The findings, revealed within the journal Frontiers in Microbiology, go towards the presently predominant views of the function of each viruses and these teams of single-celled organisms referred to as protists within the marine meals webs.
“Our information present that many protist cells include DNA of all kinds of non-infectious viruses however not bacteria, sturdy proof that they’re feeding on viruses slightly than on micro organism,” mentioned research corresponding creator Ramunas Stepanauskas, Director of the Single Cell Genomics Heart at Bigelow Laboratory for Ocean Sciences within the US.
The scientists defined that the predominant mannequin of the function of viruses within the marine ecosystem is that of the “viral shunt,” the place microbes contaminated with viruses lose a considerable fraction of their chemical compounds again to the pool of dissolved natural matter.
Nonetheless, the present research famous that the viral shunt might be complemented by a hyperlink within the marine microbial meals internet which can represent a “sink of viral particles within the ocean.”
In line with the researchers, this discovering “has implications for the stream of carbon via the microbial meals internet.”
Within the research, Stepanauskas and his colleagues sampled floor seawater from the Northwestern Atlantic within the Gulf of Maine within the US in July 2009, and the Mediterranean off Catalonia, Spain in January and July 2016.
They used trendy single-cell genomics instruments to sequence the whole DNA from 1,698 particular person protists within the water, and located proof of protists with or with out related DNA.
The researchers defined that the related DNA might be from symbiotic organisms, ingested prey, or viruses or micro organism sticking to the protists’ exterior.
Whereas the approach may be very delicate, the scientists mentioned it would not instantly present the kind of relationship between a protist and its associates.
The scientists discovered a spread of protists together with teams referred to as alveolates, stramenopiles, chlorophytes, cercozoans, picozoans, and choanozoans.
They mentioned 19 per cent of the genome from the one cell organisms taken from the Gulf of Maine and 48 per cent of these from the Mediterranean had been related to bacterial DNA, suggesting that these protists had eaten micro organism.
However they added that viral sequences had been extra widespread, making up 51 per cent of the protists’ genome from the Gulf of Maine and 35 per cent of these from the Mediterranean, with a frequency of 1 to 52 virus sorts per protist.
In line with the researchers, most of those had been from viruses identified to contaminate micro organism — presumably representing parasites of the protists’ bacterial prey.
However they mentioned choanozoans and picozoans, which solely occurred within the Gulf of Maine pattern, had been completely different since these teams, neither of which have chloroplasts, are poorly identified.
The scientists famous that the choanozoans are of nice evolutionary curiosity because the closest dwelling kin of animals and fungi.
The tiny single-celled organisms had been first found twenty years in the past, and till now, their meals sources had been a puzzle, as their feeding equipment is simply too small for micro organism, however ample for viruses, the researchers mentioned.
Within the present analysis, they discovered that each single one of many choanozoan and picozoan genomes had been related to viral sequences from bacteria-eating viruses referred to as phages, however largely with none bacterial DNA.
The identical genome sequences had been discovered throughout an important variety of species, the research famous.
“It is extremely unlikely that these viruses are able to infecting all of the protists wherein they had been discovered,” mentioned Julia Brown, a co-author of the research on the Bigelow Laboratory for Ocean Sciences.
Primarily based on these findings, the scientists concluded that choanozoans and picozoans “most likely routinely eat viruses.”
“Viruses are wealthy in phosphorus and nitrogen, and will doubtlessly be a superb complement to a carbon-rich food regimen which may embrace mobile prey or carbon-rich marine colloids,” Brown mentioned.
The scientists consider the removing of viruses from the water might scale back the variety of viruses obtainable to contaminate different organisms, whereas additionally shuttling the natural carbon inside virus particles greater up the meals chain.
“Future analysis may think about whether or not protists that eat viruses accumulate DNA sequences from their viral prey inside their very own genomes, or think about how they may shield themselves from an infection,” Brown mentioned.