Hydrated cable bacteria exhibit protonic conductivity over long distances.

This study presents the direct measurement of proton transport along filamentous , or cable bacteria. Cable bacteria are filamentous multicellular microorganisms that have garnered much interest due to their ability to serve as electrical conduits, transferring electrons over several millimeters. Our results indicate that cable bacteria can also function as protonic conduits because they contain proton wires that transport protons at distances >100 µm.