Featured Research

from universities, journals, and other organizations

New Microbe Strain Makes More Electricity, Faster

Date:
August 3, 2009
Source:
University of Massachusetts Amherst
Summary:
In their most recent experiments with Geobacter, the sediment-loving microbe whose hairlike filaments help it to produce electric current from mud and wastewater, scientists supervised the evolution of a new strain that dramatically increases power output per cell and overall bulk power. It also works with a thinner biofilm than earlier strains, cutting the time to reach electricity-producing concentrations on the electrode.

Dr. Hana Yi takes a reading from fuel cells.
Credit: Image courtesy of University of Massachusetts Amherst

In their most recent experiments with Geobacter, the sediment-loving microbe whose hairlike filaments help it to produce electric current from mud and wastewater, Derek Lovley and colleagues at the University of Massachusetts Amherst supervised the evolution of a new strain that dramatically increases power output per cell and overall bulk power. It also works with a thinner biofilm than earlier strains, cutting the time to reach electricity-producing concentrations on the electrode.

“This new study shows that output can be boosted and it gives us good insights into what it will take to genetically select a higher-power organism.” The work, supported by the Office of Naval Research and the U.S. Department of Energy, is described in the August issue of the journal, Biosensors and Bioelectronics, now available online.

Findings open the door to improved microbial fuel cell architecture and should lead to “new applications that extend well beyond extracting electricity from mud,” Lovley says. In the new experiments, the UMass Amherst researchers adapted the microbe’s environment, which pushed it to adapt more efficient electric current transfer methods.

“In very short order we increased the power output by eight-fold, as a conservative estimate,” says Lovley. “With this, we’ve broken through the plateau in power production that’s been holding us back in recent years.” Now, planning can move forward to design microbial fuel cells that convert waste water and renewable biomass to electricity, treat a single home’s waste while producing localized power (especially attractive in developing countries), power mobile electronics, vehicles and implanted medical devices, and drive bioremediation of contaminated environments.

Geobacter’s hairlike pili are extremely fine, only 3 to 5 nanometers in diameter or about 20,000 times finer than a human hair, and more than a thousand times longer than they are wide. Nevertheless, they are strong. Nicknamed nanowires for their role in moving electrons, pili are the secret to this particular microbe’s ability to produce electric current from organic waste and sediment. Geobacter’s pili seem critical for forming the biofilm which aids transfer of the electron products to iron in soil and sediment. In nature, bacteria colonies form gluey biofilms to anchor to a surface such as a tooth or an underwater rock, providing a living environment near a food source.

The Geobacter biofilm’s “fortuitous” electron-transferring skill, the product of natural selection, suggested a pathway to Lovley―a way he might use selective pressure to increase its capacity to produce power. He and colleagues grew Geobacter as usual on a graphite electrode, providing acetate as food and allowing a colony to form the biologically active slime, or biofilm where electron transfer takes place across the nanowires. But for this new experiment they added a tiny, 400-millivolt “pushback” current in the electrode that forced Geobacter to press harder to get rid of its electrons.

The result of providing a more challenging environment, within five short months, Lovley notes, was evolution of a beefed-up microorganism that can press at least eight times more electric current across the electrode than the original strain. “I’m really happy with this outcome,” the microbiologist notes. “It’s exceptionally fast feedback to us and a very satisfying result.” He adds, “I’m still a little amazed that they make electricity, but I’m happy to be exploring how to harness that ability. I’m sure there’ll be applications developed in the future that we can’t even envision right now.”

Lovley’s first experiments with the anaerobic microbe, Geobacter, which he and colleagues discovered in sediment under the Potomac River in 1987, explored its use in decontaminating soil due to its ability to respire iron and other metals the way we breathe oxygen. Geobacter showed promise for a variety of bioremediation tasks, but the microbiologists further discovered in 2002 that it could produce electricity from the organic matter found in soils, sediments and wastewater. This ability appeared to be a feature of the electrically conductive pili, discovered in 2005. Together, these discoveries have led to intense research on how to harness the microbes for producing electricity in microbial fuel cells.

Microbial fuel cells, which convert fuel to electricity without combustion, consist of an electrode known as an anode that accepts electrons from the microorganisms, and another electrode known as a cathode, which transfers electrons onto oxygen. Electrons flow between the anode and the cathode to provide the current that can be harvested to power electronic devices.


Story Source:

The above story is based on materials provided by University of Massachusetts Amherst. Note: Materials may be edited for content and length.


Cite This Page:

University of Massachusetts Amherst. "New Microbe Strain Makes More Electricity, Faster." ScienceDaily. ScienceDaily, 3 August 2009. <www.sciencedaily.com/releases/2009/07/090729210821.htm>.
University of Massachusetts Amherst. (2009, August 3). New Microbe Strain Makes More Electricity, Faster. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2009/07/090729210821.htm
University of Massachusetts Amherst. "New Microbe Strain Makes More Electricity, Faster." ScienceDaily. www.sciencedaily.com/releases/2009/07/090729210821.htm (accessed October 21, 2014).

Share This



More Matter & Energy News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Gulfstream G500, G600 Unveiling

Gulfstream G500, G600 Unveiling

Flying (Oct. 20, 2014) Watch Gulfstream's public launch of the G500 and G600 at their headquarters in Savannah, Ga., along with a surprise unveiling of the G500, which taxied up under its own power. Video provided by Flying
Powered by NewsLook.com
Japanese Scientists Unveil Floating 3D Projection

Japanese Scientists Unveil Floating 3D Projection

Reuters - Innovations Video Online (Oct. 20, 2014) Scientists in Tokyo have demonstrated what they say is the world's first 3D projection that floats in mid air. A laser that fires a pulse up to a thousand times a second superheats molecules in the air, creating a spark which can be guided to certain points in the air to shape what the human eye perceives as an image. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

3BL Media (Oct. 20, 2014) Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-fuel Impala Video provided by 3BL
Powered by NewsLook.com
What We Know About Microsoft's Rumored Smartwatch

What We Know About Microsoft's Rumored Smartwatch

Newsy (Oct. 20, 2014) Microsoft will reportedly release a smartwatch that works across different mobile platforms, has a two-day battery life and tracks heart rate. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins