Strain 121 (''Geogemma barossii'') is a single-

cell Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Locations * Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery ...

microbe A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in olde ...

of the

domain Domain may refer to: Mathematics *Domain of a function, the set of input values for which the (total) function is defined **Domain of definition of a partial function **Natural domain of a partial function **Domain of holomorphy of a function * Do ...

Archaea Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebac ...

. First discovered off

Puget Sound Puget Sound ( ) is a sound of the Pacific Northwest, an inlet of the Pacific Ocean, and part of the Salish Sea. It is located along the northwestern coast of the U.S. state of Washington. It is a complex estuarine system of interconnected ma ...

near a

hydrothermal vent A hydrothermal vent is a fissure on the seabed from which geothermally heated water discharges. They are commonly found near volcanically active places, areas where tectonic plates are moving apart at mid-ocean ridges, ocean basins, and hotspot ...

, it is a

hyperthermophile A hyperthermophile is an organism that thrives in extremely hot environments—from 60 °C (140 °F) upwards. An optimal temperature for the existence of hyperthermophiles is often above 80 °C (176 °F). Hyperthermophiles are often within the doma ...

, able to reproduce at , hence its name. It was (at the time of its discovery) the only known form of

life Life is a quality that distinguishes matter that has biological processes, such as signaling and self-sustaining processes, from that which does not, and is defined by the capacity for growth, reaction to stimuli, metabolism, energ ...

that could tolerate such high

temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer. Thermometers are calibrated in various temperature scales that historically have relied o ...

s. A temperature of is biostatic for Strain 121, meaning that although growth is halted, the archaeon remains viable, and can resume reproducing once it has been transferred to a cooler medium. The ability to grow at is significant because medical equipment is exposed to this temperature for sterilization in an

autoclave An autoclave is a machine used to carry out industrial and scientific processes requiring elevated temperature and pressure in relation to ambient pressure and/or temperature. Autoclaves are used before surgical procedures to perform sterilizat ...

. Prior to the 2003 discovery of Strain 121, a fifteen-minute exposure to autoclave temperatures was believed to kill all living organisms. However, Strain 121 is not infectious in humans, because it cannot grow at temperatures near . Strain 121

metabolizes Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cell ...

by reducing

iron oxide Iron oxides are chemical compounds composed of iron and oxygen. Several iron oxides are recognized. All are black magnetic solids. Often they are non-stoichiometric. Oxyhydroxides are a related class of compounds, perhaps the best known of whic ...

. The maximum growth temperature of strain 121 is 8 °C higher than the previous record holder, ''

Pyrolobus fumarii ''Pyrolobus fumarii'' (literally the "firelobe of the chimney") is a species of archaea known for its ability to live at extremely high temperatures that kill most organisms.Joseph E. Armstrong. 2014. How the Earth Turned Green: A Brief 3.8-Billio ...

'' (Tmax=113 °C). However, it appears highly improbable that strain 121 marks the upper limit of viable growth temperature. It may very well be the case that the true upper limit lies somewhere in the vicinity of 140 to 150 °C, the temperature range where molecular repair and resynthesis becomes unsustainable.

References

* *Cowan, D. (2004). “The Upper Temperature for Life – Where Do We Draw the Line?” ''Trends in Microbiology (Regular Ed.)'', vol. 12, no. 2, Elsevier Ltd, pp. 58–60, https://doi.org/10.1016/j.tim.2003.12.002.

External links

Guardian News
"Microbe from Depths Takes Life to Hottest Known Limit"
How Hot is Too Hot for Earth-Style Life?
{{Taxonbar, from=Q3267859 Thermoproteota Thermophiles Archaea described in the 21st century

See also

References

External links