Deep within your belly, right now, there are thousands of bacteria flickering away with electricity.
Scientists from the UC Berkeley in Northern California have recently been studying hundreds of bacterial species that are capable of “sparking” tiny electrical currents, many of which live peacefully within the human gut microbiome.
Electrogenic bacteria – bacteria that can generate electricity – are usually associated with extreme low-oxygen environments, like the bottom of lakes or in the depths of an acidic mine. While they can be found in many different places across our planet, scientists were pretty surprised to find they were so prolific in the human gut.
“The fact that so many bugs that interact with humans, either as pathogens or in probiotics or in our microbiota or involved in fermentation of human products, are electrogenic — that had been missed before,” Dan Portnoy, a UC Berkeley professor of molecular and cell biology, and of plant and microbial biology, said in a statement.
“It could tell us a lot about how these bacteria infect us or help us have a healthy gut.”
As reported in the journal Nature, some of the species capable of this included Listeria, a pathogenic bacteria that are most often associated with food poisoning, the bacteria that cause gangrene, and Lactobacilli, the bacteria that are important in fermenting yogurt.
The bacteria can stream a current of up to 500 microamps. Granted, that’s not enough to charge your phone, but the researcher believes their discovery could be used to developed so-called “living batteries” microbes or even bioenergetic batteries to produce electricity from water treatment plants.
You’re probably wondering, what business do bacteria have making electricity?
Well, they do it for the same reason we breathe oxygen, to remove electrons produced during metabolism and support energy production. Bacteria that live in an environment with low oxygen often use a mineral, like iron or manganese, as an electron acceptor. This process, however, requires numerous chemical reactions to take place. One of these is a bioelectrochemical process where electrons are transferred from the inside of the cell to the outside.
In short, they “breathe” metals and produce a tiny electrical current as a by-product.
“It seems that the cell structure of these bacteria and the vitamin-rich ecological niche that they occupy makes it significantly easier and more cost effective to transfer electrons out of the cell,” said first author Sam Light, a postdoctoral fellow. “Thus, we think that the conventionally studied mineral-respiring bacteria are using extracellular electron transfer because it is crucial for survival, whereas these newly identified bacteria are using it because it is ‘easy.’”