Archaea

(redirected from archaean)
Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.

Archaea

Evolutionary biology
One of the three domains of living organisms: Archaea, Bacteria and Eukaryota. While Archaea are single-celled, they are unlike bacteria given their independent evolutionary history. Archaea differ from Eukaryota in their ribosomal structure and the presence—in some—of introns in the genome, as well as other features (e.g., different membrane composition).
 
Molecular biology
Archaea are of interest in biotechnology as they have unique biochemical features (e.g., enzymes of theromophiles, such as Taq polymerase, the “workhorse” enzyme of PCR) and are extremely stable at high temperatures. Archaea include metabolic oddities (e.g., extreme halophiles, which live in extremely salty environments), methanogens (which produce methane) and sulphur-dependant extreme thermophiles (which can live in extremely hot environments).

Archaea phyla
• Crenarchaeota
• Euryarchaeota
• Korarchaeota
• Nanoarchaeota
• Thaumarchaeota (recently proposed)

Archaea

( formerly
References in periodicals archive ?
The Properties, which have only seen limited previous exploration, contain multiple large gold anomalies and cover five contiguous licenses over a land package in excess of 2,800km2 of the highly prospective Ndori Greenstone Belt in Kenya, which forms part of the Tanzanian Archaean Craton.
The second column represents a lake of the Archaean Eon (3500 million years ago) and holds an anaerobic community predominated by purple sulfur phototrophic bacteria (Chromatium sp.
1993) differs from the cotectic basaltic magmas inferred to be parental to Archaean megacrystic, layered intrusive, ocean basin, and lunar anorthosite.
Groundwaters of the wheatbelt are contained within heterogeneously weathered Archaean granites and associated igneous rocks, and inset or overlying sediments.
At last, the editors of Science magazine held a press conference in August 1996 to declare the new archaean domain.
old Volcanics in the Archaean Layered Greenstone Succession of the Pilbara Block, Western Australia," Earth and Planetary Science Letters 37 (1978): 421-8.
The investigated area has granites of Archaean age and is unconformably over lained by the Deccan traps with intertrappean beds.
129) that "It will be a long time before such developments can be applied to the whole of the Proterozoic, or to the Archaean, and the present chapter should, therefore, be regarded as an interim report on a challenging topic.
In fact the almost anaerobic blastula stage embryo could reflect the existence of multicellular organisms in the Archaean anoxic world.
In fact, the blastula-stage embryo could reflect the existence of multicellular organisms in the archaean anoxic world.
A geologist with 21 years post graduate experience, which includes 5 years in technical support at the University of Cape Town, 3 years in base metal exploration in northern Namibia, 9 years in mining and exploration in the Archaean terranes of Zimbabwe, and 4 years as an Independent Consultant in East and Southern Africa.