Microbial fuel cells bacterial sequences
The long-term performance of microbial fuel cells (MFCs) depends on the microbial communities whose composition strongly influences electron transfer and substrate utilization. The presence of environmental pollutants can cause changes in microbial abundance and biodiversity, and have an effect on the MFC efficacy, however, their long-term operational stability under environmental stress remains insufficiently explored. This study assessed the long-term performance of MFCs using river sediment organic matter as energy, electron, and carbon source during exposure to perfluorooctanoic acid (PFOA). The MFC-PFOA (MFC with PFOA) system operated effectively for 10 months, a maximum voltage of 461.9 mV and a current density peak of 14.5 mA/m², significantly outperforming the control cell. Liquid-chromatography tandem mass spectrometry (LC-MS/MS) analysis confirmed a 94.9 % reduction of PFOA concentration and detected perfluoroheptanoic acid (PFHpA) and perfluorohexanoic acid PFHxA), indicating possible partial transformation and/or redistribution processes within the bioelectrochemical system. Additionally, bacterial community analysis revealed a shift in microbial composition, with Firmicutes and Desulfobacterota becoming dominant, suggesting their roles in the current generation and biotransformation of PFOA. Overall, this work demonstrates long term bioelectricity generation in the presence of per- and polyfluoroalkyl substances (PFAS) pollutants, while indicating partial attenuation and compositional changes of PFOA under bioelectrochemical conditions thus providing valuable insights into the robustness of bioelectrochemical systems for energy recovery in contaminated environments.