Definitions by Kayun Nadya

Kayun Nadya
Group 13

Sentence definition
A thermophile is an organism – a type of extremophile – which thrives at relatively high temperatures, above 45 °C(113°F).
Extended definition
A thermophile is an organism – a type of extremophile – which thrives at relatively high temperatures, above 45 °C. Thermophiles are found in various geothermally heated regions of the Earth, such as hot springs and deep sea hydrothermal vents, as well as decaying plant matter such as peat bogs and compost. As a prerequisite for their survival, thermophiles contain enzymes that can function at high temperature. Some of these enzymes are used in molecular biology, and in washing agents. 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. So this is a very interesting group of organisms which should be study more carefully.

http://en.wikipedia.org/wiki/Thermophiles
Nature, vol. 49, 22 February 2001Lynn J. Rothschild and Rocco L. Mancinelli. Life in the extreme environments (p.1094)