Metatranscriptomes of cable bacteria freshwater enrichments over time

cable bacteria attract associated bacteria during their intense geochemical reengineering of the sediment environment. Cable bacteria oxidize sulfide coupled to oxygen reduction at a physical distance (up to 1 cm). This distance is bridged by their long filamentous appearance and their electron transport capabilities. We supposed that associated bacteria could interact with cable bacteria, using this long-distance electron transport as an alternative electron acceptor in an otherwise electron-acceptor-poor environment (below the oxic and nitrate/nitrite penetration depths) to finish their energy metabolism. This would then happen via interspecies electron transfer, where an associated bacterium uses specific gene sets to reduce cable bacteria, or an intermediary (an electron shuttle) to close their metabolism. Metatranscriptomes were used to determine the transcription of such IET gene sets.