Effective decolorization of Direct blue-1 dye by Bacillus cereus isolate for its possible application in environmental sustainability

Azo dyes which are found in the textile wastewater are one of the major environmental contaminants which pose threats for healthy ecosystem. Industrial developments resulted in the surge of dye contaminated wastewater, therefore, creating global environmental concern due to the intricate structure of dyes. Bacterial remediation of dyes from contaminated aquatic systems is an environmentally friendly approach. The aim of this study was isolation and identification of a bacterial strain with the potential of decolorizing an azo dye, Direct Blue-1, from dye-laden wastewater, and optimization of process parameters to achieve maximum level of dye decolorization. Total 9 bacterial cultures were isolated at 50 mg/l dye concentration from dye-contaminated wastewater. While single bacterial isolate was capable to decolorize Direct Blue-1 dye at 200 mg/l in minimal salt agar medium. Morphological, biochemical and 16S-rRNA gene sequence analysis showed that the isolated bacterium was Bacillus cereus strain MT-4. A Maximum of 97% decolorization was achieved at 5% v/v of inoculum size, under optimized cultural condition. The study highlights the potential of these bacterial strains in effective removal of Direct Blue-1, and their possible applications for clean and sustainable aquatic environment.