An extremophile is an organism that is able to live in extreme environments, i.e. environments with conditions approaching or expanding the limits of what known life can adapt to, such as extreme temperature, radiation, salinity, or pH level.
Deinococcus radiodurans is a bacterium, an extremophile and one of the most radiation-resistant organisms known. It can survive cold, dehydration, vacuum, and acid, and therefore is known as a polyextremophile. It has been listed as the world's toughest known bacterium in The Guinness Book Of World Records.
Deinococcus is in the monotypic family Deinococcaceae, and one genus of three in the order Deinococcales of the bacterial phylum Deinococcota highly resistant to environmental hazards. These bacteria have thick cell walls that give them Gram-positive stains, but they include a second membrane and so are closer in structure to Gram-negative bacteria. Deinococcus survive when their DNA is exposed to high doses of gamma and UV radiation. Whereas other bacteria change their structure in the presence of radiation, such as by forming endospores, Deinococcus tolerate it without changing their cellular form and do not retreat into a hardened structure. They are also characterized by the presence of the carotenoid pigment deinoxanthin that give them their pink color. They are usually isolated according to these two criteria. In August 2020, scientists reported that bacteria from Earth, particularly Deinococcus bacteria, were found to survive for three years in outer space, based on studies conducted on the International Space Station. These findings support the notion of panspermia, the hypothesis that life exists throughout the Universe, distributed in various ways, including space dust, meteoroids, asteroids, comets, planetoids or contaminated spacecraft.
Deinobacterium is a genus in the Deinococcota phylum (Bacteria). Not to be confused with Deinobacter, a disused name for Deinococcus.
Kineococcus radiotolerans is a radiation-resistant, motile, coccus-shaped, gram-positive bacterium.
Streptomyces radiopugnans is a halotolerant and radiation resistant bacterium species from the genus of Streptomyces which has been isolated from radiation polluted soil from the Xinjiang Province in China.
Hymenobacter is a Gram-negative and non-motile bacterial genus from the family Hymenobacteraceae.
Hymenobacter actinosclerus is a bacterium from the genus Hymenobacter which has been isolated from pork chops.
Hymenobacter deserti is a Gram-negative, rod-shaped and non-motile bacterium from the genus Hymenobacter which has been isolated from soil from the desert of Xinjiang in China.
Hymenobacter koreensis is an extremely halophilic and aerobic bacterium from the genus Hymenobacter which has been isolated from a salt mine in Wensu County in China.
Hymenobacter psychrophilus is a Gram-negative, psychrophilic, aerobic, rod-shaped and non-motile bacterium from the genus Hymenobacter which has been isolated from the soil of an industrial estate in Bozen, Italy.
Hymenobacter psychrotolerans is a bacterium from the genus Hymenobacter which has been isolated from permafrost sediments from the Qinghai-Tibet Plateau in China.
Hymenobacter roseosalivarius is a Gram-negative bacterium from the genus Hymenobacter which has been isolated from soil and sandstone from the Antarctica.
Hymenobacter tibetensis is an UV-resistant bacterium from the genus Hymenobacter which has been isolated from the Qinghai-Tibet plateau in China.
Hymenobacter xinjiangensis is a radiation-resistant, Gram-negative, rod-shaped and non-motile bacterium from the genus Hymenobacter which has been isolated from sand from the desert of Xinjiang in China.
Microbacterium radiodurans is a Gram-positive, heterotrophic and strictly aerobic bacterium from the genus Microbacterium which has been isolated from the Gobi desert in China. Microbacterium radiodurans is resistant against UV radiation.
Hymenobacter swuensis is a Gram-negative and non-motile bacterium from the genus Hymenobacter which has been isolated from mountain soil.
Hymenobacter arcticus is a Gram-negative, aerobic, rod-shaped, non-spore-forming and non-motile bacterium from the genus Hymenobacter which has been isolated from the Han River in Korea.
Hymenobacter rubripertinctus is a Gram-negative, aerobic, rod-shaped and non-motile bacterium from the genus Hymenobacter which has been isolated from soil from the Antarctic tundra.
Hymenobacter rutilus is a Gram-negative, aerobic, rod-shaped, non-spore-forming and non-motile bacterium from the genus Hymenobacter which has been isolated from marine sediments from the Kings Bay in Norway.
