The Geobacter sulfurreducens bacteria conduct current through ordered fibers made of an unexpected protein, found the team at the University of Virginia School of Medicine. These proteins surround a core of metal-containing molecules, creating nanowires.
Geobacter bacteria play important roles in the soil, including facilitating mineral turnover and even cleaning up radioactive waste. They survive in environments without oxygen, and they use nanowires to rid themselves of excess electrons. These could be used to harness the power of bioenergy to cleaning up pollution to creating biological sensors. It could actually serve as the bridge between electronics and living cells.
"There are all sorts of implanted medical devices that are connected to tissue, like pacemakers with wires, and this could lead to applications where you have miniature devices that are actually connected by these protein filaments," said Dr Edward Egelman at UVA. "We can now imagine the miniaturization of many electronic devices generated by bacteria, which is pretty amazing."
"The technology [to understand nanowires] didn't exist until about five years ago, when advances in cryo-electron microscopy allowed high resolution," said Egelman, of UVA's Department of Biochemistry and Molecular Genetics. "We have one of these instruments here at UVA, and, therefore, the ability to actually understand at the atomic level the structure of these filaments. ... So this is just one of the many mysteries that we've now been able to solve using this technology, like the virus that can survive in boiling acid, and there will be others."