Microbiology in Yellowstone

It seems incredible that life can exist in the extreme heat of the hot springs at Yellowstone! However, in the 1960's researchers discovered that microorganisms were thriving in Yellowstone's hot springs. Scientists are interested in how these organisms, called thermophiles ("heat-loving" microorganisms), are able to survive in such high temperatures that would be fatal to many living organisms. The key to thermophiles' survival, scientists believe, is their production of temperature resistant enzymes.

All living cells produce enzymes which make possible the processes of life, such as food utilization, growth and reproduction. Most of the enzymes that have been studied by scientists will denature, or unwind, at high temperatures. Thermophiles produce enzymes that survive temperatures up to nearly the boiling point of water. These heat resistant enzymes have been found to be useful in several commercial applications, where regular temperature enzymes would not be effective.

[MIcrobial mat]

Microbial mat at Bead Geyser

Scientists have also developed new techniques to take advantage of heat resistant enzymes. One of the most important applications developed in the last decade has been the polymerase chain reaction. This biological technique uses an enzyme produced by a thermophilic bacteria which was found by researcher Thomas Brock in a Yellowstone hot spring. The enzyme, Taq polymerase, resists many cycles of high temperatures and allows researchers to make many copies of short pieces of DNA. This technique is very important in the biological research, medical and forensic fields and enables scientists to diagnose medical diseases, and to conduct DNA fingerprinting and genetic screening.

Scientists are also interested in studying life in the hot springs at Yellowstone because organisms found there may reveal clues about the origins of life on earth and relationships of current life on earth. efore the discovery of microorganisms living in extreme environments, biological life was divided into two kingdoms, bacteria and eukaryotes Eukaryotes were thought to be more highly evolved than bacteria, having a multi-celled organization and a nucleus to separate their DNA from the rest of the cell. With the advent of molecular biological techniques, scientists have been able to determine evolutionary relationships in organisms by the genetic similarity in their RNA. Through these techniques, researcher Carl Woese and colleagues have determined that many of the organisms in hot spring environments are actually a third kingdom, the Archaea.