N-147. Diversity and Biogeography of Korarchaeota in Hot Springs

R. L. Miller-Coleman1, K. C. Costa1, E. L. Shock2, B. P. Hedlund1;
1Sch. of Life Sciences, Univ. of Nevada, Las Vegas, NV, 2Sch. of Earth and Space Exploration, Arizona State Univ., Tempe, AZ.

Microorganisms have traditionally been characterized based on their morphology, physiology and phylogenetic placement, and such characterization typically requires the successful cultivation and isolation of the organism. However, this formula does not account for the importance of a microorganism’s habitat, which is intimately linked to its physiology. The Korarchaeota comprise a deeply branching archaeal lineage that has proven difficult to cultivate and isolate and, consequently, has remained largely uncharacterized. The aim of the current study is to characterize the natural habitat of Korarchaeota and to evaluate their physiochemical and biogeographical distribution in terrestrial hot springs of the Great Basin and Yellowstone National Park. Sediment was collected from over 100 hot springs with temperatures ranging from 35°C to 95°C and pH ranging from 1-10, while recording as many coincident chemical properties as was feasible. Polymerase chain reaction with sequence specific primers was used to screen samples for Korarchaeota 16S rRNA genes, and products were sequenced and phylogenetically analyzed. The resultant data set possibly expanded the habitat range of Korarchaeota to include temperatures as low as 40.7°C, identified novel korarchaeal phylotypes, and showed that korarchaeal phylotypes are not randomly distributed with respect to biogeography.