Enzymatic biodegradation and detoxification of azo and anthraquinone dyes by indigenously isolated bacterial monocultures and their synergistic behaviour in developed consortia

Wastewater generated by textile industry needs to be treated to reduce its toxicity before final disposal and/or for recycling purposes. In the current study, several bacterial strains were screened for dye decolorization potential. UV–visible spectroscopy was used to determine maximum absorption wavelength of disperse dyes. HPLC and MTS assay were used to confirm the degradation and detoxification of disperse dyes, respectively. Results revealed that indigenously isolated Bacillus licheniformis, Glutamicibacter uratoxydans and Pseudomonas aeruginosa showed strong decolorization of red, blue and violet, respectively in 6–9 h. MTS assay revealed 100% viability of NIH/3T3 cell lines in presence of treated dyes. Enzyme screening assay confirmed the production of intracellular and membrane bound oxidoreductases in presence of specific dye as substrate. To resolve this issue, bacterial consortia were prepared, and better decolorization of all dyes was achieved in synergistic behaviour of Consortia 1 and 4 with 85% and 88% decolorization potential, respectively.