Magnet anode enhances extracellular electron transfer and enrichment of exoelectrogenic bacteria in bioelectrochemical systems.

The constructed magnetic MFCs obtained better performance compared with the non-magnetic MFC, in terms of voltage production, power density, and coulombic efficiency. The relative abundance of Geobacter spp. (one kind of exoelectrogen) was much higher in the magnetic MFCs. The optimal static magnetic field intensity for enriching exoelectrogens is around 80 mT. It is likely that the decrease of internal resistance, enrichment in exoelectrogens, and the syntrophic interactions between exoelectrogens and methanogens result in the enhanced performance of magnetic MFCs. This study provides a magnetic method for the enrichment of exoelectrogens, which can be extensively applied in bioelectrochemical systems.