Abstract

Sulfonated azo dyes like Methyl Orange (MO) are widely used in industries such as textiles, paper, food, and printing, but their discharge into wastewater poses a serious threat to aquatic life. This study aimed to isolate and optimize bacterial strains for the bioremediation of MO from textile effluents. Eleven bacterial strains were isolated from industrial effluents in Panipat, India, with Bacillus cereus J4 demonstrating the highest decolorization efficiency, removing up to 98% of MO within 48 hours. To optimize the decolorization process, two methods were employed Plackett–Burman (PB) design and Response Surface Methodology (RSM). PB design identified significant factors affecting decolorization, while RSM provided a more comprehensive optimization by considering interactions among factors. RSM reported an optimal removal rate of 89.8% MO at 50 mg/l dye concentration, pH 7, 37°C, and 2% urea. In conclusion, Bacillus cereus J4 showed promising potential for MO bioremediation under optimized conditions. Future studies should explore scaling up the process and examining the strain’s effectiveness on other industrial dyes to develop a broad-spectrum bioremediation strategy.

Key words: Bacterial strain, Identification, Isolation, Methyl orange, Optimization,