Cable bacteria: Live power cables with unprecedented conductivity

Bacteria up to a centimetre long that live on the seabed contain a conductive fibre network that can be compared to the copper cables we use to transport electricity. The highly conductive fibres may lead to revolutionary new materials and technologies. A team of scientists from the University of Antwerp (BE), Delft University of Technology (NL) and Hasselt University (BE) recently discovered this. Cable bacteria are microorganisms that consist of thousands of cells in a row, together more than a centimeter long. Research shows that there are electric currents running through the seabed, and all data indicates that cable bacteria generate and conduct these currents. Within the framework of a new study by the multidisciplinary team of biologists, chemists and physicists, this riddle has now developed a process to isolate a single ‘bacterial wire’ from a seabed sample and attached this microscopic filament (50 times thinner than a human hair) to a homemade arrangement with tiny electrodes. The scientists discovered that the fibers in the cell walls of the bacteria can handle an extremely high electrical current, which is well comparable to the current density in the copper wires of our household appliances. The discovery of the highly conductive fibers in cable bacteria is all the more remarkable because all known biological materials (such as proteins, carbohydrates, lipids or nucleic acids) are very poorly conductive. The scientists involved think they can open the door to numerous possibilities for new materials and technologies. Examples include the development of biodegradable components for electronics and thus reducing the electronic waste problem (‘e-waste’) and/or applications in the medical sector.

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