The discovery, by researchers at the University of Massachusetts Amherst, may one day make into an electronic device or medgadget of your own. The scientists discovered “nanowires” 3-5 nanometers in width produced by Geobacter bacterium that the organism probably uses “to transfer electrons outside the cell onto insoluble electron acceptors, such as iron minerals and possibly electrodes.”
The findings of microbiologist Derek R. Lovley’s research team are published in the June 23rd issue of Nature, an international science journal. Researchers found that the conductive structures, known as “microbial nanowires,” are produced by a novel microorganism known as 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.
“Such long, thin conductive structures are unprecedented in biology,” said Lovley. “This completely changes our concept of how microorganisms can handle electrons, and it also seems likely that microbial nanowires could be useful materials for the development of extremely small electronic devices.”
“The microbial world never stops surprising us,” said Dr. Aristides Patrinos of the U.S. Department of Energy, which funds the Geobacter research. “The remarkable and unexpected discovery of microbial structures comprising microbial nanowires that may enable a microbial community in a contaminated waste site to form mini-power grids could provide new approaches to using microbes to assist in the remediation of DOE waste sites; to support the operation of mini-environmental sensors, and to nano-manufacture in novel biological ways. This discovery also illustrates the continuing relevance of the physical sciences to today’s biological investigations.”
Eugene Madsen, a Cornell University research microbiologist, noted, “I have watched and judged, in peer review, many of Dr. Lovley’s remarkable scientific advancements since the discovery of Geobacter in 1987. The latest advancement, microbial nanowires, is another major milestone because it may usher in a new era of exploration of both microbial respiration and bio-electronics.” The findings, he said, are “promising and exciting,” although he emphasized the information must be independently confirmed and extended by other microbiologists and biophysicists…
Ultrafine wires, often referred to as nanowires, are required for further miniaturization of electronic devices. Manufacturing nanowires from more traditional materials such as metals, silica, or carbon is difficult and expensive. However, it is easy to grow billions of Geobacter cells in the laboratory and harvest the microbial nanowires that they produce. Furthermore, by altering the DNA sequence of the genes that encode for microbial nanowires, it may be possible to produce nanowires with different properties and functions.
Another interesting implication of this research is that it suggests a mechanism for microbes to share energy in a mini-power grid. The nanowire pili of individual Geobacter often intertwine, suggesting a strategy by which Geobacter might share electricity…