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Jasmine Berg
Washington University in St. Louis, Department of Earth and Planetary Sciences
Associate Professor Jan Amend
Abstract
Hydrothermal vent systems have been implicated in recent theories about the origins of life, and therefore the study of such extreme environments may also provide clues about the possibility of life forms existing on other planets. This study features a characterization of the microbial communities at two shallow-sea hydrothermal vent sites near Sicily, Italy. Both sites are characterized by white mats of elemental sulfur precipitate, anoxic and hypersaline waters, and CO2 and H2S degassing, but differ in local chemistry and temperature. Fluorescence microscopy revealed an abundance of cells which appeared to be morphologically distinct between sites. Sequencing of 16S rDNA revealed a greater diversity of bacteria than archaea at both sites and a greater total microbial diversity at the lower temperature site. The bacteria are dominated by ?-proteobacteria and bacteroidetes and include both sulfur-oxidizing and sulfur-reducing metabolisms; the archaea are predominantly euryarchaeota. These findings indicate that the microbial metabolisms are related to sulfur cycling in the environment and may provide insight for tracing the existence of life from the biological impacts on the environment. Future work will include quantification of bacteria and archaea as well as mapping phylogenetic trees in order to understand community structure and relationships between organisms and the environment.
Jasmine Berg is a junior from Los Altos, California currently studying both environmental studies-geosciences and Spanish at Washington University in St. Louis. She hopes to continue research in the field of geosciences in graduate school.
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