Odd-looking viruses are waging war on an ocean-living bacterium that’s key to the Earth’s carbon cycle, say researchers.
In one corner is the Earth’s most abundant organism: SAR11, an ocean-living bacterium that survives where most other cells would die and plays a major role in the planet’s carbon cycle. It had been theorized that SAR11 was so small and widespread that it must be invulnerable to attack.
In the other corner, and so strange looking that scientists previously didn’t even recognize what they were, are “Pelagiphages,” viruses now known to infect SAR11 and routinely kill millions of these cells every second.
How this fight turns out is of more than casual interest, because SAR11 has a huge effect on the amount of carbon dioxide that enters the atmosphere, and the overall biology of the oceans.
“There’s a war going on in our oceans, a huge war, and we never even saw it,” says Stephen Giovannoni, a professor of microbiology at Oregon State University. “This is an important piece of the puzzle in how carbon is stored or released in the sea.” The analysis shows that the new viruses—like their hosts—are the most abundant on record.