Science / Medicine : Viral Infections May Kill Atlantic Bacteria, Algae

Viral infections may kill as much as 60% of the blue-green algae and bacteria in parts of the Atlantic Ocean, USC biologists Jed A. Fuhrman and Lita M. Proctor reported last week in Nature. Their discovery follows a recent Norwegian finding that viruses are hundreds of times more abundant in the ocean than had previously been believed.

When the bacteria and algae die from the infection, they burst open, spilling their contents so that they can be eaten by other bacteria. Researchers had previously believed that most bacteria were eaten by protozoa, which were in turn consumed by higher organisms that become food for fish.

When the bacteria burst as a result of infection, Fuhrman said, “the organic material of the dead bacteria is consumed by neighboring bacteria rather than being passed up the food chain.” Because viruses often carry genetic information between bacteria, Fuhrman speculated, the widespread infection may speed evolution of viruses, increasing their ability to adapt to changing conditions.