Bacterial nanowires

[1][2] Conductive nanowires have also been confirmed in the oxygenic cyanobacterium Synechocystis PCC6803 and a thermophilic, methanogenic coculture consisting of Pelotomaculum thermopropionicum and Methanothermobacter thermoautotrophicus.

[3][4][5] The precise role microbial nanowires play in their biological systems has not been fully realized, but several proposed functions exist.

[3] Outside of a naturally occurring environment, bacterial nanowires have shown potential to be useful in several fields, notably the bioenergy and bioremediation industries.

[6][7] Geobacter nanowires were originally thought to be modified pili, which are used to establish connections to terminal electron acceptors during some types of anaerobic respiration.

[3][13] It wasn't until 1988 that extracellular electron transport (EET) was observed for the first time with the independent discoveries of Geobacter and Shewanella bacteria and their respective nanowires.

[3][14][15] In 1998, EET was observed in a microbial fuel cell setting for the first time using Shewanella bacteria to reduce an Fe(III) electrode.

[3] In microbial fuel cells (MFCs), bacterial nanowires generate electricity via extracellular electron transport to the MFC's anode.

In particular, bacterial nanowires of Geobacter sulfurreducens possess metallic-like conductivity, producing electricity at levels comparable to those of synthetic metallic nanostructures.

[20] When bacterial strains are genetically manipulated to boost nanowire formation, higher electricity yields are generally observed.

[7] With sustainable resources in mind, scientists have proposed the future use of biofilms of Geobacter as a platform for functional under water transistors and supercapacitors, capable of self-renewing energy.