Which bacterium produces the enzyme used in PCR, a technique that amplifies DNA?

Thermus aquaticus produces the heat-stable enzyme used in PCR, a technique that amplifies DNA.

T. aquaticus is a thermophilic bacterium discovered in 1969 in a hot spring in Yellowstone National Park. Its enzymes remain functional at temperatures that would damage many proteins from ordinary organisms. This property led researchers to isolate Taq polymerase, a DNA polymerase that can withstand the repeated heating cycles used in polymerase chain reaction.

PCR requires cycles of heating to separate DNA strands, cooling to let primers bind, and warming to extend new strands. Before a heat-stable polymerase was adopted, researchers had to add fresh enzyme after each heating step. Taq polymerase made the process practical and helped transform molecular biology, medical testing, and forensic analysis.

The enzyme is named Taq polymerase after the first part of the species name. T. aquaticus itself is not the organism that PCR detects; it supplies the enzyme that copies target DNA in the reaction.