Assessment of biological decolorization and degradation of sulfonated di-azo dye Acid Maroon V by isolated bacterial consortium EDPA

The present study deals with the decolorization of di-azo dye Acid Maroon V by consortium EDPA comprised of two isolates obtained from a contaminated site. The two isolates Enterobacter dissolvensAGYP1 and Pseudomonas aeruginosaAGYP2 were identified based on 16S rDNA sequencing. 93% decolorization of dye (100 mg l−1) was observed in Mineral Salt Medium in 20 h under static incubation condition. The consortium retained a decolorization activity over a wide range of pH values (6.0–9.0) with peak activity at pH 7.0. Additionally, consortium decolorized relatively high concentrations of Acid Maroon V (100–2000 mg l−1). The addition of sucrose co-substrate plus ammonium dihydrogen phosphate increased decolorization rate. The degradation of the dye was confirmed using spectrophotometric analysis, HPTLC and FTIR. The consortium was also able to reduce COD by 31% within 20 h. Acid Maroon V metabolites produced by consortium EDPA were considerably less phytotoxic than the parent compound. The consortium had the ability to decolorize 16 other textile dyes. These results suggest that the consortium EDPA is suitable for biological processing of dye containing wastewaters.

► Consortium EDPA (Enterobacter dissolvensAGYP1 + Pseudomonas aeruginosaAGYP2) decolorizes azo dye Acid Maroon V. ► Up to 2000 mg l−1 are degraded in a mineral medium (static culture, pH 7.0, 30 °C). ► Dye degradation confirmed by HPTLC and FTIR. ► Metabolites are considerably less phytotoxic than Acid Maroon V. ► The consortium decolorized 16 other textile dyes.