What is Thermus Aquaticus?

The bacterium Thermus aquaticus was first discovered in several hot springs in the Great Fountain area of the Lower Geyser Basin, in Yellowstone National Park, Wyoming. It has since been found isolated in thermal habitats worldwide. The temperature range for Thermus aquaticus is about 50-80ûC (122-176ûF), and has an ideal pH level between 7.5 and 8. As an aerobic bacterium this thermophiles most notable feature is the extremely high optimum growth temperature (70-80ûC). The temperature range somewhat overlaps that of the photosynthetic bacteria in many hot springs, so it lives in association with cyanobacteria obtaining its energy from the photosynthesis of these organisms. However, it may also be found at temperatures too high for photosynthesis, so the Thermus aquaticus lives on tiny amounts of organic matter present in the source water, making it visible to the naked eye. This remarkably unique organism soon revolutionized molecular studies. Its unique biochemistry has become an essentially integral part of the polymerase chain reaction (PCR) method, which was developed to replicate a DNA sequence. When first developed, the DNA polymerase that scientists previously used denatured or broke down at high temperatures (60-90ûC). (A DNA polymerase is an enzyme used to split apart the DNA molecule in order to analyze base sequences, which is a key step for all DNA work.) The DNA polymerase from Thermus aquaticus (Taq polymerase) was found to be heat stable and contributed to an automated, relatively easy means of reproducing even a small segment of DNA a million or billion fold. Taq polymerase is widely used in both medicinal and forensic fields and is therefore in high demand, so if we could isolate a genetically unique species, the implications could be far-reaching. The particular gene that distinguishes Thermus aquaticus from other thermophiles is the 16s rRNA gene. Therefore, this is the gene we need to isolate so that we can compare it to a standard sample of Thermus aquaticusÕ 16s rRNA gene to, in fact, determine whether or not the Thermus aquaticus from Vulcan Hot Spring is genetically different from that of other Thermus aquaticus around the world.

This project was started in 1999 by an advanced biology group here at Cascade High School, but was discontinued until this year of 2003-2004. Now a new group of students has taken on the project in hopes to answer the same questions that the original group asked. The purpose of the project is to determine whether or not Thermus Aquaticus, found in our own Vulcan Hotsprings, are genetically unique to Thermus Aquaticus found around the world. Because of the extreme conditions these bacteria live in, their migration from one hotsprings to another would be nearly impossible. If our sample was genetically unique, it is possible that we would be able to observe evolution in process, and if not could investigate how these bacteria do indeed migrate.

Of course this project has to be taken one step at a time. Getting started took some time for us. After we figured out how to make our media (the culture) things started to move along. As of right now, getting the Thermus Aquaticus to grow is what we are really focusing on. Once we start getting nice looking samples of the bacteria, we can then freeze the samples so that later on this year we can start diving into the DNA part of the project. We will continue to update this page as the project progresses.