Researchers at Bigelow Laboratory for Ocean Sciences have developed a new method to link the genetics and function of individual microbes living deep below Earth's surface. The study, published in the Proceedings of the National Academy of Sciences, highlights how this innovative approach can help understand microbial communities' roles in global processes such as the carbon cycle.
The team utilized cutting-edge technologies to study microbes in groundwater aquifers beneath Death Valley. "Some of the organisms from this study are identical at the species level to some of the deepest life ever detected at locations around the world," said Duane Moser, an associate research professor at the Desert Research Institute. "But for the first time, because of unique single-cell genomics tools, we are able to identify active organisms at the scale of a single cell that respond to stimuli in near-real-time."
This research is part of a larger project funded by NSF's EPSCoR program called "Genomes to Phenomes," involving Bigelow Laboratory, Desert Research Institute (DRI), and University of New Hampshire. Flow cytometry was adapted from biomedical sciences to quickly sort out living microbes in water samples from Death Valley. These microbes were stained with a compound that fluoresces under laser light during certain chemical reactions.
Ali Saidi-Mehrabad noted that both projects were funded by NSF "to refine and test a suite of cutting-edge technologies." The findings suggest these methods could provide insights into microbial activity levels in extreme environments. Melody Lindsay, lead author on the paper, stated: "Previously, we had to assume that all cells were operating at the same rate, but now we can see that there is a wide range of activity levels between individual members."
Ramunas Stepanauskas expressed excitement about understanding enigmatic microbial ecosystems underground through their facility's analytical capabilities.
Duane Moser emphasized that studies like this can illuminate subsurface microbial viability and respiration status while offering potential insights into extraterrestrial life possibilities.
Ali Saidi-Mehrabad highlighted how ongoing DRI studies complement earlier research capturing temporal and spatial variations within deep continental aquifer communities over time.
Molly Devlin added that linking microbial activity measurements helps better understand key physiologies like sulfate reduction and methanogenesis: “Previously...the lack of activity measurements for suspected methanogens has led us to consider alternate origins for this methane.”
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