This study assessed cell voltage development, electricity recovery, and microbial community composition in response to initial substrate including acetate, xylose, acetate/xylose 1:1 mixture (ace/xyl), and bioethanol effluent (BE)during microbial fuel cell (MFC) operation at 1000Ω external resistance. The BE mainly contained 20.5 g/L xylose, 1.8 g/Larabinose, and 2.5 g/L propionic acid. The MFCs initially fedwith acetate showed shorter initiation time (1 day), higheraverage cell voltage (634±9 mV), and higher coulombic efficiency(31.5±0.5 %) than those initially fed with ace/xyl orxylose. However, BE-initiated MFCs only generated 162±1 mV. The acetate-initiated MFCs exhibited longer adaptation time (21 h) and lower cell voltage (645±10 mV) when the substrate was switched to xylose, whereas substrate switching to BE produced the highest voltage (656 mV), maximumpower density (362±27 mW/m2), maximum current density (709±27 mA/m2), and coulombic efficiency (25±0.5 %) in the acetate-initiated MFCs. The microbial community inacetate-initiated MFCs was less diverse and contained more electrogenic bacteria (13.9±0.4 %) including Geobactersulfurreducens and Desulfuromonas acetexigen than theMFCs initially fed with ace/xyl, xylose, and BE. After switching the substrate to xylose and subsequently to BE,the microbial community in the acetate-initiated MFCs became more diverse, while no significant changes were observed in ace/xyl-, xylose-, and BE-initiated MFCs. The results showed that initial substrate affected the power generation and the capability to adapt to the substrate alteration in MFCs. Acetate-initiated MFCs showed best performance inutilizing BE.
- Microbial fuel cell
- Bioethanol effluent
- Denaturing gradient gel electrophoresis
- Coulombic efficiency