Bioremediation of polyaromatic hydrocarbon polluted sewage sludge soil employing a bacterial consortium and phytotoxicity evaluation.

This article focuses on the evaluation of a bacterial consortium’s ability to biodegrade polyaromatic hydrocarbons (PAHs) in sewage sludge collected from wastewater treatment plants (WWTPs) in India. The consortium, consisting of five characterized bacterial strains—Stenotrophomonas maltophilia IITR87, Ochrobactrum anthropi IITR07, Microbacterium esteraromaticum IITR47, Pseudomonas aeruginosa IITR48, and Pseudomonas mendocina IITR46—achieved 60%–70% degradation of PAHs within 20 days under microcosm conditions, with enhanced breakdown of low molecular weight PAHs. Phytotoxicity assessments using wheat (Triticum aestivum), black chickpea (Cicer arietinum), and mustard (Brassica juncea) demonstrated significant reduction in toxicity and improved plant growth in remediated sludge compared to contaminated samples. The study suggests that bioaugmentation with this bacterial consortium offers a promising bioremediation strategy to reduce ecological risks posed by PAHs in complex sewage sludge environments.