Microbial Diversity and Function in Shallow Subsurface Sediment and Oceanic Lithosphere of the Atlantis Massif
Jacqueline Goordial, Timothy D’Angelo, Jessica Labonté, Nicole Poulton, Julia M. Brown, Ramūnas Stepanauskas, Gretchen L. Früh‐Green, Beth N. Orcutt
Abstract
The subsurface rock beneath the ocean is one of the largest biospheres on Earth, and microorganisms within influence global-scale nutrient cycles. This biosphere is difficult to study, in part due to the low concentrations of microorganisms that inhabit the vast volume of the marine lithosphere. In spite of the global significance of this biosphere, little is currently known about the microbial ecology of such rock-associated microorganisms. This study describes the identity and genomic potential of microorganisms in the subsurface rock and sediment at the Atlantis Massif, an underwater mountain near the Mid-Atlantic Ridge. To enable our analyses, fluorescence-activated cell sorting (FACS) was used as a means to concentrate cells from low biomass environmental samples for genomic analyses. We found distinct rock-associated microorganisms and found that the capacity for microorganisms to utilize organic carbon was the most prevalent form of carbon cycling. We additionally identified a potential role for carbon monoxide metabolism in the subsurface.