DECOLOURIZATION OF AZO DYE BY NATIVE MICROBIAL CONSORTIUM

Abstract

The present study was focused on decolourization of textile azo dyes by using native bacterial consortium isolated from textile dye effluent. The bacterial isolates were screened for dye decolourising capability in Bushnell Hass medium. Potent five isolates (KTE7, KTE28, KTE48, KTE64 and KTE83) out of 95 total isolates were selected for efficient dye decolouration using spot assay method. Best dye decolouration was noted with KTE7 and KTE 28. These five isolates were subjected for microbial characterization, which reveals the presence of Bacillus cereus (KTE7), Pseudomonas fluorescence (KTE28), Staphylococcus aureus (KTE48), Escherichia coli (KTE64) and Lactobacillus sp., (KTE83). The decolorization was optimized under different parameters like growth temperature, incubation time and pH. The nutritional supplementation was carried out using various carbon and nitrogen sources to enrich the production medium to enhance microbial decolouration. Mixed cultures in 10 combinations and consortium of all five strains also used for assessing dye decolourizing efficiency. Among the mixed culture combination Bacillus + Pseudomonas combination produced 97.84% dye decolouration within 8 days of incubation. Similarly corsortium of five microbial agents efficiently decolourized azo dye up to 83.26 within four days of incubation, which is evidenced in FTIR report.