scholarly journals Microbial colonization of halite from the hyper-arid Atacama Desert studied by Raman spectroscopy

2010 ◽  
Vol 368 (1922) ◽  
pp. 3205-3221 ◽  
Author(s):  
P. Vítek ◽  
H. G. M. Edwards ◽  
J. Jehlička ◽  
C. Ascaso ◽  
A. De Los Ríos ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Atacama Desert ◽  
Microbial Colonization ◽  
Microbial Life ◽  
Spectral Signatures ◽  
Arid Conditions ◽  
Life On Mars ◽  
Moisture Conditions ◽  
Micro Organisms ◽  
Non Destructive

The hyper-arid core of the Atacama Desert (Chile) is the driest place on Earth and is considered a close analogue to the extremely arid conditions on the surface of Mars. Microbial life is very rare in soils of this hyper-arid region, and autotrophic micro-organisms are virtually absent. Instead, photosynthetic micro-organisms have successfully colonized the interior of halite crusts, which are widespread in the Atacama Desert. These endoevaporitic colonies are an example of life that has adapted to the extreme dryness by colonizing the interior of rocks that provide enhanced moisture conditions. As such, these colonies represent a novel example of potential life on Mars. Here, we present non-destructive Raman spectroscopical identification of these colonies and their organic remnants. Spectral signatures revealed the presence of UV-protective biomolecules as well as light-harvesting pigments pointing to photosynthetic activity. Compounds of biogenic origin identified within these rocks differed depending on the origins of specimens from particular areas in the desert, with differing environmental conditions. Our results also demonstrate the capability of Raman spectroscopy to identify biomarkers within rocks that have a strong astrobiological potential.

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 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.

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 Surface mineral crusts: a potential strategy for sampling for evidence of life on Mars

2018 ◽  
Vol 18 (2) ◽  
pp. 91-101 ◽  
Author(s):  
Connor Brolly ◽  
John Parnell ◽  
Stephen Bowden
Keyword(s):  
Isotope Composition ◽  
High Arctic ◽  
Gas Chromatography Mass Spectrometry ◽  
Impact Structure ◽  
Microbial Life ◽  
Spectral Signatures ◽  
Biomarker Analysis ◽  
Life On Mars ◽  
Potential Strategy ◽  
Surface Mineral

AbstractSurface mineral crusts on Earth are highly diverse and usually, contain microbial life. Crusts constitute an attractive target to search for life: they require water for their formation, they efficiently entrap organic matter and are relatively easy to sample and process. They hold a record of life in the form of microbial remains, biomolecules and carbon isotope composition. A miniaturized Raman spectrometer is included in the ExoMars 2020 payload as it is sensitive to a range of photosynthetic pigments. Samples from the Haughton Impact Structure, Canadian High Arctic and others, shows the preservation of pigments in a range of crust types, especially supra-permafrost carbonate crusts and cryptogamic crusts. The Raman spectral signatures of these crusts are shown along with biomarker analysis to showcase these techniques prior to the ExoMars 2020 mission. Carotenoids and other photoprotective microbial pigments are identified in the Haughton surface crusts using Raman spectroscopy. Gas chromatography-mass spectrometry analyses show a distribution of fatty acids which are most likely from a cyanobacterial source. The successful demonstration of these analyses in the Haughton Impact structure shows the biosignature of surface mineral crusts can be easily extracted and provides an excellent target for sampling evidence of life on Mars.

Microbial colonization of Ca-sulfate crusts in the hyperarid core of the Atacama Desert: implications for the search for life on Mars

Geobiology ◽  
2010 ◽  
Vol 9 (1) ◽  
pp. 44-60 ◽  
Author(s):  
J. WIERZCHOS ◽  
B. CÁMARA ◽  
A. DE LOS RÍOS ◽  
A. F. DAVILA ◽  
I. M. SÁNCHEZ ALMAZO ◽  
...  
Keyword(s):  
Atacama Desert ◽  
Microbial Colonization ◽  
Life On Mars

Optical Diagnostics of Microstructures Fabricated Using Quantum Well Intermixing

1999 ◽  
Vol 607 ◽  
Author(s):  
A. Saher Helmy ◽  
A.C. Bryce ◽  
C.N. Ironside ◽  
J.S. Aitchison ◽  
J.H. Marsh ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Quantum Well ◽  
Spatial Resolution ◽  
Optical Diagnostics ◽  
Complete Suppression ◽  
Quantum Well Intermixing ◽  
Spatially Resolved ◽  
Non Destructive ◽  
Insight Into ◽  
Free Vacancy

AbstractIn this paper we shall discuss techniques for accurate, non-destructive, optical characterisation of structures fabricated using quantum well intermixing (QWI). Spatially resolved photoluminescence and Raman spectroscopy were used to characterise the lateral bandgap profiles produced by impurity free vacancy disordering (IFVD) technology. Different features were used to examine the spatial resolution of the intermixing process. Features include 1:1 gratings as well as isolated stripes. From the measurements, the spatial selectivity of IFVD could be identified, and was found to be ∼4.5 μm, in contrast with the spatial resolution of the process of sputtering induced intermixing, which was found to be ∼2.5 μm. In addition, PL measurements on 1:1 gratings fabricated using IFVD show almost complete suppression of intermixing dielectric cap gratings with periods less than 10 microns. Finally, some insight into the limitations and merits of PL and Raman for the precision characterisation of QWI will be presented.

Ignimbrite as a substrate for endolithic life in the hyper-arid Atacama Desert: Implications for the search for life on Mars

Icarus ◽  
2013 ◽  
Vol 224 (2) ◽  
pp. 334-346 ◽  
Author(s):  
Jacek Wierzchos ◽  
Alfonso F. Davila ◽  
Octavio Artieda ◽  
Beatriz Cámara-Gallego ◽  
Asunción de los Ríos ◽  
...  
Keyword(s):  
Atacama Desert ◽  
Life On Mars

CHANGES IN THE HYDROTHERMAL COEFFICIENT AND IN THE FREQUENCY OF EXTREME HUMIDIFICATION CONDITIONS ON THE TERRITORY OF BELARUS DURING CLIMATE WARMING

2020 ◽  
pp. 5-18
Author(s):  
Yuliya A. Brovka ◽  
Ivan V. Buyakov
Keyword(s):  
Climate Warming ◽  
Growing Season ◽  
Northern Region ◽  
Meteorological Station ◽  
Spatial Change ◽  
Hydrothermal Coefficient ◽  
Arid Conditions ◽  
Moisture Supply ◽  
Moisture Conditions ◽  
Heat And Moisture

It is important to study the heat and moisture supply of the territory under climate warming conditions in Belarus since 1989, as well as changes in the occurrence frequency of extreme moisture conditions. The features of the spatial change in the averaged hydrothermal coefficient (HTC) for the period of climate warming (1989–2019) and the colder period preceding it (1960–1988) in the months of the growing season were revealed based on the maps constructed by interpolation. A decrease in the aridity of conditions in May and September in the southeast and east of the country, an increase in aridity in June and August (especially in the southern regions), an increase in the area with excessive moisture in July and its decrease in September were defined. The article shows the features of changes in the frequency of droughts (HTC ≤ 0,7), less arid conditions (HTC = 0,71–1,0) and excessive moisture (HTC > 1,6) from May to September in 1989–2019, according to compared with the period 1960–1988. It was found that during the period of climate warming from May to September, there is a significant increase in the droughts frequency at meteorological stations in various regions of Belarus. A decrease in the number of years with drought in May and June is observed at several eastern and southern meteorological stations, in August – at the Zhitkovichi meteorological station, in September – at the Kostyukovichi meteorological station. The frequency of arid conditions in May, July and September decreases at many meteorological stations, and its changes are characterized by territorial heterogeneity. An increase in the number of years with less arid conditions is observed in most of Belarus in June and August. A significant increase in the frequency of excessive moisture was noted in July in most of the territory of Belarus, in May – in some regions. A decrease in the frequency of excessive moisture is observed at many meteorological stations in June and August; the number of years with excessive moisture increases only in the northern region. Spatial heterogeneity and less pronounced changes in the frequency of excessive moisture are noted in September.

Development of Deep Learning Algorithms to Discriminate Giant Cell Tumor of Bone from Adjacent Normal Tissues by Confocal Raman Spectroscopy

The Analyst ◽  
2022 ◽  
Author(s):  
Carol PY Lau ◽  
Wenao Ma ◽  
Kwan Yau Law ◽  
Maribel Lacambra ◽  
Kwok Chuen Wong ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Giant Cell Tumor ◽  
Giant Cell ◽  
Chemical Structure ◽  
Cell Tumor ◽  
Confocal Raman Spectroscopy ◽  
Normal Tissues ◽  
Analysis Technique ◽  
Destructive Analysis ◽  
Non Destructive

Raman spectroscopy is a non-destructive analysis technique that provides detailed information about the chemical structure of the tumor. Raman spectra of 52 giant cell tumor of bone (GCTB), and 21...

scholarly journals Raman spectroscopy as a tool for ecology and evolution

2017 ◽  
Vol 14 (131) ◽  
pp. 20170174 ◽  
Author(s):  
Arno Germond ◽  
Vipin Kumar ◽  
Taro Ichimura ◽  
Jerome Moreau ◽  
Chikara Furusawa ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Low Cost ◽  
Biological Systems ◽  
Spectral Information ◽  
Selective Pressures ◽  
Biological Features ◽  
Microscopy Technique ◽  
Pragmatic Aspects ◽  
Non Destructive

Scientists are always on the lookout for new modalities of information which could reveal new biological features that are useful for deciphering the complexity of biological systems. Here, we introduce Raman spectroscopy as a prime candidate for ecology and evolution. To encourage the integration of this microscopy technique in the field of ecology and evolution, it is crucial to discuss first how Raman spectroscopy fits within the conceptual, technical and pragmatic considerations of ecology and evolution. In this paper, we show that the spectral information holds reliable indicators of intra- and interspecies variations, which can be related to the environment, selective pressures and fitness. Moreover, we show how the technical and pragmatic aspects of this modality (non-destructive, non-labelling, speed, relative low cost, etc.) enable it to be combined with more conventional methodologies. With this paper, we hope to open new avenues of research and extend the scope of available methodologies used in ecology and evolution.

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