The Epsilonproteobacteria are the most poorly characterized division within the Proteobacteria, despite ongoing attention given to the pathogens, Helicobacter and Campylobacter. The environmental importance of this group of bacteria, including their roles in the carbon, nitrogen and sulfur cycling is just beginning to be appreciated. Epsilonproteobacteria are found in a variety of sulfur-rich environments, such as caves and deep-sea hydrothermal vents. The proposed research will (1) diagnose taxonomic relationships based on DNA sequences retrieved from both environmental samples and from pure cultures, and (2) differentiate among the mechanisms that may have led to extensive epsilonproteobacterial diversity. Beyond discovery of underrepresented microbes living in natural sulfidic springs and caves, this research will address important questions regarding species diversity in terrestrial groundwater systems, controls of diversity (based on ecotype), and potential biogeochemical interactions between microbes and their habitats. Springs are intimate links to groundwater that are susceptible to negative anthropogenic activities (e.g., neglect, overuse, exploitation), and limited data have precluded a complete appreciation for how rare, or threatened, many groundwater ecosystems are. The results of this study will provide water resource managers with a better understanding of ecosystem diversity. This interdisciplinary project coincides with the establishment of the Geomicrobiology research program at LSU. Graduate and undergraduate training will be emphasized and minority participation will be encouraged through programmatic initiatives at both universities.
