Microbial bioremediation strategies for vat dye-contaminated textile effluents: a comprehensive review

Rapid urbanization and industrialization have significantly contributed to water pollution, with the textile industry being a significant source due to its extensive use of synthetic dyes. Among these, VAT dyes, known for their water-insoluble nature, pose substantial challenges in wastewater treatment, mainly due to their resistance to conventional physical and chemical remediation methods. Microbial bioremediation offers a promising, eco-friendly alternative to decolorize and detoxify such dyes. This review examines the biodegradation of VAT dyes in textile effluents, with a focus on microbial pathways and enzymatic mechanisms. It provides a comprehensive overview of the structural properties of VAT dyes, their environmental impact, and the biological processes involved in their degradation. Special attention is given to bacterial, fungal, and algal species capable of effective dye decolorization, along with the roles of critical enzymes like laccases and azoreductases. Challenges in scaling up bioremediation techniques and integrating them into industrial effluent treatment plants are also discussed. The findings of this review aim to bridge gaps in understanding microbial-mediated dye degradation and highlight future directions for sustainable textile wastewater management.