An abundance of microbial life has been found in Chile’s
The Atacama is the driest nonpolar desert – but not the
While higher life forms are almost entirely absent, bacteria are known to inhabit the bone-dry, salty, and sulfate-rich soil – even at great depths. In a previously unexplored underground habitat in the Yungay region of the desert, researchers have found a surprisingly diverse community of microbes likely completely isolated from life at the surface.
Previous research has focused mostly on soil at the surface, meaning that, until now, what lies deep underground has been a bit of a mystery. “To our knowledge, this represents the deepest microbial survey and discovery of microbial life in Atacama soils to this day,” the team write in a new study describing their findings.
Digging down into the hyper-arid soil to a depth of 4.2 meters (13.8 feet), the researchers took regular soil samples before using a new method of molecular DNA analysis to isolate only
Doing so has enabled them to uncover a hidden biosphere that is helping to expand our understanding of biodiversity in the Atacama Desert and beyond.
In the upper 80 centimeters (31.5 inches) of soil, the team found that communities were dominated by Firmicutes (or Bacillota) – a phylum of bacteria that includes
But below 200 centimeters, microbes reemerge. Here, a different microbial population was observed, dominated by Actinobacteria. The authors suggest that this community might have colonized the soil 19,000 years ago, before being buried by further soil deposits. They could, the team hypothesize, extend much deeper than 4.2 meters and may “represent the upper extent of a deep biosphere underneath hyperarid desert soils”.
To survive at such depths, the bacteria may rely on the mineral
“The exploration of gypsum-associated subsurface environments in the Atacama Desert has direct relevance to astrobiology, since gypsum deposits on
“Thus, the data from this study is helping us to understand if and how life may exist in similar environments on other planets or moons across our Solar System.”
The study is published in the journal