Chemolithotrophy

Abstract

Many prokaryotes, Bacteria as well as Archaea, obtain their energy from the oxidation of reduced inorganic compounds such as hydrogen, ammonia, nitrite, sulfide, elemental sulfur, hydrogen and Fe(II) ions. These organisms can derive all their cellular carbon from carbon dioxide, and they are thus able to grow without any organic compounds and without light. Such microorganisms are called chemolithotrophs or chemoautotrophs. Chemolithotrophic life is possible in the presence as well as in the absence of molecular oxygen. Processes mediated by chemolithotrophic prokaryotes include nitrification (the formation of nitrate from ammonia), production of sulfuric acid from sulfide and elemental sulfur, and the formation of methane from hydrogen and carbon dioxide. Some ecosystems, for example those that develop around deep‐sea hot vents, are entirely driven by carbon fixed by chemolithotrophic microorganisms.

Key concepts

  • Certain groups of prokaryotes obtain their energy from the oxidation of reduced inorganic compounds such as sulfide, ammonia and hydrogen, and use carbon dioxide as carbon source. These organisms are called chemolithotrophs or chemoautotrophs.

  • Chemolithotrophy is widespread in the two domains of prokaryotes: the Bacteria and the Archaea.

  • Many chemolithotrophs use molecular oxygen as electron acceptor, but chemolithotrophy is also possible in the absence of oxygen. Nitrate, sulfate, elemental sulfur or carbon dioxide serves as electron acceptors for certain groups of chemolithotrophs.

  • Nitrification, or the oxidation of ammonia via nitrite to nitrate by chemolithotrophic bacteria, is a key process in the global nitrogen cycle.

  • Two types of anaerobic chemolithotrophs oxidize hydrogen with carbon dioxide as electron acceptor: methanogens and homoacetogens, producing methane and acetate, respectively.

  • Chemolithotrophs participate in the biogeochemical cycles of certain metals (iron, manganese) and metalloids (arsenic).

  • In some environments such as deep‐sea hydrothermal vents and certain underground caves, chemolithotrophic primary production driven by the oxidation of hydrogen sulfide provides the basis for the functioning of the ecosystem.

Keywords: chemolithotrophy; chemoautotrophy; nitrification; sulfide oxidation; prokaryotes

Figure 1.

Filaments of Beggiatoa full of granules of elemental sulfur, from sulfide‐containing water in an underground karstic cave in Israel. Photograph by the author.

Figure 2.

Schematic representation of the energy and the carbon metabolism of aerobic chemolithotrophic bacteria such as ammonia oxidizers (e.g. Nitrosomonas), sulfide oxidizers (e.g. Thiobacillus and Beggiatoa) or hydrogen oxidizers (e.g. Ralstonia/Wautersia). Electrons flow from a reduced inorganic electron donor to oxygen with the formation of oxidation products. The energy produced in the course of the respiratory electron transport (ATP) is used for the autotrophic fixation of carbon dioxide. The inorganic electron donors that serve for the production of energy also provide the necessary electrons for carbon dioxide reduction. For further details see text.

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Further Reading

Abeliovich A (2006) The nitrite‐oxidizing bacteria. In: Dworkin M, Falkow S, Rosenberg E, Schleifer KH and Stackebrandt E (eds) The Prokaryotes. A Handbook on the Biology of Bacteria: Ecophysiology and Biochemistry, vol. 5, pp. 861–872. New York: Springer.

Bock E and Wagner M (2006) Oxidation of inorganic nitrogen compounds as an energy source. In: Dworkin M, Falkow S, Rosenberg E, Schleifer KH and Stackebrandt E (eds) The Prokaryotes. A Handbook on the Biology of Bacteria: Ecophysiology and Biochemistry, vol. 2, pp. 457–495. New York: Springer.

Cavanaugh CM, McKiness ZP, Newton ILG and Stewart FJ (2006) Marine chemosynthetic symbioses. In: Dworkin M, Falkow S, Rosenberg E, Schleifer KH and Stackebrandt E (eds) The Prokaryotes. A Handbook on the Biology of Bacteria: Ecophysiology and Biochemistry, vol. 1, pp. 475–507. New York: Springer.

Kelly DP and Wood AP (2006) The chemolithotrophic prokaryotes. In: Dworkin M, Falkow S, Rosenberg E, Schleifer KH and Stackebrandt E (eds) The Prokaryotes. A Handbook on the Biology of Bacteria: Ecophysiology and Biochemistry, vol. 2, pp. 441–456. New York: Springer.

Koops H‐P, Purkhold U, Pommerening‐Röser A, Timmermann G and Wagner M (2006) The lithoautotrophic ammonia‐oxidizing bacteria. In: Dworkin M, Falkow S, Rosenberg E, Schleifer KH and Stackebrandt E (eds) The Prokaryotes. A Handbook on the Biology of Bacteria: Ecophysiology and Biochemistry, vol. 5, pp. 778–811. New York: Springer.

Madigan MT, Martinko JM, Dunlap PV and Clark DP (2009) Brock Biology of Microorganisms, 12th edn, San Francisco: Pearson/Benjamin Cummings.

Prosser JI (1989) Autotrophic nitrification in bacteria. Advances in Microbial Physiology 30: 235–289.

Robertson LA and Kuenen JG (2006) The colorless sulfur bacteria. In: Dworkin M, Falkow S, Rosenberg E, Schleifer KH and Stackebrandt E (eds) The Prokaryotes. A Handbook on the Biology of Bacteria: Ecophysiology and Biochemistry, vol. 2, pp. 985–1011. New York: Springer.

Schlegel HG and Bowien B (eds) (1989) Autotrophic Bacteria. Madison: Science Tech Publishers.

Winogradsky S (1949) Microbiologie du Sol. Problèmes et Méthodes. Paris: Masson et Cie.

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How to Cite close
Oren, Aharon(Sep 2009) Chemolithotrophy. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0021153]