Thermus aquaticus

Thermus aquaticus is a heat-tolerant, rod-shaped, gram-negative bacterium in the phylum Deinococcota, whose name means hot water in Latin. Thomas D. Brock and Hudson Freeze of Indiana University reported it in 1969, isolated from Mushroom Spring in the Lower Geyser Basin of Yellowstone National Park, and it has since been found in similar thermal habitats around the world. It grows best at 65 to 70 degrees Celsius and survives between about 50 and 80 degrees. It is a chemotroph that scavenges protein from its surroundings, though it is sometimes found beside photosynthetic cyanobacteria, and it normally respires with oxygen. Cells are cylindrical, 0.5 to 0.8 micrometres across, appearing as short rods or as filaments that can exceed 200 micrometres, and its genome consists of one chromosome and four plasmids. The organism is best known as the source of Taq DNA polymerase, the heat-stable enzyme that made the polymerase chain reaction practical and that earned Kary Mullis a share of the 1993 Nobel Prize in Chemistry; Taq I restriction enzyme and several other thermostable enzymes were also first isolated from it.