thermophilic Describing an organism that lives and grows optimally at extremely high temperatures, typically over 40°C. The majority are prokaryotes, such as the archaebacteria found in hot springs and in undersea hydrothermal vents (thermoacidophils); some of these (called hyperthermophiles) thrive at temperatures above 80°C and can survive at temperatures above the boiling point of water. Some eukaryotes, especially certain protoctists and fungi, are capable of surviving temperatures up to about 60°C. Thermophiles have various adaptations in order to thrive at such high temperatures. For example, their proteins and nucleic acids have structural modifications that give them much greater heat stability, so that the cell machinery is able to function. Also, the chemical makeup of their cell membranes is adapted, for example by inclusion of lipids rich in saturated fatty acids. Compare mesophilic; psychrophilic.

ther·mo·phile / ˈ[unvoicedth]ərməˌfīl/ • n. Microbiology a bacterium or other microorganism that grows best at higher than normal temperatures.DERIVATIVES: ther·mo·phil·ic / ˌ[unvoicedth]ərməˈfilik/ adj.

thermophile An extremophile (domain Archaea) that thrives in environments where the temperature is high, typically up to 60°C. Compare hyperthermophile.

thermophile An extremophile (domain Archaea) that thrives in environments where the temperature is high, typically up to 60°C. Compare HYPERTHERMOPHILE.

thermophile An extremophile (domain Archaea) that thrives in environments where the temperature is high, typically up to 60°C. Compare HYPERTHERMOPHILE.