Life-Forms Found Deep in World’s Oldest Groundwater

The single-celled organisms don’t need oxygen or sunlight because they breathe sulfur compounds.
Loukia Papadopoulos

Deep in the depths of Canada's Kidd Mine, researchers have stumbled on a strange life-form. These bacteria live 2.4 kilometers below the surface, in perpetual darkness and in the world's oldest groundwater.

Single-celled organisms

The discovery was made last July by a team led by University of Toronto geologist Barbara Sherwood Lollar. The single-celled organisms don’t need oxygen or sunlight because they breathe sulfur compounds, living off chemicals in the surrounding rock.


The novel findings were published in a new paper in Geomicrobiology Journal. “To me, the most exciting part isn’t about finding yet another environment where we previously thought life couldn’t exist. It’s about changing the way we think about investigating novel environments to focus on using techniques across many disciplines in concert with each other,” said first author Garnet Lollar of the University of Toronto, Canada.

The new findings confirm the results of a previous study by this same group where they speculated that sulfate-reducing microbes had been active in these fluids over geologic timescales. Now, the new study lays the groundwork to identifying the microbes in these ancient waters.

“The Deep Carbon Observatory (DCO) was very catalytic in this and supported us in this idea of bringing together all kinds of people so that multiple teams could take samples and compare and contrast their final results,” said Lollar. Currently, DCO researchers are sequencing the genomes of the individual microbes.

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Follow the water

They are also sequencing the metagenome, which is all the genomes of organisms in the water. The investigation has been said to borrow the “follow the water” mantra.

This mantra has been known to guide the search for life on other planets. By studying the data from the water geochemistry, mineralogy, and isotopic signatures at a site, scientists can deduce how the microbial community gains food and energy.

Kidd Creek Observatory can also serve as an analog for other planets by showing what types of geology and chemistry have the potential to support life. It can be used as a basis to direct future searches for extraterrestrial life. 

However, Lollar is more focused on what there is still left to explore here on Earth. “There are fundamental principles on which the planet operates that we’re still just beginning to figure out,” she said. “There are still amazing discoveries to be made.”

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