Optimization of conditions for the biological treatment of textile dyes using isolated soil bacteria

Abstract

Background: In the 21st century, environmental pollution has been acknowledged as one of the major problems. The textile and dyeing industries contribute a major portion by discharging intensely complex effluent consisting of highly noxious azoic dyes. Methods: In this study, biological treatment using acclimatized microorganisms were employed in search of a cheap and eco-friendly substitute for color removal from textile waste. The microbial inocula were isolated from effluent soil samples and then applied to flasks containing azo dyes as the only source of carbon for decolorization. Results: Biochemical tests postulated predominance of Enterococcus and Bacillus bacterial strains. CO isolate or Bacillus farraginis emerged as the best decolorizer of Orange M2R dye, decolorizing 98% of the dye.  BG isolate or Paenibacillus macerans showed maximum decolorization on Green GS dye that decolorized 97% of the dye. The optimum physiochemical condition for decolorization of OM2R and GGS dye was pH 7.0, 2% NaCl conc., 1% initial dye conc. and 37°C temperature by the selected isolates. Conclusions: The findings were validated and have the potential for bioremediation in textile waste effluent treatment plants.