Chairperson, Graduate Committee: Mark J. YoungSpuhler, Joshua Lupine2013-06-252013-06-252009https://scholarworks.montana.edu/handle/1/2335My research is focused on the identification and characterization of new archaeal viruses that inhabit the thermal features of Yellowstone National Park (YNP). I have undertaken the systematic survey of more than 90 different thermal features found in Yellowstone through a variety of means including culturing of hosts, MDA amplification, qPCR for known archaeal viruses, 16S rRNA gene analysis of potential resident archaeal hosts, tangential flow and end point filtration approaches to sample new viruses, and general water geochemical analysis. From this work a new host has been isolated from YNP. rDNA analysis has shown a 98% similarity to Thermocladium modestius. Routine culturing of this host has lead to the discovery of multiple viruses. Some of these associated viruses have similar morphology to other known archaeal viruses. The first is a 90x60 nm spindle shaped virus that was originally isolated from Rabbit Creek thermal feature (Temp78, pH3.5). Our initial genomic analysis shows that there is no obvious similarity to other known archaeal viruses, included the SSV spindled shaped viruses for Sulfolobus. The second sequencing effort has come from Nymph Lake thermal feature (Temp 85, pH 2.5). This virus population was gathered from a primary enrichment culture. This culture had two dominate virus morphologies present. The first is a 15nmx210nm rod-shaped virus with tapered ends. The second morphology seen is a 90nm spherical virus. Both of these viruses are hoped to be new additions to the archaeal virus families providing a more in depth view of the necessities of life at high temperatures.enArchaebacteriaThermophilic microorganismsAnaerobic bacteriaVirusesThesisCopyright 2009 by Joshua Lupine Spuhler