Examinando por Autor "Carrizo, D."

Mostrando 1 - 13 de 13

Restringido
Centennial glacier retreat increases sedimentation and eutrophication in Subantarctic periglacial lakes: A study case of Lake Uruguay
(Elsevier BV, 2021-02-01) García Rodríguez, F.; Piccini, C.; Carrizo, D.; Sánchez García, L.; Pérez, L.; Crisci, C.; Oaquim, A. B. J.; Evangelista, H.; Soutullo, A.; Azcune, G.; Lüning, S.; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Sánchez García, L. [0000-0002-7444-1242]; Azcune, G. [0000-0003-3016-9352]
High resolution XRF scanning documented inter-annual paleolimnological changes of a Subantarctic periglacial lake, during a process of centennial glacier retreat in King George Island, Antarctica. Two major paleoenvironmental stages were inferred from the combined analysis of elemental, molecular and isotopic biomarkers, with a boundary or transition set at about 3200 yr BP. The first stage was characterized by a relatively low allochthonous organic content, reduced productivity and nitrogen levels. Such paleoenvironmental conditions are interpreted as a terrestrial system under periglacial influence, where material influx was related to erosion process from the melt water discharge, because of the proximity to the Collins Glacier ice cap. After the major Holocene glacier advance dated at about 3500 yr BP, the ice cap retreat led to the formation of Lake Uruguay, which involved in filling processes leading to moraine deposits, proglacial meltwater channels, and lakes next to the land glacier. During the second stage, with the onset of the Current Warm Period, prior to 1900 CE the stabilization of the Zr/Rb ratio within the laminated sediments documented the origin of the lacustrine sedimentation system, with subsequent increases in the sedimentation rate and biomass content (total nitrogen and organic carbon). Time series analyses revealed that the lake displayed variability cycles related to El Niño Southern Oscillation (ENSO), as reflected by high resolution sedimentological proxies for grain size, weathering, allochthonous inputs from the watershed, increase of biomass and productivity, and changes in redox conditions, all of which displayed similar oscillation cycles from 2 to 6 yr. During this periglacial recession and associated eutrophication process, we detected a striking loss in both bacterial specific richness and diversity as inferred from preliminary selected ancient DNA analyses. Thus, the Antarctic warming scenario leading to glacier depletion appears to exert deterioration consequences on the Subantarctic microbial web.
Restringido
Characterization of plastic beach litter by Raman spectroscopy in South-western Spain
(Elsevier BV, 2020-11-20) Asensio Montesinos, F.; Oliva Ramírez, M.; González Leal, J. M.; Carrizo, D.; Anfuso, G.; Universidad de Cádiz (UCA); Asensio Montesinos, F. [0000-0002-8358-2610]; Anfuso, G. [0000-0002-7266-2842]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
The characteristics and distribution of plastic litter were evaluated in October 2018 at 40 beaches along the coast of Cádiz Province, in Spain. A total of 14,261 plastic items, appertaining to 57 litter groups, were identified along the study area at different beach zones, i.e. at low tide water level (2%), along the foreshore (6%), at high tide water level (67%) and in the backshore area (25%). Plastic items have a great floatability, being this one of the main reasons for their proportional dominance among beach litter, especially in the wrack line. Hundreds of measurements were made of different items using Raman spectroscopy, an effective technique to determine the type of plastic. Cellulose acetate represented the most abundant material (79%) linked to cigarette butts, followed by polypropylene, 9% and polyethylene, 8%. The remaining were composed by polystyrene, polyethylene terephthalate and polyvinyl chloride. Smoke related items were the most common in the study area, followed by film and hard pieces, cotton bud sticks, fishing strings, food wrappers, caps/lids and single-use plastics. Beach litter can be related to beachgoers but some categories can be attributed to fishing activities or wastewater discharges. Plastics cause a multitude of damages to the coastal ecosystem, due to their toxic components and adsorbed substances and their facility of fragmentation and dispersion. Principal objective is the compositional characterization of plastic beach litter items and their spatial variability. It is therefore important to avoid unnecessary consumption, promote recycling and use other materials that are less harmful to the environment.
Acceso Abierto
Constraining the preservation of organic compounds in Mars analog nontronites after exposure to acid and alkaline fluids.
(Nature Research Journals, 2020-09-15) Gil Lozano, C.; Fairén, Alberto G.; Muñoz Iglesias, V.; Fernández Sampedro, M.; Prieto Ballesteros, O.; Gago Duport, L.; Losa Adams, E.; Carrizo, D.; Bishop, J. L.; Fornaro, T.; Mateo Martí, Eva; European Research Council (ERC); Agencia Estatal de Investigación (AEI); European Commission (EC); 0000-0002-5536-2565; 0000-0003-1932-7591; 0000-0002-1159-9093; 0000-0003-3500-2850; 0000-0002-2278-1210; 0000-0002-2646-5995; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
The presence of organic matter in lacustrine mudstone sediments at Gale crater was revealed by the Mars Science Laboratory Curiosity rover, which also identified smectite clay minerals. Analogue experiments on phyllosilicates formed under low temperature aqueous conditons have illustrated that these are excellent reservoirs to host organic compounds against the harsh surface conditions of Mars. Here, we evaluate whether the capacity of smectites to preserve organic compounds can be influenced by a short exposure to different diagenetic fluids. We analyzed the stability of glycine embedded within nontronite samples previously exposed to either acidic or alkaline fluids (hereafter referred to as "treated nontronites") under Mars-like surface conditions. Analyses performed using multiple techniques showed higher photodegradation of glycine in the acid-treated nontronite, triggered by decarboxylation and deamination processes. In constrast, our experiments showed that glycine molecules were preferably incorporated by ion exchange in the interlayer region of the alkali-treated nontronite, conferring them a better protection against the external conditions. Our results demonstrate that smectite previously exposed to fluids with different pH values influences how glycine is adsorbed into their interlayer regions, affecting their potential for preservation of organic compounds under contemporary Mars surface conditions.
Acceso Abierto
Dark microbiome and extremely low organics in Atacama fossil delta unveil Mars life detection limits
(Nature Publishing Group, 2023-02-21) Azua Bustos, A.; Fairén, A.; González Silva, C.; Prieto Ballesteros, O.; Carrizo, D.; Sánchez García, L.; Parro García, V.; Fernández Martínez, M. A.; Escudero, C.; Muñoz Iglesias, V.; Fernández Sampedro, M.; Molina, A.; García Villadangos, M.; Moreno Paz, M.; Wierzchos, J.; Ascaso, C.; Fornado, Teresa; Brucato, J. R.; Poggiali, G.; Manrique, J. A.; Veneranda, M.; López Reyes, G.; Sanz Arranz, A.; Rull, F.; Ollila, A. M.; Wiens, R. C.; Reyes Newell, Adriana; Clegg, S. M.; Millan, Maëva; Stewart Johnson, Sarah; McIntosh, Ophélie; Szopa, Cyril; Freissinet, Caroline; Sekine, Yasuhito; Fukushi, Keisuke; Morida, Koki; Inoue, Kosuke; Sakuma, Hiroshi; Rampe, E.; European Commission (EC); Ministerio de Economía y Competitividad (MINECO); Japan Society for the Promotion of Science (JSPS); Comunidad de Madrid; National Aeronautics and Space Administration (NASA); Agenzia Spaziale Italiana (ASI); Agencia Estatal de Investigación (AEI); Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Identifying unequivocal signs of life on Mars is one of the most important objectives for sending missions to the red planet. Here we report Red Stone, a 163-100 My alluvial fan–fan delta that formed under arid conditions in the Atacama Desert, rich in hematite and mudstones containing clays such as vermiculite and smectites, and therefore geologically analogous to Mars. We show that Red Stone samples display an important number of microorganisms with an unusual high rate of phylogenetic indeterminacy, what we refer to as “dark microbiome”, and a mix of biosignatures from extant and ancient microorganisms that can be barely detected with state-of-the-art laboratory equipment. Our analyses by testbed instruments that are on or will be sent to Mars unveil that although the mineralogy of Red Stone matches that detected by ground-based instruments on the red planet, similarly low levels of organics will be hard, if not impossible to detect in Martian rocks depending on the instrument and technique used. Our results stress the importance in returning samples to Earth for conclusively addressing whether life ever existed on Mars.
Restringido
Detection of Potential Lipid Biomarkers in Oxidative Environments by Raman Spectroscopy and Implications for the ExoMars 2020-Raman Laser Spectrometer Instrument Performance.
(Mary Ann Liebert Publishers, 2020-03-02) Carrizo, D.; Muñoz Iglesias, V.; Fernández Sampedro, M.; Gil Lozano, C.; Sánchez García, L.; Prieto Ballesteros, O.; Medina, J.; Rull, F.; Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO); Fernández Sampedro, M. [0000-0003-1932-7591]; Lozano, C. G. [0000-0003-3500-2850]; Muñoz Iglesias, V. [0000-0002-1159-9093]; Sánchez García, L. [0000-0002-7444-1242]; Prieto Ballesteros, O. [0000-0002-2278-1210]; Carrizo, D. [0000-0003-1568-4591]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
The aim of the European Space Agency's ExoMars rover mission is to search for potential traces of present or past life in the swallow subsurface (2 m depth) of Mars. The ExoMars rover mission relies on a suite of analytical instruments envisioned to identify organic compounds with biological value (biomarkers) associated with a mineralogical matrix in a highly oxidative environment. We investigated the feasibility of detecting basic organics (linear and branched lipid molecules) with Raman laser spectroscopy, an instrument onboard the ExoMars rover, when exposed to oxidant conditions. We compared the detectability of six lipid molecules (alkanes, alkanols, fatty acid, and isoprenoid) before and after an oxidation treatment (15 days with hydrogen peroxide), with and without mineral matrix support (amorphous silica rich vs. iron rich). Raman and infrared spectrometry was combined with gas chromatography-mass spectrometry to determine detection limits and technical constrains. We observed different spectral responses to degradation depending on the lipid molecule and mineral substrate, with the silica-rich material showing better preservation of organic signals. These findings will contribute to the interpretation of Raman laser spectroscopy results on cores from the ExoMars rover landing site, the hydrated silica-enriched delta fan on Cogoon Vallis (Oxia Planum).
Acceso Abierto
Fingerprinting molecular and isotopic biosignatures on different hydrothermal scenarios of Iceland, an acidic and sulfur-rich Mars analog
(Springer Nature, 2020-12) Sánchez García, L.; Carrizo, D.; Molina, A.; Muñoz Iglesias, V.; Lezcano, M. A.; Fernández Sampedro, M.; Parro García, V.; Prieto Ballesteros, O.; European Research Council (ERC); Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Detecting signs of potential extant/extinct life on Mars is challenging because the presence of organics on that planet is expected to be very low and most likely linked to radiation-protected refugia and/or preservative strategies (e.g., organo-mineral complexes). With scarcity of organics, accounting for biomineralization and potential relationships between biomarkers, mineralogy, and geochemistry is key in the search for extraterrestrial life. Here we explored microbial fingerprints and their associated mineralogy in Icelandic hydrothermal systems analog to Mars (i.e., high sulfur content, or amorphous silica), to identify potentially habitable locations on that planet. The mineralogical assemblage of four hydrothermal substrates (hot springs biofilms, mud pots, and steaming and inactive fumaroles) was analyzed concerning the distribution of biomarkers. Molecular and isotopic composition of lipids revealed quantitative and compositional differences apparently impacted by surface geothermal alteration and environmental factors. pH and water showed an influence (i.e., greatest biomass in circumneutral settings with highest supply and turnover of water), whereas temperature conditioned the mineralogy that supported specific microbial metabolisms related with sulfur. Raman spectra suggested the possible coexistence of abiotic and biomediated sources of minerals (i.e., sulfur or hematite). These findings may help to interpret future Raman or GC–MS signals in forthcoming Martian missions.
Acceso Abierto
Geomicrobiological Heterogeneity of Lithic Habitats in the Extreme Environment of Antarctic Nunataks: A Potential Early Mars Analog
(Extreme Microbiology, 2021-07-02) Fernández Martínez, M. A.; García Villadangos, M.; Moreno Paz, M.; Gangloff, V.; Carrizo, D.; Blanco, Y.; González, Y.; González, S.; Sánchez García, L.; Prieto Ballesteros, O.; Altshuler, I.; Whyte, Lyle; Parro García, V.; Fairén, Alberto G.; Agencia Estatal de Investigación (AEI); European Research Council (ERC); Comunidad de Madrid; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Nunataks are permanent ice-free rocky peaks that project above ice caps in polar regions, thus being exposed to extreme climatic conditions throughout the year. They undergo extremely low temperatures and scarcity of liquid water in winter, while receiving high incident and reflected (albedo) UVA-B radiation in summer. Here, we investigate the geomicrobiology of the permanently exposed lithic substrates of nunataks from Livingston Island (South Shetlands, Antarctic Peninsula), with focus on prokaryotic community structure and their main metabolic traits. Contrarily to first hypothesis, an extensive sampling based on different gradients and multianalytical approaches demonstrated significant differences for most geomicrobiological parameters between the bedrock, soil, and loose rock substrates, which overlapped any other regional variation. Brevibacillus genus dominated on bedrock and soil substrates, while loose rocks contained a diverse microbial community, including Actinobacteria, Alphaproteobacteria and abundant Cyanobacteria inhabiting the milder and diverse microhabitats within. Archaea, a domain never described before in similar Antarctic environments, were also consistently found in the three substrates, but being more abundant and potentially more active in soils. Stable isotopic ratios of total carbon (δ 13C) and nitrogen (δ 15N), soluble anions concentrations, and the detection of proteins involved in key metabolisms via the Life Detector Chip (LDChip), suggest that microbial primary production has a pivotal role in nutrient cycling at these exposed areas with limited deposition of nutrients. Detection of stress-resistance proteins, such as molecular chaperons, suggests microbial molecular adaptation mechanisms to cope with these harsh conditions. Since early Mars may have encompassed analogous environmental conditions as the ones found in these Antarctic nunataks, our study also contributes to the understanding of the metabolic features and biomarker profiles of a potential Martian microbiota, as well as the use of LDChip in future life detection missions.
Restringido
Identification of microplastics in wastewater samples by means of polarized light optical microscopy.
(Springer Link, 2020-03-01) Sierra, I.; Rodríguez Chialanza, M.; Faccio, R.; Carrizo, D.; Fornaro, L.; Pérez Parada, A.; Agencia Nacional de Investigación e Innovación, Portugal (ANII); Faccio, R. [0000-0003-1650-7677]; Pérez Parada, A. [0000-0003-0321-8171]; Carrizo, D. [0000-0003-1568-4591]; Rodríguez Chialanza, M. [0000-0002-9890-0933]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Many reports state the potential hazards of microplastics (MPs) and their implications to wildlife and human health. The presence of MP in the aquatic environment is related to several origins but particularly associated to their occurrence in wastewater effluents. The determination of MP in these complex samples is a challenge. Current analytical procedures for MP monitoring are based on separation and counting by visual observation or mediated with some type of microscopy with further identification by techniques such as Raman or Fourier-transform infrared (FTIR) spectroscopy. In this work, a simple alternative for the separation, counting and identification of MP in wastewater samples is reported. The presented sample preparation technique with further polarized light optical microscopy (PLOM) observation positively identified the vast majority of MP particles occurring in wastewater samples of Montevideo, Uruguay, in the 70–600 μm range. MPs with different shapes and chemical composition were identified by PLOM and confirmed by confocal Raman microscopy. Rapid identification of polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET) were evidenced. A major limitation was found in the identification of MP from non-birefringent polymers such as PVC (polyvinylchloride). The proposed procedure for MP analysis in wastewater is easy to be implemented at any analytical laboratory. A pilot monitoring of Montevideo WWTP effluents was carried out over 3-month period identifying MP from different chemical identities in the range 5.3–8.2 × 103 MP items/m3.
Acceso Abierto
Inhabited subsurface wet smectites in the hyperarid core of the Atacama Desert as an analog for the search for life on Mars
(Nature Research Journals, 2020-11-05) Azua Bustos, A.; Fairén, Alberto G.; González Silva, C.; Carrizo, D.; Fernández Martínez, M. A.; Arenas Fajardo, C.; Fernández Sampedro, M.; Gil Lozano, C.; Sánchez García, L.; Ascaso, C.; Wierzchos, J.; Rampe, E. B.; European Research Council (ERC); Agencia Estatal de Investigación (AEI); Sánchez García, L. [0000-0002-7444-1242]; Lozano, C. G. [0000-0003-3500-2850]; Fernández Sampedro, M. [0000-0003-1932-7591]
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.
Restringido
Mesoplastics and large microplastics along a use gradient on the Uruguay Atlantic coast: Types, sources, fates, and chemical loads
(Elsevier BV, 2020-06-15) Rodríguez, C.; Fossatti, M.; Carrizo, D.; Sánchez García, L.; Teixeira de Mello, F.; Weinstein, F.; Lozoya, J. P.; Sánchez García, L. [0000-0002-7444-1242]; Lozoya, J. P. [0000-0001-5087-1005]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Plastic pollution is a global problem with great local and regional variability. Plastic litter reaches beaches directly and indirectly through different pathways, due to both terrestrial and marine pressures. In this study, we assess and characterize meso and microplastic pollution on four Uruguayan oceanic beaches along a gradient of tourist use within a complex regional coastal marine system. In Punta del Diablo we found a total mean density of 106 items m−2 of different debris (pellets, fragments, and foams) with different polymeric compositions, and diverse persistent bioaccumulative and toxic chemicals (PAHs, PCBs, OCs, heavy metals). However, the trend of plastic debris densities along this gradient was not what was expected. Fabeiro, one of the sites furthest from the urban center, had the highest total mean density of plastics (292 items m−2) suggesting that marine influences (winds, currents, and beach orientation) have a preponderant role in the distribution of micro and mesoplastics. Meanwhile, the density in the urban site (Pueblo) was highest during summer (March, 201 items m−2), 200 times higher than the density observed in winter (July, 1 item m−2). Although this difference could be associated to the peak season (southern summer), the analysis of types of plastics (171 pellets m−2 vs. 8 cigarette butts m−2) suggested a predominance of marine inputs. Seasonal changes in the configuration of the beaches due to natural geomorphological dynamics imply alternating states (Source or Sink of debris) that also affect the final density of plastics in the system. The relative importance of both sources is highly variable throughout the year and understanding them may directly improve beach management and stranded coastal plastic litter cleaning.
Restringido
Molecular and isotopic biogeochemistry on recently-formed soils on King George Island (Maritime Antarctica) after glacier retreat upon warming climate
(Elsevier BV, 2021-02-10) Vega García, S.; Sánchez García, L.; Prieto Ballesteros, O.; Carrizo, D.; Instituto Antartico Uruguayo (IAU); Agencia Estatal de Investigación (AEI); Comunidad de Madrid; Sánchez García, L. [0000-0002-7444-1242]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Maritime Antarctica is a climate-sensitive region that has experienced a continuous increase of temperature over the last 50 years. This phenomenon accelerates glacier retreat and promotes the exposure of ice-covered surfaces, triggering physico-chemical alteration of the ground and subsequent soil formation. Here, we studied the biogeochemical composition and evolution extent of soil on three recently exposed peninsulas (Fildes, Barton and Potter) on Southwest (SW) King George Island (KGI). Nine soil samples were analyzed for their lipid biomarkers, stable isotope composition, bulk geochemistry and mineralogy. Their biomarkers profiles were compared to those of local fresh biomass of microbial mats (n = 3) and vegetation (1 moss, 1 grass, and 3 lichens) to assess their contribution to the soil organic matter (SOM). The molecular and isotopic distribution of lipids in the soil samples revealed contributions to the SOM dominated by biogenic sources, mostly vegetal (i.e. odd HMW n-alkanes distributions and generally depleted δ13C ratios). Microbial sources were also present to a lesser extent (i.e. even LMW n-alkanes and n-alkanoic acids, heptadecane, 1-alkenes, 9-octadecenoic acid, or iso/anteiso 15: 0 and 17:0 alkanoic acids). Additional contribution from petrogenic sources (bedrock erosion-derived hydrocarbons) was also considered although found to be minor. Results from mineralogy (relative abundance of plagioclases and virtual absence of clay minerals) and bulk geochemistry (low chemical weathering indexes) suggested little chemical alteration of the original geology. This together with the low content of total nitrogen and organic carbon, as well as moderate microbial activity in the soils, confirmed little edaphological development on the recently-exposed KGI surfaces. This study provides molecular and isotopic fingerprints of SOM composition in young Antarctic soils, and contributes to the understanding of soil formation and biogeochemistry in this unexplored region which is currently being affected by thermal destabilization.
Acceso Abierto
Simulating Mars Drilling Mission for Searching for Life: Ground-Truthing Lipids and Other Complex Microbial Biomarkers in the Iron-Sulfur Rich Río Tinto Analog.
(Mary Ann Liebert Publishers, 2020-09-15) Sánchez García, L.; Fernández Martínez, M. A.; Moreno Paz, M.; Carrizo, D.; García Villadangos, M.; Manchado, J. M.; Stoker, C. R.; Glass, B.; Parro García, V.; Ministerio de Economía y Competitividad (MINECO); National Aeronautics and Space Administration (NASA); Sánchez García, L. [0000-0002-7444-1242]; Carrizo, D. [0000-0003-1568-4591]; Fernández Martínez, M. A. [0000-0003-1694-7832]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Sulfate and iron oxide deposits in Río Tinto (Southwestern Spain) are a terrestrial analog of early martian hematite-rich regions. Understanding the distribution and drivers of microbial life in iron-rich environments can give critical clues on how to search for biosignatures on Mars. We simulated a robotic drilling mission searching for signs of life in the martian subsurface, by using a 1m-class planetary prototype drill mounted on a full-scale mockup of NASA's Phoenix and InSight lander platforms. We demonstrated fully automated and aseptic drilling on iron and sulfur rich sediments at the Río Tinto riverbanks, and sample transfer and delivery to sterile containers and analytical instruments. As a ground-truth study, samples were analyzed in the field with the life detector chip immunoassay for searching microbial markers, and then in the laboratory with X-ray diffraction to determine mineralogy, gas chromatography/mass spectrometry for lipid composition, isotope-ratio mass spectrometry for isotopic ratios, and 16S/18S rRNA genes sequencing for biodiversity. A ubiquitous presence of microbial biomarkers distributed along the 1m-depth subsurface was influenced by the local mineralogy and geochemistry. The spatial heterogeneity of abiotic variables at local scale highlights the importance of considering drill replicates in future martian drilling missions. The multi-analytical approach provided proof of concept that molecular biomarkers varying in compositional nature, preservation potential, and taxonomic specificity can be recovered from shallow drilling on iron-rich Mars analogues by using an automated life-detection lander prototype, such as the one proposed for NASA's IceBreaker mission proposal.
Acceso Abierto
Time-Integrative Multibiomarker Detection in Triassic–Jurassic Rocks from the Atacama Desert: Relevance to the Search for Basic Life Beyond Earth
(Mary Ann Liebert Publishers, 2021-10-28) Sánchez García, L.; Carrizo, D.; Lezcano, M. A.; Moreno Paz, M.; Aeppli, C.; García Villadangos, M.; Prieto Ballesteros, O.; Demergasso, C.; Chong, G.; Parro García, V.; Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO); Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Detecting evidence of life on other planetary bodies requires a certain understanding of known biomarkers and their chemical nature, preservation potential, or biological specificity. In a planetary search for life, carbonates are of special interest due to their known association with life as we know it. On Earth, carbonates serve as an invaluable paleogeochemical archive of fossils of up to billions of years old. Here, we investigated biomarker profiles on three Chilean Triassic–Jurassic sedimentary records regarding our search for signs of past and present life over ∼200 Ma. A multianalytical platform that combines lipid-derived biomarkers, metaproteomics, and a life detector chip (LDChip) is considered in the detection of biomolecules with different perdurability and source-diagnosis potential. The combined identification of proteins with positive LDChip inmunodetections provides metabolic information and taxonomic affiliation of modern/subrecent biosignatures. Molecular and isotopic analysis of more perdurable hydrocarbon cores allows for the identification of general biosources and dominant autotrophic pathways over time, as well as recreation of prevailing redox conditions over ∼200 Ma. We demonstrate how extraterrestrial life detection can benefit from the use of different biomarkers to overcome diagnosis limitations due to a lack of specificity and/or alteration over time. Our findings have implications for future astrobiological missions to Mars.