A Highly-ordered and Fail-safe Electrical Network in Cable Bacteria

Cable Bacteria are an emerging class of electroactive organisms that sustain unprecedented long-range electron transport across centimeter-scale distances. The pathways of the electrical currents in these filamentous microorganisms remain unresolved. Here, the electrical circuitry in a single cable bacterium is visualized with nanoscopic resolution using Conductive Atomic Force Microscopy. Combined with perturbation experiments, it is demonstrated that electrical currents are conveyed through a parallel network of conductive fibers embedded in the cell envelope which are electrically interconnected between adjacent cells. This redundant structural organization of electrical pathways likely forms a crucial adaptive trait for organisms capable of long-distance electron transport. The observed electrical circuit architecture is unique in biology and could inspire future technological applications in bioelectronics.