Thermophile Guide, Meaning , Facts, Information and Description
A thermophile is an organism – a type of extremophile – which thrives at relatively high temperatures, up to about 60°C. Many thermophiles are archaea.
Thermophiles have been found in various geothermally heated regions of the earth such as Yellowstone National Park (shown in the image to the right).
As a prerequisite for their survival, thermophiles contain enzymes that can function at high temperature. Some of these enzymes are used in molecular biology (for example heat-stable DNA polymerases for polymerase chain reaction), and in washing agents.
| Table of contents |
|
2 Some thermophilic organisms |
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.
The most commonly used DNA polymerase for the polymerase chain reaction 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. For a few PCR applications, the lack of proofreading by Taq DNA polymerase is a problem.
The DNA polymerase from Thermococcus litoralis was shown to have a proofreading exonuclease activity. Fidelity of DNA synthesis by the Thermococcus litoralis DNA polymerase--an extremely heat stable enzyme with proofreading activity (Mattila P, Korpela J, Tenkanen T, Pitkanen K. Nucleic Acids Res. 1991 Sep 25;19(18):4967-73.) Thermococcus litoralis was isolated from a deep sea hydrothermal vent. This DNA polymerase is marketed as "Vent" polymerase.
Taq DNA polymerase is adequate for most PCR, but one study ("DNA polymerases as engines for biotechnology" by Hamilton SC, Farchaus JW, Davis MC. in "Biotechniques" 2001 31:370-6, 378-80, 382-3). reported that higher fidelity thermostable DNA polymerases such as Vent account for as much as 30% of DNA polymerase sales.
Some thermophilic organisms
The Pompeii worm survives the scalding temperatures surrounding deep-sea hydrothermal vents thanks to a symbiotic relationship with thermophilic bacteria.