Rich Microbial Biosphere Discovered Buried Deep in Chile’s Atacama Desert

Rich Microbial Biosphere Discovered Buried Deep in Chile’s Atacama Desert

A recent study has revealed a rich microbial biosphere thriving beneath the arid surface of Chile’s Atacama Desert, providing insights into extremophilic life and potential implications for astrobiology.

Depth of Microbial Biosphere:

  • Previous discoveries have identified microbial life in the Atacama Desert down to depths of 2.6 feet (80 centimeters).
  • However, a new biosphere has been found in the Yungay Valley, reaching depths of at least 13 feet (4 meters).
  • This biosphere is completely isolated from the surface, representing one of the deepest microbial habitats in Atacama soils.

Microbial Composition:

  • The newly discovered microbial community is dominated by Actinobacteria, a diverse group found in various extreme environments globally.
  • Actinobacteria were found between 6.6 feet (2 meters) and 13 feet deep.
  • Additionally, Firmicutes, resilient to high salt concentrations and anaerobic conditions, were discovered at deeper depths.


  • Researchers extracted soil samples from the Yungay Valley and isolated DNA fragments to study microbial diversity.
  • A novel method was devised to differentiate intracellular DNA from free-floating extracellular DNA, enhancing accuracy in microbial diversity studies.

Survival Mechanisms:

  • At depths where salt concentrations were too high for most microbes, a transition zone to a stable microbial community was observed.
  • Actinobacteria likely colonized river deposits around 19,000 years ago and became buried beneath playa sediments over millennia.
  • Survival mechanisms include water extraction from gypsum, a reversible process potentially releasing water in Atacama soils.

Implications for Astrobiology:

  • The Atacama Desert serves as an analog for Mars due to its extreme conditions.
  • Gypsum deposits in the Atacama Desert, similar to those on Mars, could harbor microbial life.
  • Insights from this research may aid in the search for life on Mars and other celestial bodies.

Multiple Choice Questions (MCQs):

  1. How deep is the microbial biosphere discovered in Chile’s Atacama Desert?
    • A) 2.6 feet
    • B) 6.6 feet
    • C) At least 13 feet
    • D) 4 meters
    • Answer: C) At least 13 feet
  2. Which phylum of bacteria dominates the newly discovered microbial community in the Atacama Desert?
    • A) Proteobacteria
    • B) Actinobacteria
    • C) Firmicutes
    • D) Cyanobacteria
    • Answer: B) Actinobacteria
  3. What innovative approach was used to differentiate DNA fragments in the study of microbial diversity?
    • A) DNA sequencing
    • B) Soil sampling
    • C) Intracellular DNA extraction
    • D) Free-floating DNA analysis
    • Answer: C) Intracellular DNA extraction
  4. How do microbes at deeper depths in the Atacama Desert likely survive?
    • A) Photosynthesis
    • B) Salt tolerance
    • C) Oxygen requirement
    • D) High temperatures
    • Answer: B) Salt tolerance
  5. What is the significance of gypsum deposits in the context of astrobiology?
    • A) They serve as an energy source for microbes
    • B) They indicate past water presence
    • C) They contain extraterrestrial life forms
    • D) They hinder microbial colonization
    • Answer: B) They indicate past water presence