A thermoacidophile is an extremophilic microorganism that is both thermophilic and acidophilic; i.e., it can grow under conditions of high temperature and low pH.[1] The large majority of thermoacidophiles are archaea (particularly the Thermoproteota and "Euryarchaeota") or bacteria, though occasional eukaryotic examples have been reported.[2][3] Thermoacidophiles can be found in hot springs and solfataric environments, within deep sea vents, or in other environments of geothermal activity.[1]: 602  They also occur in polluted environments, such as in acid mine drainage.[4]

An apparent tradeoff has been described between adaptation to high temperature and low pH; relatively few examples are known that are tolerant of the extremes of both environments (pH < 2, growth temperature > 80°C).[1]: 602  Many thermoacidophilic archaea have aerobic or microaerophilic metabolism,[1]: 602  although obligately anaerobic examples (e.g. the Acidilobales) have also been identified.[5]

Sequencing the genome of a thermoacidophilic eukaryote, the red algae Galdieria sulphuraria, revealed that its environmental adaptations likely originated from horizontal gene transfer from thermoacidophilic archaea and bacteria.[2]

Further readingEdit

  • Stetter, Karl O. (2011). "History of Discovery of Hyperthermophiles". In Horikoshi, Koki; Antranikian, Garabed; Bull, Alan T.; Robb, Frank T.; Stetter, Karl O. (eds.). Extremophiles handbook. Tokyo: Springer. pp. 403–425. ISBN 9784431538974.


  1. ^ a b c d Zaparty, Melanie; Siebers, Bettina (2011). "Physiology, Metabolism, and Enzymology of Extremophiles". In Horikoshi, Koki; Antranikian, Garabed; Bull, Alan T.; Robb, Frank T.; Stetter, Karl O. (eds.). Extremophiles handbook. Tokyo: Springer. pp. 602–633. ISBN 9784431538974.
  2. ^ a b Schönknecht, G; Chen, WH; Ternes, CM; Barbier, GG; Shrestha, RP; Stanke, M; Bräutigam, A; Baker, BJ; Banfield, JF; Garavito, RM; Carr, K; Wilkerson, C; Rensing, SA; Gagneul, D; Dickenson, NE; Oesterhelt, C; Lercher, MJ; Weber, AP (8 March 2013). "Gene transfer from bacteria and archaea facilitated evolution of an extremophilic eukaryote". Science. 339 (6124): 1207–10. Bibcode:2013Sci...339.1207S. doi:10.1126/science.1231707. PMID 23471408.
  3. ^ Skorupa, DJ; Reeb, V; Castenholz, RW; Bhattacharya, D; McDermott, TR (November 2013). "Cyanidiales diversity in Yellowstone National Park" (PDF). Letters in Applied Microbiology. 57 (5): 459–66. doi:10.1111/lam.12135. PMID 23865641.
  4. ^ Baker-Austin, C; Dopson, M (April 2007). "Life in acid: pH homeostasis in acidophiles". Trends in Microbiology. 15 (4): 165–71. doi:10.1016/j.tim.2007.02.005. PMID 17331729.
  5. ^ Bonch-Osmolovskaya, Elisaveta (2012). "Metabolic diversity of thermophilic prokaryotes—what's new.". Extremophiles: microbiology and biotechnology. Norfolk: Caister Academic Press. pp. 109–31. ISBN 9781904455981.