phages
Viruses can be found almost anywhere there is life, including living within prokaryotes. A phage is a virus that infects prokaryotes. Phages are estimated to be the most widely distributed and diverse entities in the biosphere, even more numerous than prokaryotic organisms. Phages can be found everywhere their hosts are found, such as in soil, in the intestine of animals, or seawater. Up to 10 9 virions have been found in a milliliter of seawater, and up to 70 percent of marine bacteria may be infected by phages. They are also found in drinking water and in some foods, including fermented vegetables and meats, where they control the growth of bacteria.