hyperthermophilic

Hyperthermophiles are microorganisms that grow optimally at temperatures above 80°C. Most are archaea, with some bacteria also capable of thriving at extreme heat. Their optimal temperatures commonly fall in the 90–110°C range, and they are found in geothermally heated environments such as deep-sea hydrothermal vents, hot springs, and volcanic areas.

Hyperthermophiles possess adaptations that confer stability to macromolecules and membranes at high temperatures. They often have ether-linked, isoprenoid membrane lipids and, in some species, monolayer membranes that reduce permeability. Their proteins and nucleic acids show enhanced thermostability due to tight packing, salt bridges, and specialized chaperones. DNA stability is further supported by enzymes such as reverse gyrase and robust DNA repair systems.

Metabolism is diverse. Many hyperthermophiles are chemolithoautotrophs that derive energy from hydrogen oxidation, sulfur reduction, or other inorganic redox reactions and fix carbon via autotrophic pathways. Others are chemoorgano­trophs. Most are anaerobic; some tolerate limited oxygen. In vent and hot-spring ecosystems, they drive primary production and participate in sulfur and hydrogen cycles.

Representative taxa include archaea in the Pyrococcus, Thermococcus, and Sulfolobus lineages, as well as the bacterial Aquifex. Notable species include Pyrococcus furiosus, Thermococcus kodakarensis, Pyrolobus fumarii, and Aquifex aeolicus.

Hyperthermophiles are sources of thermostable enzymes used in molecular biology and industrial biocatalysis, and their enzymes are studied for insights into protein stability and the origins of life.