Nav: Home

Microbial fuel cell converts methane to electricity

May 17, 2017

Transporting methane from gas wellheads to market provides multiple opportunities for this greenhouse gas to leak into the atmosphere. Now, an international team of researchers has taken the first step in converting methane directly to electricity using bacteria, in a way that could be done near the drilling sites.

"Currently, we have to ship methane via pipelines," said Thomas K. Wood, holder of the biotechnology endowed chair and professor of chemical engineering, Penn State. "When you ship methane, you release a greenhouse gas. We can't eliminate all the leakage, but we could cut it in half if we didn't ship it via pipe long distances."

The researchers' goal is to use microbial fuel cells to convert methane into electricity near the wellheads, eliminating long-distance transport. That goal is still far in the future, but they now have created a bacteria-powered fuel cell that can convert the methane into small amounts of electricity.

"People have tried for decades to directly convert methane," said Wood. "But they haven't been able to do it with microbial fuel cells. We've engineered a strain of bacteria that can."

Microbial fuel cells convert chemical energy to electrical energy using microorganisms. They can run on most organic material, including wastewater, acetate and brewing waste. Methane, however, causes some problems for microbial fuel cells because, while there are bacteria that consume methane, they live in the depths of the ocean and are not currently culturable in the laboratory.

"We know of a bacterium that can produce an energy enzyme that grabs methane," said Wood. "We can't grow them in captivity, but we looked at the DNA and found something from the bottom of the Black Sea and synthesized it."

The researchers actually created a consortium of bacteria that produces electricity because each bacterium does its portion of the job. Using synthetic biological approaches, including DNA cloning, the researchers created a bacterium like those in the depths of the Black Sea, but one they can grow in the laboratory. This bacterium uses methane and produces acetate, electrons and the energy enzyme that grabs electrons. The researchers also added a mixture of bacteria found in sludge from an anaerobic digester -- the last step in waste treatment. This sludge contains bacteria that produce compounds that can transport electrons to an electrode, but these bacteria needed to be acclimated to methane to survive in the fuel cell. They report the results of their work today (May 17) in Nature Communications.

"We need electron shuttles in this process," said Wood. "Bacteria in sludge act as those shuttles."

Once electrons reach an electrode, the flow of electrons produces electricity. To increase the amount of electricity produced, the researchers used a naturally occurring bacterial genus -- Geobacter, which consumes the acetate created by the synthetic bacteria that captures methane to produce electrons.

To show that an electron shuttle was necessary, the researchers ran the fuel cell with only the synthetic bacteria and Geobacter. The fuel cell produced no electricity. They added humic acids -- a non-living electron shuttle -- and the fuel cells worked. Bacteria from the sludge are better shuttles than humic acids because they are self-sustaining. The researchers have filed provisional patents on this process.

"This process makes a lot of electricity for a microbial fuel cell," said Wood. "However, at this point that amount is 1,000 times less than the electricity produced by a methanol fuel cell."
-end-
Also working on this project were Michael J. McAnulty, recent doctorate recipient and Venkata Giridhar Poosaria, postdoctoral fellow in chemical engineering; Bruce E. Logan, Evan Pugh Professor in Engineering and the Kappe Professor of Environmental Engineering and Kyoung-Yeol Kim, postdoctoral fellow in the Department of Civil and Environmental Engineering; all at Penn State. Ricardo Jasso-Chávez, National Institute of Cardiology, Mexico City, also participated in this research.

The U.S. Department of Energy's Advanced Research Projects Agency -- Energy supported this work.

Penn State

Related Bacteria Articles:

Bacteria might help other bacteria to tolerate antibiotics better
A new paper by the Dynamical Systems Biology lab at UPF shows that the response by bacteria to antibiotics may depend on other species of bacteria they live with, in such a way that some bacteria may make others more tolerant to antibiotics.
Two-faced bacteria
The gut microbiome, which is a collection of numerous beneficial bacteria species, is key to our overall well-being and good health.
Microcensus in bacteria
Bacillus subtilis can determine proportions of different groups within a mixed population.
Right beneath the skin we all have the same bacteria
In the dermis skin layer, the same bacteria are found across age and gender.
Bacteria must be 'stressed out' to divide
Bacterial cell division is controlled by both enzymatic activity and mechanical forces, which work together to control its timing and location, a new study from EPFL finds.
How bees live with bacteria
More than 90 percent of all bee species are not organized in colonies, but fight their way through life alone.
The bacteria building your baby
Australian researchers have laid to rest a longstanding controversy: is the womb sterile?
Hopping bacteria
Scientists have long known that key models of bacterial movement in real-world conditions are flawed.
Bacteria uses viral weapon against other bacteria
Bacterial cells use both a virus -- traditionally thought to be an enemy -- and a prehistoric viral protein to kill other bacteria that competes with it for food according to an international team of researchers who believe this has potential implications for future infectious disease treatment.
Drug diversity in bacteria
Bacteria produce a cocktail of various bioactive natural products in order to survive in hostile environments with competing (micro)organisms.
More Bacteria News and Bacteria Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Reinvention
Change is hard, but it's also an opportunity to discover and reimagine what you thought you knew. From our economy, to music, to even ourselves–this hour TED speakers explore the power of reinvention. Guests include OK Go lead singer Damian Kulash Jr., former college gymnastics coach Valorie Kondos Field, Stockton Mayor Michael Tubbs, and entrepreneur Nick Hanauer.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Dispatch 6: Strange Times
Covid has disrupted the most basic routines of our days and nights. But in the middle of a conversation about how to fight the virus, we find a place impervious to the stalled plans and frenetic demands of the outside world. It's a very different kind of front line, where urgent work means moving slow, and time is marked out in tiny pre-planned steps. Then, on a walk through the woods, we consider how the tempo of our lives affects our minds and discover how the beats of biology shape our bodies. This episode was produced with help from Molly Webster and Tracie Hunte. Support Radiolab today at Radiolab.org/donate.