Beneath the Earth's surface, at a depth of about 2,600 feet (about 800 meters), scientists have discovered a thriving microbial life, mainly sulfate-consuming bacteria adapted to an environment totally devoid of oxygen.
A scientific breakthrough has established a direct link between the genetic heritage of microbes and their function, paving the way for a better understanding of their role in global processes such as the carbon cycle. The researchers focused on a species of sulfate-consuming bacteria in a deep aquifer under Death Valley, revealing that it was not only the most abundant organism but also the most active in this extreme environment.
Scientists have developed an innovative method to link genetics to the activity of anaerobic microbes, offering insights into learning more about microbial communities beneath the Earth's surface. This approach, highlighting a dominant bacteria in the Death Valley aquifer, opens new paths to understanding microbial roles in global processes.
Credit: Bigelow Laboratory for Ocean Sciences The project, funded by the NSF's EPSCoR program and conducted in collaboration with the Desert Research Institute and the University of New Hampshire, used an innovative combination of single-cell genetic sequencing and flow cytometry.
This latter technique, adapted from biomedical science, allowed for the rapid isolation of living microbes from aquifer water samples. By marking these microbes with a specific compound that lights up under the flow cytometry laser during chemical reactions, the scientists were able to measure cellular activity directly.
The findings of this study, published in the journal
Proceedings of the National Academy of Sciences, illustrate how this method can measure the activity of different organisms in these extreme environments. This marks a significant advancement in our understanding of microbial community dynamics, showing a wide range of activity levels among individual members.
The team from the Desert Research Institute extracting samples from the borehole in Death Valley.
Credit: Duane Moser, Desert Research Institute
This method has also been applied to the study of microbes in seawater, revealing that a small fraction of microorganisms is responsible for consuming the majority of the ocean's oxygen.
Researchers are now considering extending their method to study other anaerobic reactions and new environments, including sediments along the coast of Maine. A related project funded by NASA will also test this method in the deep subsurface beneath the ocean, potentially paving the way for applications on other planets.