Researchers at the Indian Institute of Technology (IIT) Guwahati and Banaras Hindu University (BHU) have developed an eco‑friendly bacterial method to treat textile wastewater that contains toxic azo dyes, according to a report released on September 16. The study, published in the peer‑reviewed journal Environmental Geochemistry and Health, offers a scientific basis for biological treatment systems that could offer an eco‑friendly alternative or complementary treatment to conventional chemical and physicochemical methods.
The team isolated a novel bacterium, Brevundimonas sp. AJZ05, from a native textile effluent site. The organism produces azoreductase, an enzyme that cleaves the azo bond (–N=N–) that gives dyes their colour and stability. Using a statistical multi‑objective optimisation approach based on Response Surface Methodology, the researchers maximised both dye degradation and enzyme production. The bacterium degraded 98.50 percent of Direct Blue‑6, a widely used synthetic dye, and the resulting metabolites were found to be non‑toxic.
Azo dyes are notoriously resistant to conventional treatment due to their stable chemical structure, and untreated effluents pose risks to aquatic ecosystems and human health. Conventional methods often consume large amounts of energy and can generate secondary pollutants, while colour removal alone does not guarantee the elimination of toxicity.
Looking ahead, the researchers plan to scale up the laboratory findings into a continuous treatment system. Their long‑term goal is to advance the microbial platform toward industrial application, providing a safer and more sustainable approach to wastewater treatment in the textile sector.
