The driving role of extracellular polymeric substances in the bioelectrical conversion of petroleum hydrocarbons by rhizosphere microbial fuel cells: bioelectricity production, substrate bioconversion, microbial function and their network correlation

作者：Lanmei Zhao, Yuru Wen, Lyu Can, Long Meng, Jian Liu, Dong Zhao · 发表于：Bioresources and Bioprocessing · 年份：2025 · DOI：10.1186/s40643-025-00922-4 · 被引用次数：4 · 研究领域：Microbial Fuel Cells and Bioremediation、Electrochemical sensors and biosensors、Wastewater Treatment and Nitrogen Removal

Abstract Extracellular polymeric substances (EPS), are crucial components of biofilms that drive the bioelectrical conversion of petroleum hydrocarbons (PHCs), but their role has not been adequately addressed. This research explores the driving role of EPS in bioelectrical PHC conversion by rhizosphere microbial fuel cells (MFCs). We found that current density, output voltage, coulombic efficiency, power density, current stabilization time, metabolite volatile fatty acid (VFA) production and PHC biodegradation ratio initially increased and then decreased with rising initial EPS level (0-128 mg·g − 1 ), peaking at 64 ± 1 mA·m − 2 , 8.04 ± 0.16 V, 60.9 ± 1.2%, 129 ± 3 mW·m − 2 , 23 ± 1 days, 1.77 ± 0.04 g·kg − 1 and 66.7 ± 1.5%, respectively. Fluorescence intensity of proteins having tyrosine-tryptophan demonstrated a continuous enhancement, consistent with increased biofilm thickness. Within an appropriate range of initial EPS levels (0–64 mg·g⁻¹), bioelectricity generation and PHC bioconversion enhanced as the EPS content rose in mature biofilms. However, excessive EPS addition could increase biofilm thickness to 0.48 mm, which in turn reduced biofilm activity and overall system performance. The abundances of electrochemically active and PHC-degrading bacteria presented an initial increase followed by a subsequent decrease as the initial EPS level rose, highlighting that EPS at the optimal level enriched and activated these functional bacteria. The positive correlations betwe...