scholarly journals Subsurface microbial habitats in an extreme desert Mars-analogue environment

2018 ◽  
Author(s):  
Kimberley A. Warren-Rhodes ◽  
Kevin C. Lee ◽  
Stephen D.J. Archer ◽  
Nathalie Cabrol ◽  
Linda Ng-Boyle ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Bacterial Communities ◽  
Atacama Desert ◽  
Geochemical Analysis ◽  
Soluble Salts ◽  
Microbial Life ◽  
Subsurface Sediments ◽  
Sample Recovery ◽  
Osmotic Challenge

AbstractSediments in the hyper-arid core of the Atacama Desert are a terrestrial analogue to Mars regolith. Understanding the distribution and drivers of microbial life in the sediment may give critical clues on how to search for biosignatures on Mars. Here, we identify the spatial distribution of highly specialised bacterial communities in previously unexplored depth horizons of subsurface sediments. We deployed an autonomous rover in a mission-relevant Martian drilling scenario with manual sample validation. Subsurface communities were delineated by depth related to sediment moisture. Geochemical analysis indicated soluble salts and minerology that influenced water bio-availability, particularly in deeper sediments. Colonization was also patchy and uncolonized sediment was associated with indicators of extreme osmotic challenge. The study identifies linkage between biocomplexity, moisture and geochemistry in Mars-like sediments at the limit of habitability and demonstrates feasibility of the rover-mounted drill for future Mars sample recovery.

The spatial distribution of soluble salts in the surface soil of the Atacama Desert and their relationship to hyperaridity

2020 ◽  
Vol 184 ◽  
pp. 103077 ◽  
Author(s):  
Claudia Voigt ◽  
Swea Klipsch ◽  
Daniel Herwartz ◽  
Guillermo Chong ◽  
Michael Staubwasser
Keyword(s):  
Spatial Distribution ◽  
Surface Soil ◽  
Atacama Desert ◽  
Soluble Salts

scholarly journals Microbial colonization of chasmoendolithic habitats in the hyper-arid zone of the Atacama Desert

2012 ◽  
Vol 9 (11) ◽  
pp. 15603-15632
Author(s):  
J. DiRuggiero ◽  
J. Wierzchos ◽  
C. K. Robinson ◽  
T. Souterre ◽  
J. Ravel ◽  
...  
Keyword(s):  
High Throughput Sequencing ◽  
Heterotrophic Bacteria ◽  
Arid Zone ◽  
Atacama Desert ◽  
Community Diversity ◽  
Microbial Colonization ◽  
Climate Data ◽  
Microbial Life ◽  
Total Community ◽  
Diverse Community

Abstract. Efforts in searching for microbial life in the driest part of Atacama Desert, Chile, revealed a small number of lithic habitats that can be considered as environmental refuges for life. In this study, we describe for the first time chasmoendolithic colonization of fissures and cracks of rhyolite-gypsum and calcite rocks collected in the hyper-arid zone of the desert. The use of high-throughput sequencing revealed that the Atacama rock communities comprised a few dominant phylotypes and a number of less abundant taxa representing the majority of the total community diversity. The chasmoendolithic communities were dominated by Chroococcidiopsis species cyanobacteria and supported a number of novel heterotrophic bacteria. Micro-climate data and geomorphic analysis of the mineral substrates suggested higher water availability in the calcite rocks in the form of enhanced water retention in the complex network of cracks and fissures of these rocks as well as increased occurrence of liquid water in the form of dewfall. These characteristics were associated with a diverse community of phototrophic and heterotrophic bacteria in the calcite chasmoendolithic ecosystem. This study is another example of the diversity of adaptive strategies at the limit for life and illustrates that rock colonization is controlled by a complex set of factors.

scholarly journals Temperature limits to deep subseafloor life in the Nankai Trough subduction zone

Science ◽  
2020 ◽  
Vol 370 (6521) ◽  
pp. 1230-1234
Author(s):  
Verena B. Heuer ◽  
Fumio Inagaki ◽  
Yuki Morono ◽  
Yusuke Kubo ◽  
Arthur J. Spivack ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Marine Sediment ◽  
Nankai Trough ◽  
Microbial Populations ◽  
Vegetative Cells ◽  
Microbial Life ◽  
Sediment Volume ◽  
Subsurface Sediments ◽  
Cell Concentrations ◽  
Deep Subseafloor

Microorganisms in marine subsurface sediments substantially contribute to global biomass. Sediments warmer than 40°C account for roughly half the marine sediment volume, but the processes mediated by microbial populations in these hard-to-access environments are poorly understood. We investigated microbial life in up to 1.2-kilometer-deep and up to 120°C hot sediments in the Nankai Trough subduction zone. Above 45°C, concentrations of vegetative cells drop two orders of magnitude and endospores become more than 6000 times more abundant than vegetative cells. Methane is biologically produced and oxidized until sediments reach 80° to 85°C. In 100° to 120°C sediments, isotopic evidence and increased cell concentrations demonstrate the activity of acetate-degrading hyperthermophiles. Above 45°C, populated zones alternate with zones up to 192 meters thick where microbes were undetectable.

scholarly journals Spatial distribution of marine airborne bacterial communities

2015 ◽  
Vol 4 (3) ◽  
pp. 475-490 ◽  
Author(s):  
Jasmin S. Seifried ◽  
Antje Wichels ◽  
Gunnar Gerdts
Keyword(s):  
Spatial Distribution ◽  
Bacterial Communities

scholarly journals The Atacama Desert in Northern Chile as an Analog Model of Mars

2022 ◽  
Vol 8 ◽  
Author(s):  
Armando Azua-Bustos ◽  
Carlos González-Silva ◽  
Alberto G. Fairén
Keyword(s):  
Atacama Desert ◽  
Analog Model ◽  
Patchy Distribution ◽  
Microbial Life ◽  
Environmental Extremes ◽  
Life On Mars ◽  
Domains Of Life ◽  
Mars Analog ◽  
The Impact

The Atacama Desert is by far the driest and oldest desert on Earth, showing a unique combination of environmental extremes (extreme dryness, the highest UV radiation levels on Earth, and highly saline and oxidizing soils), explaining why the Atacama has been largely investigated as a Mars analog model for almost 20 years. Based on the source and the amount of water available for life and its analogy with Mars, two ecosystems are of interest in the Atacama: its Coastal Range and the much drier hyperarid core, which we here review in detail. Members of the three domains of life have been found across these ecosystems living at the limit of habitability, suggesting the potential dry limits for each domain and also unveiling the highly patchy distribution of microbial life in its most extreme regions. The thorough study of the Atacama has allowed us to understand how life has adapted to its extreme conditions, the specific habitats that life occupies in each case (thus suggesting the most likely places in which to search for evidence for life on Mars), and the number of biosignatures detected across this desert. Also, the characterization of west-to-east transects across this desert has shown to be of significant value to understand the potential adaptations that Martian microorganisms may have followed in an ever-drying planet. All of this explains why the Atacama is actively used as the testing ground of the technologies (detection instruments, rovers, etc.) that were sent and will be sent to Mars. We also highlight the need to better inform the exact locations of the sites studied to understand general trends, the need to identify the true native microbial species of the Atacama, and the impact of climate change on the most arid and most Martian desert of Earth.

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