Sulfolobus islandicus microbes can go dormant, ceasing to grow and reproduce, in order to protect themselves from infection by Sulfolobus spindle-shaped virus 9 (SSV9).
The dormant microbes are able to recover if the virus goes away within 24 to 48 hours, otherwise they die.
Sulfolobus is a species of archaea (a domain of single-celled organisms distinct from bacteria) found in acidic hot springs all over the world, where free viruses are not as common as in other environments. These microbes will go dormant in the presence of just a few viruses, whether active or inactive. While inactivated virus particles cannot infect a host, researchers found they could still cause dormancy, and ultimately, death in Sulfolobus.