Epsilonproteobacteria : Deep Sea Hydrothermal Vents and Beyond

 

We have two projects that involve investigating the Epsilonproteobacteria.

1) Novel Nitrogen Pathways in Epsilonproteobacteria. Nitrogen is a key nutrient that all living beings need to grow. Most transformations of nitrogen in the Earth's surface are catalyzed by microbes including the interconversion between different fixed nitrogen species. The preferred nitrogen species for growth is ammonium, often a limiting nutrient in ecosystems. This project details a new means by which certain microbes "breathe" or respire nitrate and produce ammonium to conserve energy. Nitrate respiration is not new per se, but the mechanism used by the primary model bacterium for this study, Nautilia profundicola, is novel and may be important for it to making a living at deep-sea hydrothermal vents. Relatives of N. profundicola are also being studied that carry the genes encoding the same pathway. Specifically we study Campylobacter curvus, which has been isolated the oral cavity of humans. This project uses high-throughput transcriptomics and combine it with more traditional physiological approaches to characterize this novel nitrate reduction pathway in these two bacteria.

2) Epsilonproteobacteria from terrestrial environments. In collaboration with Annette Engel (UTK), we are examining the diversity and function of this important chemolithoautotrophic group of bacteria in the understudied, but more accessible terrestrial karst environments.  We have geochemical, diversity and metagenomic data that indicates this group of bacteria are keystone species in these environments.

 

Study Sites 

 

Laboratory, using bacteria isolated from Deep Sea Hydrothermal Vents and the oral cavity of Humans; Global sulfidic caves and springs 

 

Lab Participants

 

Marco Valera, Hunter Seiders, Carly Dameron, Kevin Ketner 

 

Presentations/Papers

 

Rossmassler et al, 2016, Dameron et al., ASM, 2014, Hanson et al., 2013,

Campbell et al., 2013, Campbell et al., 2009

 

 

Funding

 

NSF, Collaborative Research: Do diverse members of the Epsilonproteobacteria employ a novel nitrate reduction pathway?, PI with co-PIs Tom Hanson, University of Delaware and Martin Klotz, UNC Charlotte