Efficient Decolorization of Dye Acid Blue 113 by Soil Bacterium <i>Bacillus subtilis</i> RMLP2

Abstract

In this study, a bacterial strain was isolated from soil and tested for the decolorization of azo dye Acid Blue 113 (AB 113). Decolorization of azo dyes by means of physico-chemical method is not environmentally friendly thus an alternative method based on bacteria was employed for decolorization of AB 113. The color removal studies were performed using Bushnell and Hass medium amended with AB 113 dye. Bacterial isolate Bacillus subtilis RMLP2 was identified by 16S rRNA gene sequence analysis. The effect of various physico-chemical parameters such as incubation condition, pH, temperature, carbon source, nitrogen source and dye concentration on decolorization of AB 113 by Bacillus subtilis RMLP2 were studied. The bacterial isolate showed the remarkable higher percentage (92.71%) of color removal of dye AB 113 at 100 mg/L concentration, 35oC, pH 7 during 72 h of incubation period under static condition. Yeast extract and glucose was found as best nitrogen and carbon source for efficient decolorization of dye. These results confirmed that the Bacillus subtilis has enormous ability to degrade dye AB 113 present in textile effluents.