Thermophiles produce some of the bright colors of Grand Prismatic Spring, Yellowstone National Park

A thermophile is an organism — a type of extremophile — which thrives at relatively high temperatures, between 40 degrees Celsius (104 degrees Fahrenheit) and 70 degrees Celsius (158 degrees Fahrenheit). The Grand Prismatic Spring in Yellowstone National Park is the largest Hot spring in the United States, and the third largest in the world next to An extremophile is an Organism that thrives in and may even require Physically or Geochemically extreme conditions that are detrimental to the Many thermophiles are archaea.

Thermophiles are found in various geothermally heated regions of the Earth such as hot springs like those in Yellowstone National Park (see image) and deep sea hydrothermal vents, as well as decaying plant matter such as peat bogs and compost. In Geology, geothermal refers to heat sources within the planet EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 The deep sea, or deep layer, is the lowest layer in the Ocean, existing below the Thermocline, at a depth of 1000 fathoms or more A hydrothermal vent is a Fissure in a planet's surface from which geothermally heated Water issues

As a prerequisite for their survival, thermophiles contain enzymes that can function at high temperature. Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins Some of these enzymes are used in molecular biology (for example heat-stable DNA polymerases for PCR), and in washing agents. Molecular biology is the study of Biology at a molecular level A DNA Polymerase is an Enzyme that assists in DNA replication.

Thermophiles are classified into obligate and facultative thermophiles: obligate thermophiles (also called extreme thermophiles) require such high temperatures for growth, while facultative thermophiles (also called moderate thermophiles) can thrive at high temperatures but also at lower temperatures (below 50 °C). Hyperthermophiles are particularly extreme thermophiles for which the optimal temperatures are above 80 °C. A hyperthermophile is an organism that thrives in extremely hot environments— from 60 degrees Celsius (140 degrees Fahrenheit upwards

Importance of enzymes from thermophiles

The enzymes isolated from some extremophiles have proven to be of great use in the biotechnology industry, able to function under conditions that would denature enzymes taken from most "normal" organisms. Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins Biotechnology is Technology based on Biology, especially when used in Agriculture, Food science, and Medicine. Denaturation is a process in which Proteins or Nucleic acids lose their structure (tertiary structure by application of some external stress or compound for

The most commonly used DNA polymerase for the PCR technique is Taq DNA polymerase, originally isolated from Thermus aquaticus, a bacterial species found in surface aquatic locations such as Yellowstone National Park hot springs. A polymerase (EC 2776/7/19/48/49 is an Enzyme whose central function is associated with Polymers of Nucleic acids such as RNA and DNA Taq polymerase is a thermostable DNA polymerase named after the Thermophilic bacterium Thermus aquaticus from which it was originally isolated Thermus aquaticus is a species of Bacterium that can tolerate high temperatures one of several thermophilic bacteria that belong to the Deinococcus-Thermus The Bacteria ( singular: bacterium) are a large group of unicellular Microorganisms Typically a few Micrometres in length bacteria have In Biology, a species is one of the basic units of Biological classification and a Taxonomic rank. A hot spring is a spring that is produced by the emergence of geothermally heated Groundwater from the earth's crust. For a few PCR applications, the lack of proofreading by Taq DNA polymerase is a problem. Proofreading traditionally means reading a proof copy of a text in order to detect and correct any errors

The DNA polymerase from Thermococcus litoralis was shown to have a proofreading exonuclease activity. Exonucleases are enzymes (found as individual enzymes or as parts of larger enzyme complexes that cleave Nucleotides one at a time from an end of a polynucleotide chain ^[1] Thermococcus litoralis was isolated from a deep sea hydrothermal vent. A black smoker or sea vent is a type of Hydrothermal vent found on the Ocean floor. This DNA polymerase is marketed as "Vent" polymerase.

Another heat stable polymerase comes from the organism Pyrococcus furiosus, (Pfu). Pyrococcus furiosus is an extremophilic species of Archaea. It is notable for having an optimum growth temperature of 100°C (a temperature which would This organism grows optimally at 100°C, making it a hyperthermophile. A hyperthermophile is an organism that thrives in extremely hot environments— from 60 degrees Celsius (140 degrees Fahrenheit upwards

Taq DNA polymerase is adequate for most PCR, but one study reported that higher fidelity thermostable DNA polymerases such as Vent account for as much as 30% of DNA polymerase sales. ^[2]

In addition, the study of proteins from thermophilic organisms has provided important insight into the mechanism of protein folding because these proteins must be stable at temperatures that would denature typical proteins. Protein folding is the physical process by which a Polypeptide folds into its characteristic and functional three-dimensional structure. Therefore, understanding how thermophilic proteins have evolved to be stable can yield information about the functional modulation of folding landscapes.

Extreme Thermophiles

Thermophiles, meaning heat-loving organisms, are organisms with an optimum growth temperature of 50 °C or more, a maximum of up to 70 °C or more, and a minimum of about 20 °C, but these are only approximate. Some extreme thermophiles (hyperthermophiles) require a very high temperature (80 °C to 105 °C) for growth. A hyperthermophile is an organism that thrives in extremely hot environments— from 60 degrees Celsius (140 degrees Fahrenheit upwards Their membranes and proteins are unusually stable at these extremely high temperatures. Thus many important biotechnological processes utilize thermophilic enzymes because of their ability to withstand intense heat.

Many of the hyperthermophiles Archea require elemental sulfur for growth. Some are anaerobes that use the sulfur as an electron acceptor during respiration instead of oxygen. Some are lithotrophs that oxidize sulfur to sulfuric acid as an energy source, thus requiring the microorganism to be adapted to very low pH (i. e. it is an acidophile as well as thermophile). These organisms are inhabitants of hot, sulfur-rich environments usually associated with volcanism, such as hot springs, geysers and fumaroles. In these places, especially in Yellowstone National Park, we find a zonation of microorganisms according to their temperature optima. Often these organisma are coloured, due to the presence of photosynthetic pigments.

Genomic and Proteomic Features of Thermophiles

The genome and proteome composition of thermophiles are characterized by overrepresentation of purine bases in protein coding sequences, higher GC-content of the structural RNAs, distinct synonymous codon usage, enhanced usage of positively charged residues and aromatic residues, decrease in polar uncharged residues in the encoded protein. ^[3]

See also

• Hyperthermophile
• Anaerobic digestion
• Mesophile
• Psychrophile

References

External links

• Extreme Thermophile
• Major Groups Of Prokaryotes