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n. pl. ar·chae·a (-kē-ə)
Any of various prokaryotic microorganisms of the domain Archaea, being genetically distinct from bacteria and often living in habitats with extreme environmental conditions such as high temperature or salinity. Also called archaebacterium.

[New Latin Archaeon (back-formed singular of Archaea, domain name), from Greek arkhaion, neuter singular of arkhaios, ancient (in reference to the very ancient separation of the archaea and the eubacteria in evolutionary history); see archaic.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


Plural archaea
Any of a group of microorganisms that resemble bacteria but are different from them in certain aspects of their chemical structure, such as the composition of their cell walls. Archaea usually live in extreme environments, such as very hot or salty ones. The archaea are considered a separate kingdom in some classification systems, but a division of the prokaryotes in others. Also called archaebacterium.
The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
References in periodicals archive ?
"Repeated subcultures gradually enriched the archaeon with extremely slow growth rate and low cell yield," the researchers said in a report.
An endoglucanase, EglA, from the hyperthermophilic archaeon Pyrococcus furiosus hydrolyzes beta-1,4 bonds in mixed-linkage (1-->3), (1-->4)-beta-D-glucans and cellulose.
Cloning, Sequencing, Characterization, and Expression of an Extracellular [alpha]-Amylase from the Hyperthermophilic Archaeon Pyrococcus furiosus in Escherichia coli and Bacillus subtilis.
2007 Molecular Characterization of the phaEChm genes, required for biosynthesis of Poly(3-Hydroxybutyrate) in the extremely halophilic archaeon Haloarcula marismortui.
A highly acidstable and thermostable endo-beta-glucanase from the thermoacidophilic archaeon Sulfolobus solfataricus.
I see it otherwise, as downdrift, the seepage of traits across species." So posits the Archaeon, the 3.8-billion-year-old creature who narrates Johanna Drucker's Downdrift.
For example, Sulfolobus solfataricus (extreme thermoacidophilic archaeon) uses several sugars as the sole carbon and energy source.
No sequence related to nonmethanogenic archaeon, Thermogymnomonas, and unclassified Thermoplasmatales was detected using DGGE-cloning analysis, but the relevant sequences could be retrieved using pyrosequencing.
Tomb et al., "The complete genome sequence of the hyperthermophilic, sulphate-reducing archaeon Archaeoglobus fulgidus," Nature, vol.
The aim of this work was to evaluate, via bioinformatics tools, three mutations in the large subunit of the archaeon Sulfolobus solfataricus (Sso; access code Q97Z83) primase.