Evidence of a microbial community associated with rock varnish at Yungay, Atacama Desert, Chile

2008 ◽  
Vol 113 (G4) ◽  
Author(s):  
Kimberly R. Kuhlman ◽  
Parth Venkat ◽  
Myron T. La Duc ◽  
Gregory M. Kuhlman ◽  
Christopher P. McKay
Keyword(s):  
Microbial Community ◽  
Atacama Desert ◽  
Rock Varnish

scholarly journals Physicochemical Parameters Affecting the Distribution and Diversity of the Water Column Microbial Community in the High-Altitude Andean Lake System of La Brava and La Punta

2020 ◽  
Vol 8 (8) ◽  
pp. 1181
Author(s):  
Reynaldo Núñez Salazar ◽  
Carlos Aguirre ◽  
Jorge Soto ◽  
Pamela Salinas ◽  
Carlos Salinas ◽  
...  
Keyword(s):  
Microbial Community ◽  
High Altitude ◽  
Water Column ◽  
Physicochemical Parameters ◽  
Microbial Community Composition ◽  
Atacama Desert ◽  
Rrna Gene ◽  
16S Rrna Gene Analysis ◽  
Lake System ◽  
Influence Of Water

Due to the low incidence of precipitation attributed to climate change, many high-altitude Andean lakes (HAALs) and lagoons distributed along the central Andes in South America may soon disappear. This includes La Brava–La Punta, a brackish lake system located south of the Salar de Atacama within a hyper-arid and halophytic biome in the Atacama Desert. Variations in the physicochemical parameters of the water column can induce changes in microbial community composition, which we aimed to determine. Sixteen sampling points across La Brava–La Punta were studied to assess the influence of water physicochemical properties on the aquatic microbial community, determined via 16S rRNA gene analysis. Parameters such as pH and the concentrations of silica, magnesium, calcium, salinity, and dissolved oxygen showed a more homogenous pattern in La Punta samples, whereas those from La Brava had greater variability; pH and total silica were significantly different between La Brava and La Punta. The predominant phyla were Proteobacteria, Bacteroidetes, Actinobacteria, and Verrucomicrobia. The genera Psychroflexus (36.85%), Thiomicrospira (12.48%), and Pseudomonas (7.81%) were more abundant in La Brava, while Pseudospirillum (20.73%) and Roseovarius (17.20%) were more abundant in La Punta. Among the parameters, pH was the only statistically significant factor influencing the diversity within La Brava lake. These results complement the known microbial diversity and composition in the HAALs of the Atacama Desert.

scholarly journals Fundamental drivers for endolithic microbial community assemblies in the hyperarid Atacama Desert

2018 ◽  
Vol 20 (5) ◽  
pp. 1765-1781 ◽  
Author(s):  
Victoria Meslier ◽  
M. Cristina Casero ◽  
Micah Dailey ◽  
Jacek Wierzchos ◽  
Carmen Ascaso ◽  
...  
Keyword(s):  
Microbial Community ◽  
Atacama Desert

scholarly journals Spatial and Temporal Variability of Microbial Communities and Salt Distributions Across an Aridity Gradient Before and After Heavy Rains in the Atacama Desert

2020 ◽  
Author(s):  
Jianxun Shen ◽  
Timothy Shirey ◽  
Adam Wyness ◽  
Mark Claire ◽  
Aubrey Zerkle
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Microbial Community Composition ◽  
Atacama Desert ◽  
Spatial And Temporal Variability ◽  
Rainfall Events ◽  
Aridity Gradient ◽  
Before And After ◽  
Mars Analog ◽  
Heavy Rainfalls

Over the past 150 million years, the hyperarid core of the Atacama Desert has been transformed by geologic and atmospheric conditions into one of the most unique and inhospitable landscapes on the planet. This makes it an ideal Mars analog that has been explored for decades as preliminary studies on the space life discovery. However, two heavy rainfalls that occurred in the Atacama in 2015 and 2017 provide a unique opportunity to study the response of resident extremophiles to rapid environmental change associated with excessive water and salt shock. Here we combine geochemical analyses with molecular biology to study the variations in salts and microbial communities along an aridity gradient, and to examine the reshuffling of hyperarid microbiomes before and after the two rainfall events. Analysis of microbial community composition revealed that soils within the southern desert were consistently dominated by Actinobacteria, Proteobacteria, Acidobacteria, Planctomycetes, Chloroflexi, Bacteroidetes, Gemmatimonadetes, and Verrucomicrobia; soils within the hyperarid sites were dominated by Aquificae and Deinococcus-Thermus before heavy rainfalls, while these organisms almost totally diminished after rainfall, and the hyperarid microbial consortia and metabolisms transformed to a more southern desert pattern along with increased biodiversity. Salts at the shallow subsurface were dissolved and leached down to a deeper layer, both benefitting and challenging indigenous microorganisms with the excessive input of water and ions. Microbial viability was found to change with aridity and rainfall events but correlated with elevation, pH, conductivity, chloride, nitrate, sulfate, and soil organic matters (SOM). Metagenomic functional pathways related to stressor responses also increased in post-rainfall hyperarid soils. Our findings contribute to the primary goal of Atacama Mars analog research for understanding the microbial community structure and adaptations: this study sheds light on the structure of xerophilic, halophilic, and radioresistant microbiomes in hyperarid environments, and their response to changes in water availability.

scholarly journals Transitory microbial habitat in the hyperarid Atacama Desert

2018 ◽  
Vol 115 (11) ◽  
pp. 2670-2675 ◽  
Author(s):  
Dirk Schulze-Makuch ◽  
Dirk Wagner ◽  
Samuel P. Kounaves ◽  
Kai Mangelsdorf ◽  
Kevin G. Devine ◽  
...  
Keyword(s):  
Microbial Community ◽  
Extreme Environments ◽  
Atacama Desert ◽  
Chemical Characterization ◽  
Soil Parameters ◽  
Rain Event ◽  
Community Patterns ◽  
Microbial Habitat ◽  
Lines Of Evidence ◽  
Active Microbial Community

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.

scholarly journals Inhabited subsurface wet smectites in the hyperarid core of the Atacama Desert as an analog for the search for life on Mars

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Armando Azua-Bustos ◽  
Alberto G. Fairén ◽  
Carlos González Silva ◽  
Daniel Carrizo ◽  
Miguel Ángel Fernández-Martínez ◽  
...  
Keyword(s):  
Microbial Community ◽  
Atacama Desert ◽  
Martian Surface ◽  
Microbial Life ◽  
Clay Deposits ◽  
Life On Mars ◽  
Subsurface Layers ◽  
Active Bacteria ◽  
Halophilic Species ◽  
Diverse Microbial Community

Abstract The modern Martian surface is unlikely to be habitable due to its extreme aridity among other environmental factors. This is the reason why the hyperarid core of the Atacama Desert has been studied as an analog for the habitability of Mars for more than 50 years. Here we report a layer enriched in smectites located just 30 cm below the surface of the hyperarid core of the Atacama. We discovered the clay-rich layer to be wet (a phenomenon never observed before in this region), keeping a high and constant relative humidity of 78% (aw 0.780), and completely isolated from the changing and extremely dry subaerial conditions characteristic of the Atacama. The smectite-rich layer is inhabited by at least 30 halophilic species of metabolically active bacteria and archaea, unveiling a previously unreported habitat for microbial life under the surface of the driest place on Earth. The discovery of a diverse microbial community in smectite-rich subsurface layers in the hyperarid core of the Atacama, and the collection of biosignatures we have identified within the clays, suggest that similar shallow clay deposits on Mars may contain biosignatures easily reachable by current rovers and landers.

scholarly journals Functional analysis of the archaea, bacteria, and viruses from a halite endolithic microbial community

2015 ◽  
Author(s):  
Alexander Crits-Christoph ◽  
Diego R Gelsinger ◽  
Bing Ma ◽  
Jacek Wierzchos ◽  
Jacques Ravel ◽  
...  
Keyword(s):  
Functional Analysis ◽  
Microbial Community ◽  
Water Availability ◽  
Viral Genome ◽  
Co2 Fixation ◽  
Genome Structure ◽  
Atacama Desert ◽  
Autotrophic Co2 Fixation ◽  
Microbial Ecosystems ◽  
Osmotic Balance

Halite endoliths in the Atacama Desert represent one of the most extreme microbial ecosystems on Earth. Here we sequenced and characterized a shotgun metagenome from halite nodules collected in Salar Grande, Chile. The community is dominated by archaea and functional analysis attributed most of the autotrophic CO2 fixation to a unique cyanobacterium. The assembled 1.1 Mbp genome of a novel nanohaloarchaeon, Candidatus Nanopetramus SG9, revealed a photoheterotrophic life style and a low median isoelectric point (pI) for all predicted proteins, suggesting a "salt-in" strategy for osmotic balance. Predicted proteins of the algae identified in the community also had pI distributions similar to "salt-in" strategists. The Nanopetramus genome contained a unique CRISPR/Cas system with a spacer that matched a partial viral genome from the metagenome. A combination of reference-independent methods identified over 30 complete or near complete viral or proviral genomes with diverse genome structure, genome size, gene content, and hosts. Putative hosts included Halobacteriaceae, Nanohaloarchaea, and Cyanobacteria. Despite the dependence of the halite community on deliquescence for liquid water availability, this study exposed an ecosystem spanning three phylogenetic domains, containing a large diversity of viruses, and a predominant salt-in strategy to balance the high osmotic pressure of the environment.

scholarly journals Diversity of Microorganisms within Rock Varnish in the Whipple Mountains, California

2006 ◽  
Vol 72 (2) ◽  
pp. 1708-1715 ◽  
Author(s):  
K. R. Kuhlman ◽  
W. G. Fusco ◽  
M. T. La Duc ◽  
L. B. Allenbach ◽  
C. L. Ball ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Microbial Community ◽  
Phospholipid Fatty Acids ◽  
Microbial Colonization ◽  
Rrna Gene ◽  
Rock Varnish ◽  
Gene Libraries ◽  
Whipple Mountains

ABSTRACT Rock varnish from Arizona's Whipple Mountains harbors a microbial community containing about 108 microorganisms g−1 of varnish. Analyses of varnish phospholipid fatty acids and rRNA gene libraries reveal a community comprised of mostly Proteobacteria but also including Actinobacteria, eukaryota, and a few members of the Archaea. Rock varnish represents a significant niche for microbial colonization.

scholarly journals Halophilic microbial community compositional shift after a rare rainfall in the Atacama Desert

2019 ◽  
Vol 13 (11) ◽  
pp. 2737-2749 ◽  
Author(s):  
Gherman Uritskiy ◽  
Samantha Getsin ◽  
Adam Munn ◽  
Benito Gomez-Silva ◽  
Alfonso Davila ◽  
...  
Keyword(s):  
Microbial Community ◽  
Atacama Desert
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