Thermococci Explained

In taxonomy, the Thermococci are a class of microbes within the Euryarchaeota.^[1]

They live in extremely hot environments, such as hydrothermal vents, and they have optimal growth temperatures above 80 °C. Thermococcus and Pyrococcus (literally "balls of fire") are both obligately anaerobic chemoorganotrophs.

Thermococcus prefers 70–95 °C and Pyrococcus 70-100 °C. Palaeococcus helgesonii, recently discovered in the Tyrrhenian Sea, is an aerobic chemoheterotrophic that grows at temperatures of 45–85 °C with an optimal temperature of 80 °C.Thermococcus gammatolerans sp. nov. was recently discovered in the Guaymas Basin, and it grows at temperatures from 55–95 °C with an optimal temperature around 88 °C with an optimal pH of 6. It has pronounced radioresistance and can survive gamma radiation at 30 kGy.^[2]

Thermococcus grows on organic substrates where there is a higher capacity of elemental sulfur. This archaeon mostly grows between temperatures 60–100 degrees Celsius. The average temperature where they thrive is around 85 degrees Celcius.

The DNA structure has a cicular genome with around 2,353 coding sequence, and 2,306 are identified.

See also

• List of Archaea genera

Further reading

• Cavalier-Smith . T . 2002 . The neomuran origin of archaebacteria, the negibacterial root of the universal tree and bacterial megaclassification . Int. J. Syst. Evol. Microbiol. . 52 . 7–76 . 11837318 . Pt 1 . 10.1099/00207713-52-1-7. free .
• Marguet. Evelyne. Gaudin. Marie. Gauliard. Emilie. Fourquaux. Isabelle. le Blond du Plouy. Stephane. Matsui. Ikuo. Forterre. Patrick. Membrane vesicles, nanopods and/or nanotubes produced by hyperthermophilic archaea of the genus Thermococcus. Biochemical Society Transactions. 2013. 41. 1. 436–442. 10.1042/BST20120293. 23356325.
• Woese . CR . Kandler O . Wheelis ML . 1990 . Towards a natural system of organisms: proposal for the domains Archaea, Bacteria, and Eucarya . Proc. Natl. Acad. Sci. USA . 87 . 4576–4579 . 2112744 . 10.1073/pnas.87.12.4576 . 12 . 54159 . 1990PNAS...87.4576W. free .

• Book: Zillig W . Reysenbach AL . 2001 . Class IV (sic) [V]. Thermococci class. nov. . Bergey's Manual of Systematic Bacteriology Volume 1: The Archaea and the deeply branching and phototrophic Bacteria . 2nd . DR Boone . RW Castenholz . 169 . Springer Verlag . New York . 978-0-387-98771-2 .
• Book: Garrity GM . Holt JG . 2001 . Phylum AII. Euryarchaeota phy. nov. . Bergey's Manual of Systematic Bacteriology Volume 1: The Archaea and the deeply branching and phototrophic Bacteria . 2nd . DR Boone . RW Castenholz . 169 . Springer Verlag . New York . 978-0-387-98771-2 . https://archive.org/details/bergeysmanualofs00boon/page/169 .

Notes and References

1. See the NCBI webpage on Thermococci. Data extracted from the Web site: NCBI taxonomy resources . . 2007-03-19.
2. News: Airspade . 13 June 2023.