A group of scientists find evidence that some microscopic organisms actively feed on viruses. These organisms are called virovore.
The team of scientists say that although this is the first virovore ever documented, it is likely that many other virovores are still unknown.
In the simplest terms, viruses are very small packets of genetic material. Although they perform many biological functions, such as multiplying themselves, they need to infect and take over other organisms' cell machinery to do so.
This parasitic-like condition has also given rise to a heated and ongoing debate about whether viruses should be considered as living things.
Quoted from Gizmodo, researchers at the University of Nebraska-Lincoln appear to be the first to investigate whether viruses can be considered living things.
Their previous research was very familiar with chlorovirus, a virus abundant in fresh water that infects green algae. They wondered whether certain aquatic organisms relied on viruses as an energy source.
To test this hypothesis, researchers collected pond water samples. Then they transferred as many types of microscopic creatures as they could into the water.
Then, they put large amounts of chlorovirus in the water and let it sit for a day to see if anything changed.
At the end of the experiment, they identified Halteria—a protozoa, a single-celled species that appears to feed on chloroviruses.
Not only did the virus population decrease in the presence of Halteria, but the number of protozoa grew at the same time, indicating that the microbes were using viruses as an energy source.
Halteria also does not grow in the absence of chlorovirus. And when the team used a fluorescent green dye to tag chlorovirus DNA before they entered the water, they could clearly see Halteria's "belly" glow afterward, apparently confirming their viral diet.
It might not be too surprising to learn that some smaller creatures have evolved to ingest viruses on purpose. But as far as the researchers know, their study is the first to show that some microbes can survive on viruses alone.
The findings, published in the journal Proceedings of the National Academy of Sciences, also show that Halteria can feed on chloroviruses as effectively as other microscopic organisms that can feed on small food sources such as bacteria and algae. They estimate Halteria in a small pond could eat as much as 10 trillion chloroviruses a day.
"Viruses contain really good stuff: nucleic acids, lots of nitrogen and phosphorus," said the study's lead author, professor of biological sciences John DeLong.
Team research can have several important implications. These viruses are already known to play an integral role in their freshwater environment, as they recycle carbon and other nutrients, effectively preventing the energy provided from these nutrients from reaching other, larger life forms.
But if living things eat these viruses, which are then eaten by larger organisms and so on, then some of the nutrients and energy that they normally recycle may end up moving up the food chain.
"If this happens on the scale that we think it can happen, it will completely change our view of the global carbon cycle," said DeLong.
DeLong and his team say they have identified another microorganism in the lab that appears to be capable of virovory.