Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Microbe Strain Makes More Electricity, Faster

30.07.2009
Researchers have coaxed Geobacter, the sediment-loving microbe who produce electric current from mud and wastewater, to evolve a new strain. It dramatically increases power output per cell, overall bulk power, and with a thinner biofilm, cuts the time to produce electricity on the electrode.

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.

Several high-resolution photographs are available for this story at: http://www.geobacter.org/publications/19487117/

Derek Lovley | Newswise Science News
Further information:
http://www.umass.edu

More articles from Power and Electrical Engineering:

nachricht Supersonic waves may help electronics beat the heat
18.05.2018 | DOE/Oak Ridge National Laboratory

nachricht Researchers control the properties of graphene transistors using pressure
17.05.2018 | Columbia University

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Research reveals how order first appears in liquid crystals

23.05.2018 | Life Sciences

Space-like gravity weakens biochemical signals in muscle formation

23.05.2018 | Life Sciences

NIST puts the optical microscope under the microscope to achieve atomic accuracy

23.05.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>