Some bacteria that exist in the harshest of habitats have been found to pump out electrons.
This stream of negatively charged particles is a weak form of electricity.
Researchers at the Massachusetts Institute of Technology (MIT) found certain species of bacteria in oxygen-deprived environments have evolved the ability.
These low-oxygen habitats include deep within mines, at the bottom of lakes, and even in the human gut.
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Some bacteria that exist in the harshest of habitats have been found to pump out electrons. This stream of negatively charged particles is a weak form of electricity
Harnessing this energy is the end goal for scientists and engineers who are exploring ways to harness the microbial power plants.
Fuel cells and purifying sewage water are some of the potential uses, scientists claim.
The cells are much smaller than mammalian cells and extremely difficult to grow in laboratory conditions and posed severe problems for the researchers.
MIT engineers developed a microfluidic technique that can quickly process small samples of bacteria and gauge a specific property that’s highly correlated with bacteria’s ability to produce electricity.
This is known as polarisability and can be used to assess a bacteria’s electrochemical activity.
‘The vision is to pick out those strongest candidates to do the desirable tasks that humans want the cells to do,’ says Qianru Wang, a postdoc in MIT’s Department of Mechanical Engineering.
‘There is recent work suggesting there might be a much broader range of bacteria that have [electricity-producing] properties,’ adds Cullen Buie, associate professor of mechanical engineering at MIT.
‘Thus, a tool 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 this.’
Researchers at the Massachusetts Institute of Technology (MIT) found certain species of bacteria in oxygen-deprived environments have evolved the ability. These low-oxygen habitats include deep within mines, at the bottom of lakes, and even in the human gut (stock)
The research has been published in the journal Science Advances.
Researcher concluded that bacteria that more electrochemically active bacteria tended to have a higher polarisability.
This correlation was observed across all species of bacteria that the group tested.
‘We have the necessary evidence to see that there’s a strong correlation between polarisability and electrochemical activity,’ Dr Wang says.
‘In fact, polarisability might be something we could use as a proxy to select microorganisms with high electrochemical activity.’
HOW DO BACTERIA-POWERED BATTERIES WORK?
Batteries powered by bacteria could produce a new generation of disposable electronics.
The devices are fuelled by microbes known as ‘exoelectrogens’, which can transfer electrons outside of their cells.
When layered into a small battery, the bacteria shift electrons across the battery between its two external electrodes.
The bacteria are often freeze-dried to extend their shelf-life and activated by heat or water.