This is Thermus aquaticus, the first extremophile ever discovered. That wasn’t until 1966, when Dr. Thomas Brock and an undergraduate named Hudson Freeze, both from Indiana University’s biology department, visited Yellowstone National Park. They isolated this bacterium that had no problem surviving the extremely high temperatures of Yellowstone’s hot springs.

Taq, as Brock and Freeze nicknamed it, holds a special place in science not only for being the original extremophile, but also because it is the source of Taq polymerase. Until 1983, when the polymerase chain reaction (PCR) technique was invented, scientists had a hard time studying DNA. PCR would allow scientists to make many copies of (or “amplify”) the DNA sequences they wanted to look at. But there was another problem: PCR required high heat, and how could polymerase be kept working at those temperatures? Well, polymerase from normal organisms couldn’t, but guess whose could! Scientists started using polymerase from the very same strain that Brock and Freeze brought back from Yellowstone almost 20 years earlier. The rest is history. PCR using Taq polymerase has allowed for the creation of drugs and vaccines, genetic tests for diseases, tools used in crime scene analysis, and sequencing of the human genome, among so many other scientific advances.

Not too bad for a “mere” bacterium!