Microbial decolorization of a textile azo dye <scp>N</scp> ovacron <scp>B</scp> lue by natural inhabitant bacteria

Abstract Azo dye discharged in wastewater streams from textile or other industry without treatment results in environmental pollution. This study attempts to uncover the ability of naturally occurring bacteria in reducing and decolorizing a textile azo dye Novacron Blue in nutrient medium and also from textile dye effluent. We isolated 13 strains from dye effluent; 3 among them exhibited substantial decolorizing efficacy when coincubated with the dye in minimal salt medium broth, pH 7. We investigated morphological, cultural, biochemical, and physiological characteristics of the efficient strains and identified them as Bacillus megaterium, Corynebacterium rathyi, and Flavobacterium sp. Notably, the organisms showed maximum efficiency at 0.01% dye concentration and in the presence of glucose as cosubstrate at 37°C and acidic to neutral pH following 72 h of incubation. At optimized conditions, all the strains strongly reduce the dye in medium and also from effluent filtrate. Our findings thus imply the potential of naturally occurring bacteria in textile dye biodegradation.