In 2012, a novel type of filamentous sulfur oxidizing bacteria was discovered. These so-called “cable bacteria” occur globally within the upper centimeters of marine and freshwater sediments, and have evolved a unique metabolism, in which electrons are transported from cell-to-cell from one end to the other of their long (> 4 cm) filamentous bodies. This electrical connection enabling long-distance electron transfer (LDET), allows them to conduct two spatially segregated half redox reactions; i.e. harvesting electrons from the electron donor H2S in deeper sediments and channeling the electrons to the electron acceptor O2 that is only present near the sediment surface.
Microbial electron transfer has recently gained considerable attention, as it is fundamental in the development of bioelectrochemical applications for renewable bioenergy and bioremediation of waste. Until now, most attention has been focused on the metal reducing bacteria Shewanella oneidensis and Geobacter sulfurreducens, which are capable of extracellular electron transfer over micrometer distances. Yet large-scale applications of these bioelectrochemical systems are still limited. Due to their capability for long-distance electron transport (LDET; centimeter scale), cable bacteria have emerged as a new and unique opportunity for electromicrobiological research. Recently, cable bacterium filaments have been found attached to the anode of a benthic microbial fuel cell, suggesting they can interact with electrodes and hence may play a potential role in bioelectrochemical systems. Unraveling the electron transfer mechanism of cable bacteria is therefore necessary to see if and how they can be integrated in bioelectrochemical systems, thus forwarding the development of new bioelectrochemical technology.
Filip J. R. Meysman, Rob Cornelissen, Stanislav Trashin, Robin Bonné, Silvia Hidalgo Martinez, Jasper van der Veen, Carsten J. Blom, Cheryl Karman, Ji-Ling Hou, Raghavendran Thiruvallur Eachambadi, Jeanine S. Geelhoed, Karolien De Wael, Hubertus J. E. Beaumont, Bart Cleuren, Roland Valcke, Herre S. J. van der Zant, Henricus T.S. Boschker, Jean V. Manca. A highly conductive fibre network enables centimetre-scale electron transport in multicellular cable bacteria
Open access: http://www.nature.com/ncomms
The multidisciplinary team consists of:
Department Biology, UAntwerp, Belgium (team leader: prof. Filip Meysman)
Departments Fysics and Biology, UHasselt, Diepenbeek, Belgium (team leader: prof. Jean Manca)
Department Chemistry, UAntwerp, Belgium (team leader: prof. Karolien De Wael)
Departments Biotechnology, Bionanoscience and Quantum Nanoscience, TU Delft, Nederland (team leader: prof. Herre van der Zant)
Vlaamse Fonds Wetenschappelijk Onderzoek (FWO), Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO) and European Research Council (ERC).