Viruses and bacteria battle deep under the sea, fighting for energy as well as a top spot in the ocean ecosystem.
All the drama happens a mile below the ocean's surface. The viruses infect the cells of the bacteria to steal their elemental sulfur, a University of Michigan study found.
After infecting the bacterial cells, the viruses make the bacteria burn the sulfur to release energy. The viruses use the precious energy to replicate and then fill the bacterial cells until they explode.
"We hypothesize that the viruses enhance bacterial consumption of this elemental sulfur, to the benefit of the viruses," study co-author Melissa Duhaime, an assistant research scientist in the U-M Department of Ecology and Evolutionary Biology, said in a school news release.
"We suspect that these viruses are essentially hijacking bacterial cells and getting them to consume elemental sulfur so the viruses can propagate themselves," Anantharaman said.
The viruses are part of an ecosystem clustered around hydrothermal vents deep under the ocean, living alongside 6-foot tube worms, giant clams and mussels, and shrimp.
Besides using the bacteria as an indirect energy source, the viruses are believed to be exchanging genes with the organisms.
"We suggest that the viruses serve as a reservoir of genetic diversity that helps shape bacterial evolution," University of Michigan marine microbiologist and oceanographer Gregory J. Dick said in a statement.
Dick and the research team took samples of water near deep-sea hydrothermal vents under the western Pacific Ocean and the Gulf of California to collect DNA from the viruses and bacteria that thrive there.
Publishing their findings in the online journal Science, the scientists developed genomes for the microbes that are almost complete and also discovered genes for five new viruses.
They additionally found that genes from the common bacterium SUP05, which consumes sulfur, had crosses over into viruses.
"There seems to have been an exchange of genes, which implicates the viruses as an agent of evolution. That's interesting from an evolutionary biology standpoint," Dick said.