A new study supported by the NASA Astrobiology Institute and the Astrobiology program is shedding light on microbial communities that live in low-temperature fluids just beneath the ocean crust. The largest aquifer system on Earth exists beneath the crust at the bottom of our planet’s oceans, yet life in this remote environment has remained relatively unexplored for decades. By drilling into the ocean floor, scientists retrieved low-temperature (<100°C) fluids from the environment. In the samples they found evidence of sulfate reducing microbes over a range of temperatures.

The results suggest that sulfate reducing microbes could be responsible for the removal of organic matter in fluids within the upper oceanic crust, and this might have a measurable impact on the biogeochemical cycling of carbon on Earth.

The paper, “Activity and phylogenetic diversity of sulfate-reducing microorganisms in low-temperature subsurface fluids within the upper oceanic crust,” was published in the journal Frontiers in Microbiology.