Unveiling triclosan biodegradation: Novel metabolic pathways, genomic insights, and global environmental adaptability of Pseudomonas sp. strain W03

The polychlorinated aromatic antimicrobial agent triclosan (TCS) is widely used to indiscriminately and rapidly kill microorganisms. The global use of TCS has led to widespread environmental contamination, posing significant threats to ecosystem and human health. Here we reported a newly isolated Pseudomonas sp. W03 for degrading TCS metabolically at concentrations up to 10 mg/L. This strain exhibited optimal degradation activity at 30°C and pH 7.0, and retained substantial activity at pH 4.0, although it was sensitive to alkaline conditions. Genomic analysis of strain W03 revealed a circular chromosome comprising 6,075,907 bp with a GC content of 65.08%. A novel TCS degradation pathway, involving dechlorination, oxidation, ether bond fission, and reoxidation processes, was identified. Also, the study mapped the global distribution of analogous Pseudomonas using 16S rRNA gene sequences, revealing their widespread presence in diverse aquatic environments, with a significant abundance in wastewater systems. These findings indicated that these bacteria play a critical ecological role in both natural and engineered environments, particularly in the degradation of organic pollutants. This study enhances our understanding of microbial degradation of emerging contaminants and presents a promising candidate for bioremediation strategies aimed at mitigating TCS-related water pollution.