Evaluation of the efficacy of a bacterial consortium for the removal of color, reduction of heavy metals, and toxicity from textile dye effluent

A microbial consortium DAS consisting three bacterial sp. originally obtained from dye contaminated sites of Solapur, India was selected because it was capable of decolorizing textile effluent and dye faster than the individual bacteria under static conditions. Identification of the isolates by 16S rRNA techniques revealed the isolates to be Pseudomonas species. The concerted metabolic activity of these isolates led to complete decolorization of textile effluent as well as Reactive Orange 16 (100 mg l−1) within 48-h at pH 7 and 30 °C. Studies involving Reactive Orange 16 (RO16) dye were carried with the bacterial consortium DAS to elucidate the mechanism of biodegradation. Induction of the laccase and reductase enzyme during RO16 decolorization indicated their role in biodegradation. The biodegradation of RO16 was monitored by using IR spectroscopy, HPLC and GC–MS analysis. Cytotoxicity, genotoxicity and phytotoxicity studies carried out before and after decolorization of the textile effluent revealed the nontoxic nature of the biotreated sample.