Methodology and results@#Among the total 15 isolates screened, the two most efficient bacterial species (SS07 and SS09) were selected and identified as Enterobacter cloacae (MT573884) and Achromobacter pulmonis (MT573885). The removal efficiency of dye mixture by E. cloacae and A. pulmonis at an initial concentration of 100 mg/L was 82.78 and 84.96%, discretely. The bacterial consortium was developed using selected isolates and the optimum conditions for removing dyes were investigated. The maximum decolorization efficiency was achieved at pH 7; 35 °C; dye concentration, 100 mg/L; and initial inoculum concentration, 0.5 mL with mannitol and ammonium sulfate as carbon and nitrogen sources. The maximum removal efficiency of 91.3 ± 3.35% was achieved at the optimal conditions after 72 h of incubation.@*Conclusion, significance and impact of study@#Decolorization of azo dyestuff by the developed microbial consortia conforms to the zero-order reaction kinetics model. Consortia of E. cloacae and A. pulmonis was established as an effective decolorizer for the Remazol Brilliant violet 5R and Reactive Red 120 dye mixture with >90% color removal.