Thermus

Thermus is a genus of thermophilic, mostly Gram-negative bacteria within the phylum Deinococcota. Members are typically rod-shaped, non-spore-forming and aerobic, and they inhabit hot environments such as geothermal springs, volcanic soils, and man-made hot-water systems.

Thermus species are adapted to high temperatures, with growth commonly between 50 and 75°C and optimum growth around 65–75°C. They are chemoorganotrophs that utilize organic substrates and are generally neutrophilic, tolerating neutral to slightly alkaline pH. They occur in hot springs and other thermal habitats worldwide.

Taxonomy and notable species: The genus belongs to the order Thermales, family Thermaceae, in the phylum Deinococcota. Notable species include Thermus aquaticus, Thermus thermophilus, and Thermus filiformis. T. aquaticus remains the best known; its DNA polymerase—Taq polymerase—proved essential for PCR due to high thermostability and activity after heating. Other thermostable enzymes from Thermus are used in industry and research.

Discovery and significance: Thermus aquaticus was described from specimens collected in Yellowstone National Park in 1969 by Thomas Brock and Hudson Freeze. The genus has contributed to molecular biology through thermostable enzymes that enable biotechnological processes and provides a model for studying life in extreme environments.