Abstract
Trifluralin, a widely utilized dinitroaniline herbicide, has emerged as a prevalent environmental contaminant that poses significant risks both to ecosystems and to human health. Microbial degradation represents the primary pathway for preventing trifluralin accumulation in the environment. Although much work has been conducted on the microbial breakdown of trifluralin, numerous challenges persist regarding the identification of efficient degrading strains, the elucidation of the metabolic pathways involved, and the application of bioremediation techniques. In this study, Bacillus sp. TF-1, a strain isolated from a paddy field that can utilize trifluralin as a source of carbon and energy, was applied. Remarkably, it eliminated 86.7% of 100 mg/L trifluralin within 6 h, and 99.7% of trifluralin was eliminated within 48 h. UPLC-MS analysis suggested that trifluralin degradation occurred first through mono-nitroreduction, followed by further nitroreduction and trifluoromethyl oxidation; trifluralin could also be metabolized through complete nitroreduction and N-dealkylation. Furthermore, Bacillus sp. TF-1 effectively mitigated the severe toxicity of trifluralin to sensitive crops. These findings not only expand the repertoire of efficient trifluralin-degrading microorganisms but also increase our understanding of trifluralin biodegradation pathways and highlight the biological importance of employing microbes to eradicate trifluralin residues from the environment.