A bright spark: special bacteria in mines, lakes and the human gut pump electrons out and create electricity
- Some bacteria in the most hostile environments pump out electrons and produce electricity
- bacteria in oxygen-free environments have
- Fuel cells and purifying sewage water are some of the potential uses
Some bacteria found in the harshest habitats have been found to pump electrons.
This flow of negatively charged particles is a weak form of electricity.
Researchers at the Massachusetts Institute of Technology (MIT) have discovered that some species of bacteria in oxygen-free environments have evolved their skills.
These low-oxygen habitats include deep mines, the bottom of lakes and even the human gut.
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Some bacteria present in the most rigid habitats have been found to pump electrons. This flow of negatively charged particles is a weak form of electricity
The use of this energy is the ultimate goal for scientists and engineers who are exploring ways to exploit microbial plants.
Fuel cells and purified water are some of the potential uses, say the scientists.
Cells are much smaller than mammalian cells and extremely difficult to grow under laboratory conditions and have posed serious problems for researchers.
MIT engineers have developed a microfluidic technique that can rapidly process small samples of bacteria and measure a specific property that is highly correlated with the bacteria's ability to produce electricity.
This is known as polarizability and can be used to evaluate the electrochemical activity of a bacterium.
"The vision is to choose the strongest candidates to perform the desirable tasks that humans want the cells to do," says Qianru Wang, a postdoc in the MIT Department of Mechanical Engineering.
"There is a recent work suggesting that there could be a much wider range of bacteria that have properties [electricity-producing]," adds Cullen Buie, an associate professor of mechanical engineering at MIT.
"So, an instrument that allows you to probe those organisms could be much more important than we thought, it's not just a small handful of microbes that can do it."
Researchers at the Massachusetts Institute of Technology (MIT) have discovered that some species of bacteria in deprived environments capacity has evolved. These low-oxygen habitats include deep mines, lake beds and even the human gut (stock)
The research was published in the journal Science Advances.
The researcher concluded that the bacteria most electrochemically active bacteria tended to have a higher polarity.
This correlation was observed in all species of bacteria tested by the group.
"We have the necessary tests to see that there is a strong correlation between polarizability and electrochemical activity", says dr. Wang.
"In fact, polarization could be something we could use as a proxy to select high electrochemical activity microorganisms."
HOW DO THE BATTERIES SUPPLIED WITH BACTERIA WORK?
Batteries powered by bacteria could produce a new generation of single-use electronics.
The devices are powered by microbes known as "exoelectrogens", which can transfer electrons to the outside of their cells.
When stratified in a small battery, the bacteria move the electrons through the battery between the two external electrodes.
Bacteria are often freeze-dried to prolong their life and activated by heat or water.