Bacteria producing nanowires made up of cytochrome OmcS. Credit: Ella Maru Studio
Cooling Speeds Up Electrons in Bacterial Nanowires
The ground underneath our feet and under the ocean flooring is an electrically-charged grid produced by germs “breathing out” excess electrons through tiny nanowires in an oxygen-depleted environment. By identifying the mechanism of electron flow, Yale University researchers have been studying ways to enhance this natural electrical conductivity within nanowires 1/100,000 th the width of a human hair.
In a new research study released today (May 11, 2022) in Science Advances, a team led by graduate student Peter Dahl with Nikhil Malvankar, Assistant Professor of Molecular Biophysics and Biochemistry in the Microbial Sciences Institute, and Victor Batista, Professor of Chemistry, found that nanowires move 10 billion electrons per second with no energy loss. This research study explains the remarkable capability of these bacteria to send electrons over fars away.
The scientists also found that cooling the environment around the nanowires of the germs Geobacter from space temperature level to freezing increases conductivity 300-fold. This is extremely unexpected since cooling typically freezes electrons and slows them down in organic materials. By integrating experiments with theory, the scientists discovered that colder temperature levels restructure hydrogen bonds and flatten heme proteins within nanowires, hence enhancing the flow of electrical power.
Leveraging this naturally taking place electrical grid might one day result in the advancement of living and self-repairing electrical circuits, new sources of electrical energy, and bioremediation methods.
Reference: “300-fold conductivity boost in microbial cytochrome nanowires due to temperature-induced restructuring of hydrogen bonding networks” 11 May 2022, Science Advances.DOI: 10.1126/ sciadv.abm7193.
Other authors consist of Sophia Yi, Yangqi Gu, Catharine Shipps, Jens Neu, Patrick OBrien, Dennis Vu and Sibel Ebru Yalcin from the Malvankar Lab, and Atanu Acharya, Uriel Morzan, and Subhajyoti Chaudhuri from the Batista Lab.
