Decolorization of Black WNN dye with Staphylococcus epidermidis MTCC 10623

Wastewater from the textile and other dye stuff industries contain significant quantity of synthetic dyes that require treatment to prevent ground water contamination. In recent years, the ability of microorganism to decolorize textile wastewater has received great attention due to environmental persistence and toxicity of these pollutants. Decolorization of Black WNN dye by Staphylococcus epidermidis MTCC 10623 was examined under static and shaking conditions. S. epidermidis MTCC 10623 isolated from the contaminated soil of textile dyeing industry, was characterized morphologically and biochemically. Effect of various process parameters such as pH (6-10), temperature (25- 45°C), dye concentration (50-250ppm) and inoculums concentration were investigated and maximum decolorization (97%) of Black WNN dye (100ppm) was achieved at pH 9, temperature 35°C with 10% of inoculum concentration. UV-vis analysis of Black WNN dye control and metabolites produced after decolorization showed the complete degradation of dye. Phytotoxicity studies revealed that product formed after decolorization with S. epidermidis MTCC 10623 were of non-toxic in nature and suggest that this bacterium is the efficient azodye degrading bacteria and has practical application in biological treatment of dye-polluted wastewater streams, which results the less amount of sludge formation along with good degree of mineralization.