Encyclopedia of Astrobiology

Living Edition
| Editors: Muriel Gargaud, William M. Irvine, Ricardo Amils, Henderson James Cleaves, Daniele Pinti, José Cernicharo Quintanilla, Michel Viso

Nanoarchaeota

Living reference work entry
DOI: https://doi.org/10.1007/978-3-642-27833-4_1040-2

Definition

Nanoarchaeota is a phylum of very small parasitic Archaea that branches closest to the root of the archaeal phylogenetic tree. Cells of Nanoarchaeum, the only genus in this phylum, are small coccoids that live as parasites, or possibly as symbionts, of the crenarchaeota Ignicoccus. Cells of Nanoarchaeum are about 0.4 μm in diameter and replicate only when attached to the surface of Ignicoccus. Nanoarchaeum is hyperthermophilic, with an optimal growth of about 90 °C. The metabolism of Nanoarchaeum is unknown, but its host is an autotroph, growing with H2 as electron donor and elemental sulfur as electron acceptor. Isolates from Nanoarchaeum have been obtained from submarine hydrothermal vents as well as terrestrial hot springs. The genome of Nanoarchaeumis only 0.49 Mbp, the smallest genome known. It lacks identifiable genes for most known metabolic functions, including the synthesis of monomers, such as aminoacids, nucleotides, and coenzymes. In addition to the small size...

Keywords

Elemental Sulfur Phylogenetic Tree Electron Donor Bioorganic Chemistry Electron Acceptor 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.Departamento de Biologia MolecularUniversidad Autónoma de MadridMadridSpain