Microbial diversity in steam vent sublimates

Benson, Courtney

Fumaroles, commonly called steam vents, are ubiquitous features of geothermal habitats. Several recent studies have found microorganisms in steam condensed from fumaroles. Studies have been attempted to discover the microbial diversity in fumarole steam sediments, however, little is still known. In the present study, steam sublimates (deposits left by steam) collected from fumarole vents and caves were analyzed for archaeal and bacterial DNA from Hawaii Volcanoes National Park, Yellowstone National Park, and Lassen Volcanic National Park. Environmental sites were classified by X-ray microanalysis as non-sulfur, sulfur and iron. We isolated archaeal and bacterial DNA by culture-dependent and independent methods. We only were able to extract environmental DNA from half of the sample sites, demonstrating the difficulty of environmental DNA extractions. In contrast, we cultured Archaea and Bacteria from the greater majority of the sample locations. Cultured organisms all stained positive for dsDNA by DAPI. Phylogenetic analysis confirmed the types of Archaea found were Sulfolobus species or other Sulfolobales, as well as unknown Archaea, demonstrating little diversity among archaeal communities in fumaroles. The Bacteria found were substantially diverse, and previously unknown. The diversity found in fumarole steam sublimates is revealed in this manuscript.

Microbial diversity in steam vent sublimates

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