Synergistic effects of organic matter degrading and electroactive biofilms for rapid startup of sediment microbial fuel cells: From laboratory scale to in situ application

Sediment microbial fuel cells (SMFCs) have been developed as sensors and reactors to remediate polluted environment and facilitate online monitoring. However, their industrial feasibility is hampered by long startup times. In this paper, we demonstrated that SMFCs could be rapidly initiated by employing precultured anodes. The performance of precultured anodes in reducing startup times was strongly influenced by the duration of culture time. High-throughput sequencing techniques and community level physiological profiling (CLPP) methods were utilized to study the structural and functional diversity of the bacterial communities on incubated anodes. Results revealed that the collaborative role of organic matter degrading biofilms and electroactive biofilms on the anodes in expediting startup. Network interactions analysis further showed more compact co-occurrence patterns, less topological roles of individual Operational Taxonomic Units (OTUs) and dominant modules were obtained after SMFCs setup. This was primarily due to the formation of more stable and higher microbial carbon metabolism functions anode biofilms. An optimal biomass level of 2000 μg protein cm −2 on the anode was typically achieved seven days after SMFCs initiation. Based on the results of laboratory experiments, the optimal start-up strategy was obtained, and successfully applied to the starting of in-situ on-line monitoring sensors. This study could realize the potential of SMFCs for large-scale field applications. • SMFCs could be rapidly initiated by employing pre-cultured anodes. • The performance of pre-cultured anodes was strongly influenced by the duration of culture time. • Organic matter degrading and electroactive biofilms played the collaborative role in expediting startup. • Microbial carbon metabolism functions were closely related to the startup of SMFCs; • A optimal start-up strategy was successfully applied to a in-situ sensor.