N-182. Borup Fiord: A Unique Glacial-Sulfur Spring Environment in the Canadian High Arctic

C. Williamson, J. Spear;
Colorado Sch. of Mines, Golden, CO.

Borup Fiord Pass, on Ellesmere Island in the Canadian High Arctic, offers a unique setting for the study of a sulfur-rich, arctic environment that may be a terrestrial analog for Europa. This site is one of the few known environments on earth where sulfur-rich springs are directly associated with glacial ice creating an ecosystem of astrobiological interest. The springs discharge onto the glacial ice producing yellow mineral deposits composed of sulfur, calcite, and gypsum. Sulfur is present in three oxidation states suggesting that complex sulfur cycling, which is likely biologically mediated, is taking place at the site. Understanding microbial diversity associated with the sulfur springs at Borup Fiord will provide insight into possible modes of life that could be sustained within the ocean or ice shell of Europa. Microbial community composition of water and mineral samples collected in 2006 and 2007 has been evaluated by 16S rRNA gene sequence analysis. Clone libraries generated from samples collected at the sources of the sulfur-rich springs and from mineral deposits down-gradient of the springs’ sources were analyzed to determine the phylogenetic relationship of discovered sequences to known microbial lineages. Sequences retrieved from the sites as well as from unique cultivars showed a close phyologenetic relationship to bacterial groups including Burkholderiales, Sulfuricurvales, Sulfurovumales, Desulfobulbaceae, Desulfuromonadales, and Thiomicrospira. The identification of sulfur-metabolizing bacteria in this arctic ecosystem may indicate that sulfur utilization is responsible for sustaining life in this environment and possibly in an environment that may exist on Europa.