Surpreendente descoberta de nanofios bacterianos pode levar a circuitos elétricos vivos e auto-reparáveis

Bactérias produtoras de nanofios compostos de citocromo OmcS. Crédito: Estúdio Ella Maru

Resfriamento acelera elétrons em nanofios bacterianos

O solo sob nossos pés e sob o fundo do oceano é uma grade eletricamente carregada criada por bactérias “exalando” excesso de elétrons através de minúsculos nanofios em um ambiente com pouco oxigênio. Ao identificar o mecanismo do fluxo de elétrons,[{” attribute=””>Yale University researchers have been studying ways to improve this natural electrical conductivity within nanowires 1/100,000th the width of a human hair.

In a new study published 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 without any energy loss. This research explains the remarkable capacity of these bacteria to send electrons over long distances.

The researchers also found that cooling the environment around the nanowires of the bacteria Geobacter from room temperature to freezing increases conductivity 300-fold. This is very surprising because cooling typically freezes electrons and slows them down in organic materials. By combining experiments with theory, the researchers found that colder temperatures restructure hydrogen bonds and flatten heme proteins within nanowires, thus enhancing the flow of electricity.

Leveraging this naturally occurring electrical grid might one day lead to the development of living and self-repairing electrical circuits, new sources of electricity, and bioremediation strategies.  

Reference: “300-fold conductivity increase 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 include Sophia Yi, Yangqi Gu, Catharine Shipps, Jens Neu, Patrick O’Brien, Dennis Vu and Sibel Ebru Yalcin from the Malvankar Lab, and Atanu Acharya, Uriel Morzan, and Subhajyoti Chaudhuri from the Batista Lab.