Microbially-Produced Electrical Wires

Filed in archive Other Biotechnology News on July 8, 2005

My first foray into microbiological research threw me into the world of iron-reducing bacteria, a field pioneered by Derek Lovley who has been working on this group of anaerobic bugs, and who in 1987, discovered Geobacter. Ten years hence, I am still working on them, albeit for a different research group, and apparently, so is he. In the June 23rd issue of Nature , Dr. Lovley and his research group reports findings that conductive structures, known as "microbial nanowires," are produced by Geobacter . The nanowires are incredibly fine, only 3-5 nanometers in width (20,000 times finer than a human hair), but quite durable and more than a thousand times long as they are wide.

Geobacter can live in the absence of oxygen because of its ability to transfer electrons outside the cell onto iron minerals, which are natural constituents of most soils. However, prior to the discovery of its conductive pili it was unknown how this electron transfer might take place.

The discovery of these conductive pili may have potential applications in the electronics industry, particularly in the miniaturisation of electronic devices, where ultra-fine wires, called nanowires are used. Geobacter may be a viable and less expensive alternative to more traditional materials such as metals, silica, or carbon.