Introduction
Bacteriophages are viruses that infect bacteria. Replicating within the bacterial cell, therefore they are obligate parasites. Infection with bacteriophages is restricted to particular strains within a single bacterial species. Phages exist in many forms and infect all living systems such as animals, plants, insects and bacteria, therefore phages are ubiquitous in nature and they have been shown to be found in soil and sediment.
Ecological Impact
The death of the host cell results from the release of the progeny and replication of viral particles About 20-40% of marine bacteria every day have been killed by bacteriophages They play important role in bacterial evolution and ecological systems Have a considerable role in biogeochemical cycles (carbon, nitrogen, sulfur and phosphorous cycles)
