Development of microbial consortium CN-1 for the degradation of Mordant Black 17

An aerobic microbial consortium capable of degrading Mordant Black 17, a mono sulphonated mono azo dye belonging to the most important group of synthetic colorants was constructed using five different bacterial strains isolated from textile effluent and from soil near tannery effluent. The 16S rRNA gene based molecular analysis revealed that the bacterial consortium (CN-1) consisted of five bacterial strains namely, Citrobacter freundii (2 strains), Moraxella osloensis, Pseudomonas aeruginosa and Pseudomonas aeruginosa BL22. The consortium required glucose and ammonium nitrate at a concentration of 0.5% (w/ v) and 0.1% (w/ v) respectively for the maximum decolorization of dye at 37 8C and a pH of 7.5 under shake culture condition bringing about 95% decolorization. The degradation was found to follow first order kinetics with a k1 value of 0.16 h (1). Naphthol, naphthoquinone, salicylic acid and catechol were identified as the intermediates of degradation. This study demonstrates the efficient degradation of Mordant Black 17, a monoazo dye used extensively in textile industries by an aerobic microbial consortium qualifying the consortium as a potential candidate for the biological treatment of dye containing effluent. (C) 2014 Elsevier Ltd. All rights reserved.