Archaea extremophilic

Archaea are usually extremophiles, living at extremes of salt, of temperature or of pH. (At high temperatures (80°C), they often obtain energy from H2, CO, CH4 and H2S... 

Archaea Special membrane lipids, coenzymes and uses of nickel (several specialist types see under bacteria) Extremophiles of various kinds. Use of sulfate and limited use of light and 02... 

Bacteria-like microbes found in extreme environments ( extremophiles ) were sometimes presumed to belong exclusively to the specialized domain known as Archaea. However, it has transpired that the arrangement of microbes in ecological niches was not as simple as this - many Archaea have been found in temperate zones and in ecosystems similar to those occupied by bacteria, and some conventional microbes occupy extreme environments. 

Cannio, R. Contursi, P. Rossi, M. Bartolucci, S. Thermoadaptation of a mesophilic hygromycin B phosphotransferase by directed evolution in hy-perthermophilic Archaea selection of a stable genetic marker for DNA transfer into Sulfolobus solfataricus. Extremophiles, 5, 153-159 (2001)... 

D. Hafenbradl, H. W. Jannasch, and K. O. Stetter, I yrolohus fumarii, gen. and sp. nov., represents a novel group of archaea, extending the upper temperature limit for life to 113°C, Extremophiles 1997,... 

Jolivet, E., Corre, E., L Haridon, S., Forterre, P., and Prieur, D. 2004. Thermococcus marinus sp. nov. and Thermococcus radiotolerans sp. nov., two hyperthermophilic archaea from deep-sea hydrothermal vents that resist ionizing radiation. Extremophiles 8 219-227. 

Extremophiles, loosely defined as members of the domains Archaea and Bacteria that are tolerant of extremes of temperature, salinity, pressure, and acidity (for reviews, see Horikoshi and Grant, 1998), usually are characterized by membrane components that add an additional degree of toughness to the integrity of the membrane. Above, we mentioned that long-chain carotenoids that intercalate into the membrane and may span the bilayer confer a high level of stability to the membrane. There are other unusual components of the membranes of extremophiles that also may serve this type of function. In the... 

Extremophilic bacteria employ mechanisms analogous to those used by thermophilic members of the Archaea. In some anaerobic thermophilic bacteria, C30 dicarboxylic acids may provide 10-20% of the acyl chains of membrane lipids (Langworthy and Pond, 1986). These acyl chains may be esterified to a glycerol molecule at each end of the C30 chain to form a membrane-spanning lipid with a high ability to stabilize the membrane against thermal perturbation. 

Ausili A, Cobucci-Ponzano B, Di Lauro B, D Avino R, Perugino G, Bertoli E, Scire A, Rossi M, Tanfani F, Moracci M. A comparative infrared spectroscopic study of glycoside hydrolases from extremophilic archaea revealed different molecular mechanisms of adaptation to high temperatures. Proteins 2007 67 991-1001. 

These extremophile microorganisms and Archaea, which constitute the 3rd domain of life (the three domains of life being Bacteria, Archaea and Eukaiy a), also use QS. Thus, the study of QS in these microorganisms is one of the expanding domains of research because of their biotechnological effects, notably for the use of extracellular enzymes or metabolites, but also for knowledge of the mechanisms of adaptation of microorganisms. 

The scientific journal Extremophiles, published by Springer since 1997, is entirely dedicated to organisms living in extreme conditions, mainly Archaea. For the year 2003 its impact factor (IF) was 2.0. The International Sodety for Extremophiles (ISE), based in Japan, organizes international congresses, of which the first took place in... 

The discovery of extreme environments and studies of extremophiles not only offered important insights into biology and evolution but also provided clues to extraterrestrial life since these microorganisms are widely accepted to represent the earliest forms of life. Moreover, taxonomic studies on extremophilic microorganisms enabled Archaea to find its place as the third domain in the evolutionary tree of life [54, 61],... 

Higher organisms were believed to be unable to withstand extreme environments most probably because of their cellular complexity and compartmentalization. Therefore research on extremophiles has focused mainly on organisms belonging to the Archaea and Bacteria kingdoms. However, a significant number of eukaryotes, both unicellular and multicellular, have evolved to live and thrive in extreme environments (e.g. Alvinella pompejana, Tetrahymena thermophila and Dunaliella salina). Hence, extremophiles span all three domains of life Archaea, Bacteria and Eukarya [61]. 

However, there are organisms that live under extreme physical or geochemical conditions, the extremophiles. Most of them are microbes including representatives of all three domains (Bacteria, Archaea, andEucarya). Some types of extremophiles are listed in Table 2.1. 

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