Removal, bioaccumulation, and metabolization of the fluoroquinolone flumequine by Potamogeton pusillus L.

Water pollution caused by veterinary antibiotics is a growing concern. Phytoremediation, which employs plants to remove emerging contaminants from water, offers a promising solution. This study investigated Potamogeton pusillus L., a submerged macrophyte, for the phytoremediation of flumequine (FLU), a fluoroquinolone commonly used in veterinary medicine, through a 20-day hydroponic experiment. Macrophytes were exposed to 50 and 500 µg L-1 of FLU, and FLU removal, bioaccumulation, metabolite formation, and physiological responses were assessed. Results showed that P. pusillus effectively removed 73 % and 47 % of FLU at 50 and 500 µg L-1, respectively. The highest bioconcentration factors (BCFs) of 476 and 379 L kg⁻¹ d.w. were recorded at day 14. FLU accumulated primarily in roots, followed by leaves and stems. Nine FLU metabolites were tentatively identified, with hydroxylation products (phase I) predominant in roots, while methylation and glucoside conjugation products (phase II) were more abundant in leaves. Minor physiological changes indicated the macrophyte's tolerance. These findings highlight P. pusillus as a promising candidate for FLU phytoremediation.