STRATEGIC OPTIMIZATION OF FERMENTATION PARAMETERS FOR BACILLUS SUBTILIS MEDIATED AZO DYE TREATMENT

Azo dyes, widely used in the textile industry, pose significant environmental concerns due to their toxicity, potential carcinogenicity, and impact on aquatic ecosystems. Similarly, coffee dye, a natural pigment released from coffee-processing industries, contributes to organic pollution, oxygen depletion, and discoloration of water bodies. Bacillus subtilis has emerged as a promising microorganism for the bioremediation of both azo and coffee dyes, offering a sustainable and eco-friendly solution. This study provides a comprehensive overview of the current knowledge on optimizing cultural conditions for dye decolorization by B. subtilis. Key factors such as pH, temperature, dye concentration, carbon and nitrogen sources, redox mediators, and incubation time are discussed for enhancing decolorization efficiency. The enzymatic mechanisms involved—including azoreductases, laccases, and peroxidases—are also examined. B. subtilis demonstrates effective degradation of complex dye structures in both synthetic azo dyes and natural coffee dyes, making it a versatile agent for industrial bioremediation. The study further explores future research directions, including genetically engineered strains, immobilization techniques, and integrated treatment systems, along with the importance of phytotoxicity and microbial toxicity assessments. Overall, this study highlights the bioremediation potential of Bacillus subtilis for treating diverse dye-containing effluents.