Biotransformation of perfluorooctanoic acid by a newly isolated Stenotrophomonas acidaminiphila OA1 strain from Quebec

Perfluorooctanoic acid (PFOA), a persistent and bioaccumulative compound within the broader class of per- and polyfluoroalkyl substances (PFAS), poses a significant challenge to environmental remediation efforts due to its chemical stability and resistance to conventional treatments. This study explores the potential of bacterial strains isolated from a historically petroleum-contaminated site for PFOA biodegradation. Among the three isolates enriched and screened in mineral medium supplemented with 100 mg L⁻¹ PFOA, strain OA1 showed the highest resistance and transformation potential. The selected isolate was identified as Stenotrophomonas acidaminiphila OA1. Batch and fed-batch experiments conducted in enriched medium containing 0.5 mg L⁻¹ PFOA showed no apparent toxicity, with S. acidaminiphila OA1 maintaining stable growth over a 30-day period. PFOA degradation reached 45% under batch conditions, while fed-batch showed lower transformation rates (35%). ¹H NMR spectroscopy suggested the transformation mechanism of PFOA by S. acidaminiphila OA1. This work represents the first report of PFOA biotransformation by Stenotrophomonas acidaminiphila and contributes to the expanding body of knowledge on microbial interactions with perfluorinated compounds. • First report of PFOA biotransformation by Stenotrophomonas acidaminiphila OA1 • No growth inhibition observed in mineral salts medium with 100 mg L⁻¹ PFOA • PFOA removal reached 45% and 32% in batch and fed-batch assays, respectively, over 30 days • ¹H NMR spectrum suggest selective modification of the PFOA backbone