Microbial Decolorization of Dyes: Evaluating the Potential of Pseudomonas, Bacillus, and Staphylococcus haemolyticus

Synthetic dyes, particularly azo compounds, are widely used in the textile, leather, and allied industries, but their persistence and toxicity present major environmental challenges. Microbial decolorization has emerged as an eco-friendly alternative to conventional physicochemical methods, driven largely by enzyme-mediated pathways. This review comparatively evaluates the dye-degrading potential of Pseudomonas, Bacillus, and Staphylococcus haemolyticus . Pseudomonas spp. are recognized for rapid azo dye degradation (>90% within 12–24 h) but face limitations due to oxygen dependence and pathogenicity concerns. Bacillus spp., with their thermostable and alkali-tolerant enzymes, show 70–85% degradation under alkaline effluent conditions and are well suited for industrial scalability. In contrast, S. haemolyticus, an underexplored candidate, demonstrates dual enzyme activity (azoreductase and laccase), enabling sequential reductive–oxidative degradation and achieving 85–90% decolorization of methyl orange within 24 h and 70–80% Congo red within 36 h. Its adaptability under variable oxygen conditions highlights a unique advantage over conventional bacterial systems. Future prospects lie in integrating omics, enzyme immobilization, nanotechnology, and AI-based bioprocess optimization to enhance efficiency and scalability, while biosafety considerations remain essential. Overall, S. haemolyticus represents a promising next-generation candidate to complement established microbial systems for sustainable wastewater treatment.