The overall objective of this project is to examine the specific nature of the microbial population within deep sea subsurface environments. This project has four components: 1) to characterize the biodiversity that exists in subseafloor environments and determine the nature of constituent microbial physiologies; 2) to determine the chemical bioenergetics of the subsurface, specifically the carbon, nitrogen, sulfur, and phosphorous species of microbial relevance that are prevalent in subsurface environments; 3) to determine the intracellular bioenergetics of model hetertrophic hyperthermophiles and those newly-isolated from the subsurface, including their primary energy currency and electron carriers, and their organic and inorganic `signatures`; and 4) to characterize the extracellular bioenergetics of known and newly-isolated hyperthermophiles in subsurface environments, including electron donors and acceptors, inorganic nutrients, and their capacity to produce exocellular polymers, to inhabit biofilms, and to exist as consortia. The results of this project are to serve as a paradigm for the characterization of extraterrestrial ecosystems and potential life forms therein.
