3.8 KiB
| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Archaea | 9/9 | https://en.wikipedia.org/wiki/Archaea | reference | science, encyclopedia | 2026-05-05T07:15:06.056512+00:00 | kb-cron |
==== Commensalism ==== Some archaea are commensals, benefiting from an association without helping or harming the other organism. For example, the methanogen Methanobrevibacter smithii is by far the most common archaean in the human flora, making up about one in ten of the prokaryotes in the human gut. In termites and in humans, these methanogens may in fact be mutualists, interacting with other microbes in the gut to aid digestion. Archaean communities associate with a range of other organisms, such as on the surface of corals, and in the region of soil that surrounds plant roots (the rhizosphere).
==== Parasitism ==== Although Archaea do not have a historical reputation of being pathogens, Archaea are often found with similar genomes to more common pathogens like E. coli, showing metabolic links and evolutionary history with today's pathogens. Archaea have been inconsistently detected in clinical studies because of the lack of categorization of Archaea into more specific species. The reduced genome of Candidatus Sukunaarchaeum mirabile suggests it is a specialized parasite highly dependant on its dinoflagellate host.
== Significance in technology and industry ==
Extremophile archaea, particularly those resistant either to heat or to extremes of acidity and alkalinity, are a source of enzymes that function under these harsh conditions. These enzymes have found many uses. For example, thermostable DNA polymerases, such as the Pfu DNA polymerase from Pyrococcus furiosus, revolutionized molecular biology by allowing the polymerase chain reaction to be used in research as a simple and rapid technique for cloning DNA. In industry, amylases, galactosidases and pullulanases in other species of Pyrococcus that function at over 100 °C (212 °F) allow food processing at high temperatures, such as the production of low lactose milk and whey. Enzymes from these thermophilic archaea also tend to be very stable in organic solvents, allowing their use in environmentally friendly processes in green chemistry that synthesize organic compounds. This stability makes them easier to use in structural biology. Consequently, the counterparts of bacterial or eukaryotic enzymes from extremophile archaea are often used in structural studies. In contrast with the range of applications of archaean enzymes, the use of the organisms themselves in biotechnology is less developed. Methanogenic archaea are a vital part of sewage treatment, since they are part of the community of microorganisms that carry out anaerobic digestion and produce biogas. In mineral processing, acidophilic archaea display promise for the extraction of metals from ores, including gold, cobalt and copper. Archaea host a new class of potentially useful antibiotics. A few of these archaeocins have been characterized, but hundreds more are believed to exist, especially within Halobacteria and Sulfolobus. These compounds differ in structure from bacterial antibiotics, so they may have novel modes of action. In addition, they may allow the creation of new selectable markers for use in archaeal molecular biology.
== See also ==
== References ==
== Further reading ==
== External links ==
=== General === Introduction to the Archaea, ecology, systematics and morphology Oceans of Archaea – E.F. DeLong, ASM News, 2003
=== Classification === NCBI taxonomy page on Archaea Genera of the domain Archaea – list of Prokaryotic names with Standing in Nomenclature Shotgun sequencing finds nanoorganisms – discovery of the ARMAN group of archaea
=== Genomics === Browse any completed archaeal genome at UCSC Comparative Analysis of Archaeal Genomes Archived 16 February 2013 at the Wayback Machine (at DOE's IMG system)