Does pre-enrichment of anodes with acetate to select for Geobacter spp. enhance performance of microbial fuel cells when switched to more complex substrates?

• DOI: 10.3389/fmicb.2023.1199286
• Publication Date: 2023-11-23T12:02:41Z
• Authors: Beate Christgen; Martin Spurr; Edward M. Milner; Paniz Izadi; Clare McCann; Eileen Yu; Tom Curtis; Keith Scott; Ian M. Head
• Keywords: Geobacter

Many factors affect the performance of microbial fuel cells (MFCs). Considerable attention has been given to impact cell configuration and materials on MFC performance. Much less work done anode microbiota, particularly in context using complex substrates as fuel. One strategy improve such wastewater, is pre-enrich with known, efficient electrogens, Geobacter spp. The implication this that electrogens are limiting factor MFCs fed organisms feeding through hydrolysis fermentation not limiting. We conducted a systematic test assumptions associated it. Microbial were enriched three different (acetate, synthetic wastewater real domestic wastewater) inocula (Activated Sludge, Tyne River sediment, effluent from an MFC). Reactors either start or initially acetate enrich for before switching wastewater. Pre-enrichment increased relative abundance switched compared had beginning experiment (wastewater-fed - 21.9 ± 1.7% spp.; acetate-enriched MFCs, 34.9 6.7% Synthetic – 42.5 3.7% wastewater-fed 47.3 3.9% spp.). However, pre-enrichment did translate into significant improvements voltage, maximum current density, power density substrate removal efficiency. Nevertheless, coulombic efficiency (CE) was higher pre-enriched when following enrichment CE = 22.0 6.2%; =58.5 3.5%; 3.2%; 28.7 4.2%.) ssp. represents average nine replicate reactors inoculated each substrate. Efforts anodic communities utilizing organic should therefore focus enhancing activity driving rather terminal-oxidizing electrogens.