Project description from C-DEBI:
The microbial biosphere in serpentinizing subseafloor rocks is globally significant. Tantalizing evidence from studies of the Lost City Hydrothermal Field and continental ophiolites indicates that hydrogendriven microbial metabolisms prevails under the highly reducing, high pH conditions that characterize these environments. Interest in these processes is evident from an upcoming cruise to the Atlantis Massif in Fall 2015 to obtain drill cores in the vicinity of the Lost City Hydrothermal Field (IODP Expedition #357; both PIs were proponents of the IODP proposal and have applied as shipboard scientists). The PIs and colleagues have made headway over the last decade in identifying the key organisms and metabolisms present at the LCHF, and in constraining the sources and fates of carbon compounds. The linkages between geology and biology remain enigmatic, however, because of the precipitation of inorganic carbon at high pHs and overlapping biogenic and abiogenic carbon sources. We propose here to investigate the influence of free energy availability by sulfate reduction in resource utilization and carbon flow by model alkaliphilic prokaryotes. The laboratory approach using a model system will inform shipboard experiments with fresh samples from the AM, and the potential characterization of new organisms from serpentinizing terrains.

This project was funded by a C-DEBI Research Grant