A transitory microbial habitat in the hyperarid Atacama desert
File(s)
Published version
OA Location
Author(s)
Type
Journal Article
Abstract
Traces of life are nearly ubiquitous on Earth. However, a central unresolved question is whether these traces always indicate an active microbial community or whether, in extreme environments, such as hyperarid deserts, they instead reflect just dormant or dead cells. Although microbial biomass and diversity decrease with increasing aridity in the Atacama Desert, we provide multiple lines of evidence for the presence of an at times metabolically active, microbial community in one of the driest places on Earth. We base this observation on four major lines of evidence: (i) a physico-chemical characterization of the soil habitability after an exceptional rain event, (ii) identified biomolecules indicative of potentially active cells [e.g., presence of ATP, phospholipid fatty acids (PLFAs), metabolites, and enzymatic activity], (iii) measurements of in situ replication rates of genomes of uncultivated bacteria reconstructed from selected samples, and (iv) microbial community patterns specific to soil parameters and depths. We infer that the microbial populations have undergone selection and adaptation in response to their specific soil microenvironment and in particular to the degree of aridity. Collectively, our results highlight that even the hyperarid Atacama Desert can provide a habitable environment for microorganisms that allows them to become metabolically active following an episodic increase in moisture and that once it decreases, so does the activity of the microbiota. These results have implications for the prospect of life on other planets such as Mars, which has transitioned from an earlier wetter environment to today’s extreme hyperaridity.
Date Issued
2018-03-13
Date Acceptance
2018-01-25
Citation
Proceedings of the National Academy of Sciences, 2018, 115 (11), pp.2670-2675
ISSN
0027-8424
Publisher
National Academy of Sciences
Start Page
2670
End Page
2675
Journal / Book Title
Proceedings of the National Academy of Sciences
Volume
115
Issue
11
Copyright Statement
© 2018 the Author(s). Published by PNAS. This open access article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND).
Sponsor
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council (STFC)
Grant Number
ST/N000560/1
ST/N000803/1
Subjects
Science & Technology
Multidisciplinary Sciences
Science & Technology - Other Topics
habitat
aridity
microbial activity
biomarker
Mars
DIVERSITY
DNA
VIRUSES
CHILE
NOV.
LIFE
Mars
aridity
biomarker
habitat
microbial activity
Bacteria
Biodiversity
Desert Climate
Ecosystem
Soil
Soil Microbiology
South America
Bacteria
Soil
Soil Microbiology
Ecosystem
Biodiversity
Desert Climate
South America
Publication Status
Published
Date Publish Online
2018-02-26