Interesting fact: the hotsprings of Yellowstone Park yielded an enzyme that is critical for the DNA-copying polymerase chain reaction (PCR):
“In the hot springs of Yellowstone National Park, [American microbiologist Thomas] Brock (then 40, now 85) had discovered a microbe which he christened Thermus aquaticus, a creature that could survive at temperatures as high as 80Â°C. At once, our sense of the life-sustaining zone on Earth expanded. â€œIt was Brock who set the ball rolling,â€ says Michael Danson. â€œWhat has happened since is that the temperature has been set higher and higher. The highest temperature record at which growth has been observed is 121Â°C.â€
Thermus aquaticus was also, serendipitously, the organism that established the enormous potential practical importance of these newly discovered life forms. The point about a thermophilic bacterium is that it needs some very tough enzymes, the catalysts of living processes. Our own enzymes break down very quickly at high temperatures, which is another reason that life outside what we consider a normal temperature range was thought impossible. An enzyme in Thermus aquaticus is now known as Taq DNA polymerase and it has become one of the most important enzymes in microbiology. It made possible the polymerase chain-reaction (PCR) technique for amplifying DNA samples. This led to the uses of DNA in forensic science and, in fact, to much of what we now know about DNA. PCR is a molecular photocopier, making it possible to take very small samples of DNA and repeatedly reproduce them. So now murderers have to be obsessively clean if they are to escape the attentions of the forensic scientist.
On a high school field trip, I once got to replicate my own DNA using PCR, at a lab in the University of British Columbia.