Viruses Hijack Deep-Sea Bacteria During Hydrothermal Vent War

Deep beneath the ocean, there's a war taking place. Armies of viruses and bacteria fight against one another within the mineral-rich water billowing from seafloor hot springs called hydrothermal vents. Now, scientists have taken a closer look at this interaction, reveal how and why this war is occurring.

In order to get a better look at these conflicts, the researchers collected water samples from the Eastern Lau Spreading Center in the Western Pacific Ocean and the Guaymas Basin in the Gulf of California. These samples were taken at depths of more than 6,000 feet near hydrothermal vents spewing water at 500 degrees Fahrenheit.

"Our findings suggest that viruses in the dark oceans indirectly access vast energy sources in the form of elemental sulfur," said Gregory Dick, one of the researchers, in a news release. In fact, the scientists believe that the viruses are essentially hijacking bacterial cells and forcing them to consume sulfur so that they can propagate themselves.

More specifically, the scientists discovered the sulfur-consuming bacterium SUP05 within the samples. Within this bacterium, though, they found the genes from five previously unknown viruses. It's possible that these viruses prey on SUP05 and extract energy from sulfur compounds.

"We hypothesize that the viruses enhance bacterial consumption of this elemental sulfur to benefit the viruses," said Melissa Duhaime, one of the researchers, in a news release. The revved-up metabolic reactions then release energy that the viruses then use.

These new findings may help researchers better understand how marine biogeochemical cycles, including the sulfur cycle, will respond to environmental changes, such as the expansion of dead zones. In addition, these findings reveal the important interaction between viruses and this bacterium. This, in turn, reveals a little bit more about the hydrothermal vents deep beneath the surface of the ocean.

The findings are published in the journal Science.