The virus, an organism that is ‘neither alive nor dead’ and whose sole purpose is to make as many copies of itself as possible, could serve some organisms as food. While it is a virus – specifically, the SARS-CoV-2 coronavirus – that is causing humans serious public health and socio-economic problems through the global COVID-19 pandemic, other living beings probably know how to get a much more profitable performance of this type of infectious agent.
At least, this is the conclusion reached by a group of scientists, who have shown that two groups of little-known marine protists ingest viruses on a regular basis. In biology, we know the organisms of the Protista Kingdom – they are neither fungi, nor animals, nor flat – as beings that can be unicellular or multicellular and that include organisms such as algae, protozoa (microscopic) and molds.
The new discovery suggests that viruses serve these food organisms, probably as a way to absorb phosphorus and nitrogen.
This is the first convincing evidence , -according to the study, published in Frontiers in Microbiology- , of organisms that use viruses for nutrition, despite the fact that these infectious agents live in huge numbers in all corners of the Earth, from the atmosphere to the deepest ocean.
The article concludes that two groups of ecologically important marine protists, the coanozoa and picozoa, are virus eaters and capture their ‘prey’ through phagocytosis – that is, by engulfing them.
Method
And how have scientists found out about this? As described on the Frontiers Science News website, Stepanauskas’s team (lead author) took samples of sea surface water from two areas of the planet: the Northwest Atlantic, in the Gulf of Maine, in July 2009; and in the Mediterranean in front of Catalonia; in January and July 2016.
After collecting samples, they used modern single-cell genomics tools to sequence the DNA of 1,698 protists. They collected a variety of protists: alveolates, stramenopiles, chlorophytes, cercozoa, picozoa, and choanozoa. As well; the analysis of choanozoa and picozoa was associated with viral sequences of bacteriophages and viruses.
Although the objective of virus phagocytosis has yet to be confirmed, the authors already have a hypothesis that they consider probable: ” Viruses are rich in phosphorus and nitrogen, and could be a good complement to a diet rich in carbon .”
Future research will be able to determine whether virus-consuming protists accumulate DNA sequences from their viral prey within their own genomes, or consider how these organisms might protect themselves from infection.
Referencias:
Julia M. Brown, Jessica M. Labonté, Joseph Brown, Nicholas R. Record, Nicole J. Poulton, Michael E. Sieracki, Ramiro Logares and Ramunas Stepanauska. ‘Single Cell Genomics Reveals Viruses Consumed by Marine Protists’. Front. Microbiol., (24 September 2020) | https://doi.org/10.3389/fmicb.2020.524828
