Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Live wires

11.07.2006
A microbiologist discovers our planet is hard-wired with electricity-producing bacteria

When Yuri Gorby discovered that a microbe which transforms toxic metals can sprout tiny electrically conductive wires from its cell membrane, he reasoned this anatomical oddity and its metal-changing physiology must be related.

A colleague who had heard Gorby's presentation at a scientific meeting later reported that he, too, was able to coax nanowires from another so-called metal-reducing bacteria species and futher suggested the wires, called pili, could be used to bioengineer electrical devices.

It now turns out that not only are the wires and their ability to alter metal connected--but that many other bacteria, including species involved in fermentation and photosynthesis, can also form wires under a variety of environmental conditions.

"Earth appears to be hard-wired," said Gorby, staff scientist at the Department of Energy's Pacific Northwest National Laboratory, who documents the seeming ubiquity of electrically conductive microbial life in the July 10 advance online Proceedings of the National Academy of Science.

In a series of experiments, Gorby and colleagues induced nanowires in a variety of bacteria and demonstrated that they were electrically conductive. The bacterial nanowires were as small as 10 nanometers in diameter and formed bundles as wide as 150 nanometers. They grew to be tens of microns to hundreds of microns long.

The common thread involved depriving a microbe of something it needed to shed excess energy in the form of electrons. For example, Shewanella, of interest in environmental cleanup for its ability to hasten the weathering of toxic metals into benign ones, requires oxygen or other electron acceptors for respiration, whereas Synechocystis, a cyanobactetrium, combines electrons with carbon dioxide during photosynthesis.

Bereft of these "electron acceptors," bacterial nanowires "will literally reach out and connect cells from one to another to form an electrically integrated community," Gorby said.

"The physiological and ecological implications for these interactions are not currently known," he said, "but the effect is suggestive of a highly organized form of energy distribution among members of the oldest and most sustainable life forms on the planet."

In one clever twist, Gorby grew pili from mutant strains developed by collaborators that were unable to produce select electron transport components called cytochromes. Sure enough, the nanowires of the mutants were poor conductors.

"These implicate cytochromes as the electrically conductive components of nanowires, although this has yet to be conclusively demonstrated," Gorby said.

To measure currents as precisely as possible, Gorby and colleagues from the University of Southern California have built a microbial fuel cell laboratory at PNNL. The small bacteria-powered batteries, cultured under electron-acceptor limitations and fueled by lactate or light, now produce very little power, as measured by a voltmeter hooked to a laptop computer.

Co-author and PNNL scientist Jeff Mclean, who manages the microbial fuel cell laboratory, said that small changes in fuel cell design and culture conditions have already shown large improvements in the efficiency of the fuel cells. For example, so-called biofilms--a highly interconnected bacterial community--put out much more energy than other configurations.

Bill Cannon | EurekAlert!
Further information:
http://www.pnl.gov

More articles from Life Sciences:

nachricht Transport of molecular motors into cilia
28.03.2017 | Aarhus University

nachricht Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Researchers shoot for success with simulations of laser pulse-material interactions

29.03.2017 | Materials Sciences

Igniting a solar flare in the corona with lower-atmosphere kindling

29.03.2017 | Physics and Astronomy

As sea level rises, much of Honolulu and Waikiki vulnerable to groundwater inundation

29.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>