by Keyword: Cables

Pankratov, Dmitrii, Martinez, Silvia Hidalgo, Karman, Cheryl, Gerzhik, Anastasia, Gomila, Gabriel, Trashin, Stanislav, Boschker, Henricus T S, Geelhoed, Jeanine S, Mayer, Dirk, De Wael, Karolien, Meysman, Filip J R, (2024). The organo-metal-like nature of long-range conduction in cable bacteria Bioelectrochemistry 157, 108675

Cable bacteria are filamentous, multicellular microorganisms that display an exceptional form of biological electron transport across centimeter-scale distances. Currents are guided through a network of nickel-containing protein fibers within the cell envelope. Still, the mechanism of long-range conduction remains unresolved. Here, we characterize the conductance of the fiber network under dry and wet, physiologically relevant, conditions. Our data reveal that the fiber conductivity is high (median value: 27 S cm-1; range: 2 to 564 S cm-1), does not show any redox signature, has a low thermal activation energy (Ea = 69 +/- 23 meV), and is not affected by humidity or the presence of ions. These features set the nickel-based conduction mechanism in cable bacteria apart from other known forms of biological electron transport. As such, conduction resembles that of an organic semi-metal with a high charge carrier density. Our observation that biochemistry can synthesize an organometal-like structure opens the way for novel bio-based electronic technologies.

JTD Keywords: 'current, Activation energy, Bacteria, Bioelectronic, Bioelectronics, Cable bacteria, Cable bacteria, long -distance electron transport, protein conductivity, electrochemical impedance spectroscopy, bioelectronic, Cables, Centimeter-scale, Electrochemical impedance spectroscopy, Electrochemical-impedance spectroscopies, Electron transport, Electron transport properties, Electron-transport, microbial nanowires, proteins, sulfu, Long-distance electron transport, Nickel, Nickel containing, Protein conductivity, Protein fibers, Proteins