“This could be very useful for the energy sector,” said Radboud University microbiologist Cornelia Welte SciencealertAhad (17/4/2022).
“In current biogas installations, methane is produced by microorganisms and then burned, which drives a turbine, thereby generating energy. Less than half of the biogas is converted to power and this is the maximum achievable capacity. We wanted to evaluate whether we could do better using microorganisms,” he said.
The focus of their research is kind Archaea, bacteria-like microbes known for their ability to survive under strange and harsh conditions. These microbes are also capable of breaking down methane in oxygen-starved environments.
Microbes known as anaerobic methanotrophic (ANME) archaea, uses this metabolic trick by releasing electrons in a chain of electrochemical reactions.
In 2006, the ANME genus Methanoperedens found to oxidize methane with little help from nitrate. However, Methanoperedens are not suitable microbes for easy cultivation.
So Welte and his fellow researchers collected samples of microbes they knew were dominated by Archaea this methane extractor. The team of scientists then grew them in an oxygen-starved environment where methane was the only electron donor.
Near these microbial colonies, they also placed a metal anode tuned to zero voltage, effectively creating an electrochemical cell ready to generate current.
“We made a kind of battery with two terminals, where one of them is the biological terminal and the other is the chemical terminal,” said microbiologist Helenen Ouboter, also of Radboud University.
“We grew bacteria on one of the electrodes, where the bacteria donated electrons resulting from the conversion of methane,” he said.
After analyzing the conversion of methane to carbon dioxide and measuring the fluctuating currents that spiked as high as 274 milliamperes per square centimeter, the team concluded that more than a third of the currents could be attributed directly to the decomposition of methane.
As far as efficiency goes, 31 percent of the energy in methane has been turned into electric power. This performance makes it somewhat comparable to some power plants.
Scientists now need further exploration to be able to produce batteries highly efficient living using biogas. This is important because some methane power plants barely manage efficiency of around 30 percent.
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