Browsing by Author "Taylor, William 'Peyton'"

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Relationships among geochemical processes and microbial community structure in a unique high-arsenic, sulfidic geothermal spring in Yellowstone National Park
(Montana State University - Bozeman, College of Agriculture, 2007) Taylor, William 'Peyton'; Chairperson, Graduate Committee: William P. Inskeep.
The metabolisms of chemotrophic microorganisms are linked with the geochemical transformation of redox-active chemical species and mineral precipitation-dissolution reactions in geothermal environments. The objectives of the current work were to correlate the spatial distribution of microbial populations with changes in aqueous geochemistry and mineralogy in a unique Yellowstone National Park (YNP) geothermal spring, and to cultivate thermophilic microorganisms with phylogenetic and metabolic relevance to spring conditions. The geothermal spring (hereafter referenced as Joseph's Coat Spring -JC3) contains the highest reported concentrations of arsenic, antimony and thiosulfate of any geothermal feature studied in YNP. A suite of analytical and molecular approaches including aqueous geochemical and dissolved gas analysis, solid phase characterization, energetic calculations, microscopy and 16S rRNA gene sequence distribution were utilized to correlate specific microbial populations with biogeochemical processes. Predominant geochemical changes observed within the outflow channel were disappearance of methane, dissolved sulfide and ingassing of dissolved oxygen. Oxidation of arsenite was significant within the outflow channel despite the slow ingassing rates of dissolved oxygen. Microbial 16S rRNA gene sequences were determined at locations in the source pool and within the outflow channel.