Certain microscopic living things, called ciliates, feed on viruses. It’s an amazing diet, a new study shows.
They are the first living beings, discovered to date, to have the mouth water in the presence of viruses. A study published on December 27, 2022 describes, for the first time, an organism that feeds on viruses. It’s probably not the only one.
It all started with a hypothesis and the research team implemented an experiment to verify it. To do this, they took water from a pond in which they cultivated a rich micro-organic life. Then, they integrated a large quantity of a virus called Chlorella (or chlorovirus) into it. Objective: to observe the evolution of these viral populations according to the evolution of the other living beings present.
Halteria eats chlorovirus
Result: a species of microorganism stood out, a unicellular protozoan named Halteria. This species belongs to the ciliates, small microscopic beings recognizable by the kinds of eyelashes that cover them.
The authors make two very interesting observations:
- Chlorella virus populations were significantly reduced in the presence of Halteria;
- The populations of the microorganism Halteria have inversely… increased, in the presence of Chlorella.
In addition to other evidence that demonstrates their connection, the decline of the chlorovirus accompanies the growth of ciliates in proportions that correspond to what is known in the food chain of the microscopic world. This means that not only does this living being feed on this virus, but that it also uses it as “fuel” to live and multiply. It would even seem that their entire diet is based on it. Infectious for some organisms, these viruses are nutritious for others.
The research team estimates that on the scale of the pond studied, the ciliated microorganisms consume 10 trillion viruses… per day.
Viruses can be nutritious… for some organisms
But where does the “nutrition” aspect come from? What exactly does the Halteria consume when feeding on Chlorella? In addition to carbon, viruses are made up of very good things: nucleic acids, lots of nitrogen and phosphorus “, explains John DeLong, in commenting this study that he piloted. Many living beings eat what passes under their noses, he adds. In doing so, it is not surprising that an organism has learned to feed on these raw materials. And Halteria is not alone in the world on this diet. DeLong and his team have identified other microorganisms, also ciliates, that feed on viruses.
This is just the beginning. The scientists behind this study will now seek to understand the impact of this food web on ecosystems and on the carbon cycle; and also what is their capacity for resilience (in the face of extinctions). ” If this happens on the scale we think possible, it could completely change our view of the global carbon cycle. suggests DeLong.
