Bioprospecting of bacteria from textile effluents for enhanced dye biodegradation

The textile industry is a major contributor to water pollution, releasing effluents containing 10-15% unused synthetic dyes. These dyes have complex aromatic structures that resist biodegradation, posing serious risks to aquatic ecosystems and human health. This study evaluated the physicochemical properties of wastewater from the Maa Garment Textile Factory and investigated the bioremediation potential of indigenous bacterial isolates. Effluent samples collected from different treatment points were analyzed for pH, temperature, total suspended solids (TSS), total dissolved solids (TDS), biological oxygen demand (BOD), and chemical oxygen demand (COD). The wastewater exhibited a neutral to slightly alkaline pH (7.2-7.5), favorable for microbial activity, but had elevated temperatures (up to 38 °C) and high TDS (2633-2866 mg/L), indicating thermal and chemical pollution. A total of 30 bacterial isolates were screened for their ability to biodegrade reactive red, blue, and yellow dyes under varying conditions of temperature (25-40 °C), pH (5-9), and dye concentration (50-150 mg/L). Sixteen isolates demonstrated biodegradation capacity, with optimal performance (mean 89.4%) observed at 37 °C, pH 7, and 50 mg/L dye concentration, and significant variation across tested conditions (p < 0.001). The effective isolates included Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Shigella species, and Salmonella Typhimurium. Among them, P. aeruginosa strains (H5P, C2P, and C4P) showed the highest efficiency, achieving up to 90% biodegradation and maintaining strong performance under alkaline conditions (pH 9) and higher dye concentrations (150 mg/L). These findings highlight the adaptability of indigenous bacteria for dye degradation and identify P. aeruginosa as a promising candidate for sustainable, cost-effective industrial bioremediation, although further field validation across diverse dye systems is recommended.