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Background levels of methane in Mars’ atmosphere show strong seasonal variations
(Science, 2018-06-08) Webster, Christopher R.; Mahaffy, Paul R.; Atreya, Sushil K.; Moores, John E.; Flesch, Gregory J.; Malespin, Charles A.; McKay, Christopher P.; Martínez, Germán M.; Smith, Christina L.; Martín Torres, Javier; Gómez Elvira, J.; Paz Zorzano, M.; Wong, Michael H.; Trainer, Melissa G.; Steele, Andrew; Archer, Doug; Sutter, Brad; Coll, Patrice J.; Freissinet, Caroline; Meslin, Pierre-Yves; Gough, Raina V.; House, Christopher H.; Pavlov, Alexander; Eigenbrode, Jennifer L.; Glavin, Daniel P.; Pearson, John C.; Keymeulen, Didier; Christensen, Lance E.; Schwenzer, Susanne P.; Navarro González, R.; Pla García, J.; Rafkin, Scot C. R.; Vicente Retortillo, Álvaro; Kahanpää, H.; Viúdez Moreiras, Daniel; Smith, Michael D.; Harri, Ari-Matti; Genzer, María; Hassler, Donald M.; Lemmon, M. T.; Crisp, Joy; Sander, Stanley P.; Zurek, Richard W.; Vasavada, Ashwin R.; National Aeronautics and Space Administration (NASA)
Variable levels of methane in the martian atmosphere have eluded explanation partly because the measurements are not repeatable in time or location. We report in situ measurements at Gale crater made over a 5-year period by the Tunable Laser Spectrometer on the Curiosity rover. The background levels of methane have a mean value 0.41 ± 0.16 parts per billion by volume (ppbv) (95% confidence interval) and exhibit a strong, repeatable seasonal variation (0.24 to 0.65 ppbv). This variation is greater than that predicted from either ultraviolet degradation of impact-delivered organics on the surface or from the annual surface pressure cycle. The large seasonal variation in the background and occurrences of higher temporary spikes (~7 ppbv) are consistent with small localized sources of methane released from martian surface or subsurface reservoirs.
Acceso Abierto
Freeze Substitution Accelerated via Agitation: New Prospects for Ultrastructural Studies of Lichen Symbionts and Their Extracellular Matrix
(Multidisciplinary Digital Publishing Institute, 2023-11-30) Reipert, Siegfried; Gruber, Daniela; Cyran, Norbert; Schmidt, Brigitte; De la Torre Noetzel, R.; García Sancho, Leopoldo; Goga, Michal; Bačkor, Martin; Schmidt, Katy; de la Torre Noetzel, Maria Rosa; Slovak Research and Development Agency; Slovak Grant Agency KEGA; Ministerio de Ciencia e Innovación (MICINN); Agencia Estatal de Investigación (AEI)
settingsOrder Article Reprints Open AccessArticle Freeze Substitution Accelerated via Agitation: New Prospects for Ultrastructural Studies of Lichen Symbionts and Their Extracellular Matrix by Siegfried Reipert 1,*ORCID,Daniela Gruber 1,Norbert Cyran 1,Brigitte Schmidt 1,Rosa de la Torre Noetzel 2,Leopoldo G. Sancho 3ORCID,Michal Goga 4,Martin Bačkor 4,5ORCID andKaty Schmidt 1 1 Cell Imaging and Ultrastructural Research, University of Vienna, A-1030 Vienna, Austria 2 Department of Earth Observation, National Institute for Aerospace Technology, 28850 Madrid, Spain 3 Section of Botany, Faculty of Pharmacy, University Complutense Madrid, 28040 Madrid, Spain 4 Institute of Biology and Ecology, Pavol Jozef Šafárik University, 040 01 Košice, Slovakia 5 Institute of Biotechnology, Faculty of Biotechnology and Food Sciences, Slovak University of Agriculture, 949 76 Nitra, Slovakia * Author to whom correspondence should be addressed. Plants 2023, 12(23), 4039; https://doi.org/10.3390/plants12234039 Submission received: 21 October 2023 / Revised: 22 November 2023 / Accepted: 27 November 2023 / Published: 30 November 2023 (This article belongs to the Special Issue Microscopy Techniques in Plant Studies) Downloadkeyboard_arrow_down Browse Figures Versions Notes Abstract (1) Background: Lichens, as an important part of the terrestrial ecosystem, attract the attention of various research disciplines. To elucidate their ultrastructure, transmission electron microscopy of resin-embedded samples is indispensable. Since most observations of lichen samples are generated via chemical fixation and processing at room temperature, they lack the rapid immobilization of live processes and are prone to preparation artefacts. To improve their preservation, cryoprocessing was tested in the past, but never widely implemented, not least because of an extremely lengthy protocol. (2) Methods: Here, we introduce an accelerated automated freeze substitution protocol with continuous agitation. Using the example of three lichen species, we demonstrate the preservation of the native state of algal photobionts and mycobionts in association with their extracellular matrix. (3) Results: We bring to attention the extent and the structural variability of the hyphae, the extracellular matrix and numerous crystallized metabolites. Our findings will encourage studies on transformation processes related to the compartmentation of lichen thalli. They include cryopreserved aspects of algal photobionts and observations of putative physiological relevance, such as the arrangement of numerous mitochondria within chloroplast pockets. (4) Conclusions: In summary, we present accelerated freeze substitution as a very useful tool for systematic studies of lichen ultrastructures.
Acceso Abierto
Biosignature stability in space enables their use for life detection on Mars
(Science Advances, 2022-09-07) Baqué, Mickael; Backhaus, Theresa; Meeßen, Joachim; Hanke, Franziska; Böttger, Ute; Ramkissoon, Nisha; Olsson-Francis, Karen; Baumgärtner, Michael; Billi, Daniela; Cassaro, Alessia; De la Torre Noetzel, R.; Demets, René; Edwards, Howell; Ehrenfreund, P.; Elsaesser, Andreas; Foing, Bernard; Foucher, Frédéric; Huwe, Björn; Joshi, Jasmin; Kozyrovska, Natalia; Lasch, Peter; Lee, Natuschka; Leuko, Stefan; Onofri, Silvano; Ott, Sieglinde; Pacelli, Claudia; Rabbow, Elke; Rothschild, Lynn; Schulze Makuch, D.; Selbmann, Laura; Serrano, Paloma; Szewzyk, Ulrich; Verseux, Cyprien; Wagner, Dirk; Westall, Frances; Zucconi, Laura; De Vera, Jean Pierre; de la Torre Noetzel, Maria Rosa; Agenzia Spaziale Italiana (ASI); Bundesministerium für Wirtschaft und Energie (BMWi); Deutsches Zentrum für Luft- und Raumfahrt (DLR); Volkswagen Foundation; "Deutsche Forschungsgemeinschaft (DFG)
Two rover missions to Mars aim to detect biomolecules as a sign of extinct or extant life with, among other instruments, Raman spectrometers. However, there are many unknowns about the stability of Raman-detectable biomolecules in the martian environment, clouding the interpretation of the results. To quantify Raman-detectable biomolecule stability, we exposed seven biomolecules for 469 days to a simulated martian environment outside the International Space Station. Ultraviolet radiation (UVR) strongly changed the Raman spectra signals, but only minor change was observed when samples were shielded from UVR. These findings provide support for Mars mission operations searching for biosignatures in the subsurface. This experiment demonstrates the detectability of biomolecules by Raman spectroscopy in Mars regolith analogs after space exposure and lays the groundwork for a consolidated space-proven database of spectroscopy biosignatures in targeted environments.
Restringido
Detection of new biohints on lichens with Raman spectroscopy after space- and Mars like conditions exposure: Mission Ground Reference (MGR) samples
(Elsevier, 2021-11-15) López-Ramírez, Maria Rosa; Sancho García, Leopoldo; De Vera, Jean Pierre; Baqué, Mickael; Böttger, Ute; Rabbow, Elke; Martínez Frías, Jesús; De la Torre Noetzel, R.; de la Torre Noetzel, Maria Rosa; Ministerio de Economía y Competitividad (MINECO)
The extremophile lichen Circinaria gyrosa (C. gyrosa) is one of the selected species within the BIOMEX (Biology and Mars Experiment) experiment. Here we present the Raman study of a biohint found in this lichen, called whewellite (calcium oxalate monohydrate), and other organic compounds and mineral products of the biological activity of the astrobiologically relevant model system C. gyrosa. Samples were exposed to space- and simulated Mars-like conditions during the EXPOSE-R2 mission parallel ground reference experiment MGR performed at the space- and planetary chambers of DLR-Cologne to study Mars’ habitability and resistance to real space conditions. In this work, we complete the information of natural C. gyrosa about the process of diagenesis by the identification of carbonate crystals in the inner medulla together with the biomineral whewellite. The analysis by Raman spectroscopy of simulated Space and Mars exposed samples confirm alterations and damages of the photobiont part of the lichen and changes related to the molecular structure of whewellite. The conclusions of this work will be important to understand what are the effects to consider when biological systems are exposed to space or Mars-like conditions and to expand our knowledge of how life survives in most extreme conditions that is a prerequisite in future planetary exploration projects.
Restringido
Lichen Vitality After a Space Flight on Board the EXPOSE-R2 Facility Outside the International Space Station: Results of the Biology and Mars Experiment
(Mary Ann Liebert, 2020-04-30) De la Torre Noetzel, R.; Ortega García, M. V.; Miller, Ana Zélia; Bassy, O.; Granja, Carmen; Cubero, Beatriz; Jordão, Luisa; Martínez Frías, Jesús; Rabbow, Elke; Backhaus, Theresa; Ott, Sieglinde; García Sancho, Leopoldo; Paul de Vera, Jean-Pierre; de la Torre Noetzel, Maria Rosa; Ortega García, María Victoria
As part of the Biology and Mars Experiment (BIOMEX; ILSRA 2009-0834), samples of the lichen Circinaria gyrosa were placed on the exposure platform EXPOSE-R2, on the International Space Station (ISS) and exposed to space and to a Mars-simulated environment for 18 months (2014–2016) to study: (1) resistance to space and Mars-like conditions and (2) biomarkers for use in future space missions (Exo-Mars). When the experiment returned (June 2016), initial analysis showed rapid recovery of photosystem II activity in the samples exposed exclusively to space vacuum and a Mars-like atmosphere. Significantly reduced recovery levels were observed in Sun-exposed samples, and electron and fluorescence microscopy (transmission electron microscope and field emission scanning electron microscope) data indicated that this was attributable to the combined effects of space radiation and space vacuum, as unirradiated samples exhibited less marked morphological changes compared with Sun-exposed samples. Polymerase chain reaction analyses confirmed that there was DNA damage in lichen exposed to harsh space and Mars-like environmental conditions, with ultraviolet radiation combined with space vacuum causing the most damage. These findings contribute to the characterization of space- and Mars-resistant organisms that are relevant to Mars habitability.
Acceso Abierto
Limits of Life and the Habitability of Mars: The ESA Space Experiment BIOMEX on the ISS
(Mary Ann Liebert, 2019-02-11) De Vera, Jean Pierre; Alawi, Mashal; Backhaus, Theresa; Baqué, Mickael; Billi, Daniela; Böttger, Ute; Berger, T.; Bohmeier, M.; Cockell, Charles S.; Demets, René; De la Torre Noetzel, R.; Edwards, Howell; Elsaesser, Andreas; Fagliarone, Claudia; Fiedler, Annelie; Foing, Bernard; Foucher, Frédéric; Fritz, Jörg; Hanke, Franziska; Herzog, Thomas; Horneck, Gerda; Hübers, Heinz-Wilhelm; Huwe, Björn; Joshi, Jasmin; Kozyrovska, Natalia; Kruchten, Martha; Lasch, Peter; Lee, Natuschka; Leuko, Stefan; Leya, Thomas; Lorek, Andreas; Martínez Frías, Jesús; Meessen, Joachim; Moritz, Sophie; Moeller, Ralf; Olsson-Francis, Karen; Onofri, Silvano; Ott, Sieglinde; Pacelli, Claudia; Podolich, Olga; Rabbow, Elke; Reitz, Günther; Rettberg, Petra; Reva, Oleg; Rothschild, Lynn; García Sancho, Leo; Schulze Makuch, D.; Selbmann, Laura; Serrano, Paloma; Szewzyk, Ulrich; Verseux, Cyprien; Wadsworth, Jennifer; Wagner, Dirk; Westall, Frances; Wolter, David; Zucconi, Laura; de la Torre Noetzel, Maria Rosa; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); Agenzia Spaziale Italiana (ASI); National Academy of Sciences of Ukraine (NASU); German Centre for Air and Space Travel; Helmholtz Association
BIOMEX (BIOlogy and Mars EXperiment) is an ESA/Roscosmos space exposure experiment housed within the exposure facility EXPOSE-R2 outside the Zvezda module on the International Space Station (ISS). The design of the multiuser facility supports—among others—the BIOMEX investigations into the stability and level of degradation of space-exposed biosignatures such as pigments, secondary metabolites, and cell surfaces in contact with a terrestrial and Mars analog mineral environment. In parallel, analysis on the viability of the investigated organisms has provided relevant data for evaluation of the habitability of Mars, for the limits of life, and for the likelihood of an interplanetary transfer of life (theory of lithopanspermia). In this project, lichens, archaea, bacteria, cyanobacteria, snow/permafrost algae, meristematic black fungi, and bryophytes from alpine and polar habitats were embedded, grown, and cultured on a mixture of martian and lunar regolith analogs or other terrestrial minerals. The organisms and regolith analogs and terrestrial mineral mixtures were then exposed to space and to simulated Mars-like conditions by way of the EXPOSE-R2 facility. In this special issue, we present the first set of data obtained in reference to our investigation into the habitability of Mars and limits of life. This project was initiated and implemented by the BIOMEX group, an international and interdisciplinary consortium of 30 institutes in 12 countries on 3 continents. Preflight tests for sample selection, results from ground-based simulation experiments, and the space experiments themselves are presented and include a complete overview of the scientific processes required for this space experiment and postflight analysis. The presented BIOMEX concept could be scaled up to future exposure experiments on the Moon and will serve as a pretest in low Earth orbit.
Acceso Abierto
Airborne Bacterial Community Composition According to Their Origin in Tenerife, Canary Islands
(Frontiers Media, 2021-10-14) González Martín, Cristina; Pérez González, Carlos J.; González Toril, Elena; Expósito, Francisco Javier; Aguilera, Ángeles; Díaz, Juan P.; Agencia Estatal de Investigación (AEI); European Commission (EC); Cabildo de Gran Canaria; Ministerio para la Transición Ecológica y el Reto Demográfico (MITECO)
Microorganisms are ubiquitous in the environment, and the atmosphere is no exception. However, airborne bacterial communities are some of the least studied. Increasing our knowledge about these communities and how environmental factors shape them is key to understanding disease outbreaks and transmission routes. We describe airborne bacterial communities at two different sites in Tenerife, La Laguna (urban, 600 m.a.s.l.) and Izaña (high mountain, 2,400 m.a.s.l.), and how they change throughout the year. Illumina MiSeq sequencing was used to target 16S rRNA genes in 293 samples. Results indicated a predominance of Proteobacteria at both sites (>65%), followed by Bacteroidetes, Actinobacteria, and Firmicutes. Gammaproteobacteria were the most frequent within the Proteobacteria phylum during spring and winter, while Alphaproteobacteria dominated in the fall and summer. Within the 519 genera identified, Cellvibrio was the most frequent during spring (35.75%) and winter (30.73%); Limnobacter (24.49%) and Blastomonas (19.88%) dominated in the summer; and Sediminibacterium represented 10.26 and 12.41% of fall and winter samples, respectively. Sphingomonas was also identified in 17.15% of the fall samples. These five genera were more abundant at the high mountain site, while other common airborne bacteria were more frequent at the urban site (Kocuria, Delftia, Mesorhizobium, and Methylobacterium). Diversity values showed different patterns for both sites, with higher values during the cooler seasons in Izaña, whereas the opposite was observed in La Laguna. Regarding wind back trajectories, Tropical air masses were significantly different from African ones at both sites, showing the highest diversity and characterized by genera regularly associated with humans (Pseudomonas, Sphingomonas, and Cloacibacterium), as well as others related to extreme conditions (Alicyclobacillus) or typically associated with animals (Lachnospiraceae). Marine and African air masses were consistent and very similar in their microbial composition. By contrast, European trajectories were dominated by Cellvibrio, Pseudomonas, Pseudoxanthomonas, and Sediminibacterium. These data contribute to our current state of knowledge in the field of atmospheric microbiology. However, future studies are needed to increase our understanding of the influence of different environmental factors on atmospheric microbial dispersion and the potential impact of airborne microorganisms on ecosystems and public health.
Restringido
Metagenomic and metabolic analyses of poly-extreme microbiome from an active crater volcano lake
(Elsevier, 2022-01) Peña Ocaña, Betsy Anaid; Ovando Ovando, César Ivan; Puente Sánchez, Fernando; Tamames, Javier; Servín Garcidueñas, Luis Eduardo; González Toril, Elena; Gutiérrez Sarmiento, Wilbert; Jasso Chávez, Ricardo; Ruíz Valdiviezo, Víctor Manuel
El Chichón volcano is one of the most active volcanoes in Mexico. Previous studies have described its poly-extreme conditions and its bacterial composition, although the functional features of the complete microbiome have not been characterized yet. By using metabarcoding analysis, metagenomics, metabolomics and enzymology techniques, the microbiome of the crater lake was characterized in this study. New information is provided on the taxonomic and functional diversity of the representative Archaea phyla, Crenarchaeota and Euryarchaeota, as well as those that are representative of Bacteria, Thermotogales and Aquificae. With culture of microbial consortia and with the genetic information collected from the natural environment sampling, metabolic interactions were identified between prokaryotes, which can withstand multiple extreme conditions. The existence of a close relationship between the biogeochemical cycles of carbon and sulfur in an active volcano has been proposed, while the relationship in the energy metabolism of thermoacidophilic bacteria and archaea in this multi-extreme environment was biochemically revealed for the first time. These findings contribute towards understanding microbial metabolism under extreme conditions, and provide potential knowledge pertaining to "microbial dark matter", which can be applied to biotechnological processes and evolutionary studies.
Acceso Abierto
Ecological degradation of a fragile semi-arid wetland and the implications in its microbial community: The case study of Las Tablas de Daimiel National Park (Spain)
(Elsevier, 2024-05-10) Santofimia, Esther; González Toril, Elena; De Diego Castilla, Graciela; Rincón-Tomás, Blanca; Aguilera, Á.; Agencia Estatal de Investigación (AEI); European Commission (EC); Ministerio de Agricultura, Alimentación y Medio Ambiente
Las Tablas de Daimiel National Park (TDNP, Iberian Peninsula) is a semi-arid wetland of international significance for waterfowl and serves as a migratory route for various bird species. However, TDNP presents strong anthropization and fluctuating water levels, making it a highly fragile ecosystem. Water physico-chemical parameters and microbial diversity of the three domains (Bacteria-Archaea- Eukarya) were analysed in Zone A and Zone B of the wetland (a total of eight stations) during spring and summer, aiming to determine how seasonal changes influence the water quality, trophic status and ultimately, the microbial community composition. Additionally, Photosynthetically Active Radiation (PAR) was used to determine the trophic status instead of transparency using Secchi disk, setting the threshold to 20–40 μmol/sm2 for benthic vegetation growth. In spring, both zones of the wetland were considered eutrophic, and physico-chemical parameters as well as microbial diversity were similar to other wetlands, with most abundant bacteria affiliated to Actinobacteriota, Cyanobacteria, Bacteroidota, Gammaproteobacteria and Verrumicrobiota. Methane-related taxa like Methanosarcinales and photosynthetic Chlorophyta were respectively the most representative archaeal and eukaryotic groups. In summer, phytoplankton bloom led by an unclassified Cyanobacteria and mainly alga Hydrodictyon was observed in Zone A, resulting in an increase of turbidity, pH, phosphorus, nitrogen, chlorophyll-a and phycocyanin indicating the change to hypertrophic state. Microbial community composition was geographical and seasonal shaped within the wetland as response to changes in trophic status. Archaeal diversity decreases and methane-related species increase due to sediment disturbance driven by fish activity, wind, and substantial water depth reduction. Zone B in summer suffers less seasonal changes, maintaining the eutrophic state and still detecting macrophyte growth in some stations. This study provides a new understanding of the interdomain microbial adaptation following the ecological evolution of the wetland, which is crucial to knowing these systems that are ecological niches with high environmental value.
Restringido
Metagenomic analysis of the microbial community at the Riutort oil shale mine (NE Spain): Potential applications in bioremediation and enhanced oil recovery
(Elsevier, 2023-10-10) González Toril, Elena; Permanyer, Albert; Gallego, José R.; Márquez, Gonzalo; Lorenzo, Erica; Aguilera, Á.; Ministerio de Ciencia e Innovación (MICINN); Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI)
Preservation of the environment of the Riutort oil shale mine for more than a century has favored the presence of a paradigmatic ecosystem of oil-degrading microorganisms. After extensive sampling and analysis by 16S rRNA sequencing, a marked prokaryotic community comprising diverse groups of bacteria (genus such as Methylobacter, Thiothrix, and Desulfobacca) and archaea (e.g., Methanobrevibacter genus) with hydrocarbon-degrading activity was found. Aerobic microorganisms were predominant in several samples but facultative microorganisms were also present, and there was an interesting transition to strict anaerobic conditions in some areas. One of the samples contained oil degrading aerobic bacteria such as Pseudomonas spp. and Brevundimonas spp. Of the microbes studied, we conducted a laboratory assessment of the capacity of this specific consortium for bioremediation of petroleum-polluted soil and microbial enhanced oil recovery processes. To this end, we used oily sludge-contaminated soil from La Libertad Refinery and cores from the Ancón Field, respectively, both sites in southwestern Ecuador. The Riutort consortium degraded 50.8% of total petroleum hydrocarbons, 64.2% of saturates, 41.3% of aromatics, and 37.4% of polar compounds after a 60-day incubation using oily sludge as the sole source of carbon. The performance of this consortium reflects its notable potential for bioremediation purposes. In turn, flooding with the natural Riutort consortium and its metabolites achieved a 7.2% (v/v) incremental recovery of crude oil through a sand-pack assay. These results are comparable to those reported using synthetic bacterial consortia, and thus reveal the great interest of the study seepages, not only for understanding microbial activities in oil degradation but also their use in biotechnological applications.
Acceso Abierto
Detecting Nonvolatile Life- and Nonlife-Derived Organics in a Carbonaceous Chondrite Analogue with a New Multiplex Immunoassay and Its Relevance for Planetary Exploration
(Mary Ann Liebert, 2018-08-01) Parro García, V.; Moreno Paz, M.; Gómez Cifuentes, Ana; Ruiz Bermejo, Marta; Hofstetter, Oliver; Maquieira, Ángel; Manchado, J. M.; Morais, Sergi; Sephton, Mark A.; Niessner, Reinhard; Knopp, Dietmar; Instituto Nacional de Técnica Aeroespacial (INTA); Ministerio de Economía y Competitividad (MINECO)
Potential martian molecular targets include those supplied by meteoritic carbonaceous chondrites such as amino acids and polycyclic aromatic hydrocarbons and true biomarkers stemming from any hypothetical martian biota (organic architectures that can be directly related to once-living organisms). Heat extraction and pyrolysis-based methods currently used in planetary exploration are highly aggressive and very often modify the target molecules, making their identification a cumbersome task. We have developed and validated a mild, nondestructive, multiplex inhibitory microarray immunoassay and demonstrated its implementation in the SOLID (Signs of Life Detector) instrument for simultaneous detection of several nonvolatile life- and nonlife-derived organic molecules relevant in planetary exploration and environmental monitoring. By utilizing a set of highly specific antibodies that recognize D- or L-aromatic amino acids (Phe, Tyr, Trp), benzo[a]pyrene (B[a]P), pentachlorophenol, and sulfone-containing aromatic compounds, respectively, the assay was validated in the SOLID instrument for the analysis of carbon-rich samples used as analogues of the organic material in carbonaceous chondrites or even Mars samples. Most of the antibodies enabled sensitivities at the 1–10 ppb level and some even at the part-per-trillion level. The multiplex immunoassay allowed the detection of B[a]P as well as aromatic sulfones in a water/methanol extract of an Early Cretaceous lignite sample (ca. 140 Ma) representing type IV kerogen. No L- or D-aromatic amino acids were detected, reflecting the advanced diagenetic stage and the fossil nature of the sample. The results demonstrate the ability of the liquid extraction by ultrasonication and the versatility of the multiplex inhibitory immunoassays in the SOLID instrument to discriminate between organic matter derived from life and nonlife processes, an essential step toward life detection outside Earth.
Acceso Abierto
In vitro infectivity and differential gene expression of Leishmania infantum metacyclic promastigotes: negative selection with peanut agglutinin in culture versus isolation from the stomodeal valve of Phlebotomus perniciosus
(BMC Genomics, 2016-05-20) Alcolea, Pedro J.; Alonso, Ana; Degayón, María A.; Moreno Paz, M.; Jiménez, Maribel; Molina, Ricardo; Larraga, Vicente; Alcolea Alcolea, Pedro José; Fundación Ramón Areces (FRA); Consejo Superior de Investigaciones Científicas (CSIC); Ministerio de Economía y Competitividad (MINECO)
Background: Leishmania infantum is the protozoan parasite responsible for zoonotic visceral leishmaniasis in the Mediterranean basin. A recent outbreak in humans has been reported in this area. The life cycle of the parasite is digenetic. The promastigote stage develops within the gut of phlebotomine sand flies, whereas amastigotes survive and multiply within phagolysosomes of mammalian host phagocytes. The major vector of L. infantum in Spain is Phlebotomus perniciosus. The axenic culture model of promastigotes is generally used because it is able to mimic the conditions of the natural environment (i.e. the sand fly vector gut). However, infectivity decreases with culture passages and infection of laboratory animals is frequently required. Enrichment of the stationary phase population in highly infective metacyclic promastigotes is achieved by negative selection with peanut agglutinin (PNA), which is possible only in certain Leishmania species such as L. major and L. infantum. In this study, in vitro infectivity and differential gene expression of cultured PNA-negative promastigotes (Pro-PNA−) and metacyclic promastigotes isolated from the sand fly anterior thoracic midgut (Pro-Pper) have been compared. Results: In vitro infectivity is about 30 % higher in terms of rate of infected cells and number of amastigotes per infected cell in Pro-Pper than in Pro-PNA−. This finding is in agreement with up-regulation of a leishmanolysin gene (gp63) and genes involved in biosynthesis of glycosylinositolphospholipids (GIPL), lipophosphoglycan (LPG) and proteophosphoglycan (PPG) in Pro-Pper. In addition, differences between Pro-Pper and Pro-PNA− in genes involved in important cellular processes (e.g. signaling and regulation of gene expression) have been found. Conclusions: Pro-Pper are significantly more infective than peanut lectin non-agglutinating ones. Therefore, negative selection with PNA is an appropriate method for isolating metacyclic promastigotes in stationary phase of axenic culture but it does not allow reaching the in vitro infectivity levels of Pro-Pper. Indeed, GIPL, LPG and PPG biosynthetic genes together with a gp63 gene are up-regulated in Pro-Pper and interestingly, the correlation coefficient between both transcriptomes in terms of transcript abundance is R2 = 0.68. This means that the correlation is sufficiently high to consider that both samples are physiologically comparable (i.e. the experiment was correctly designed and performed) and sufficiently low to conclude that important differences in transcript abundance have been found. Therefore, the implications of axenic culture should be evaluated case-by-case in each experimental design even when the stationary phase population in culture is enriched in metacyclic promastigotes by negative selection with PNA.
Acceso Abierto
Biomarker Profiling of Microbial Mats in the Geothermal Band of Cerro Caliente, Deception Island (Antarctica): Life at the Edge of Heat and Cold
(Mary Ann Liebert, 2019-12-04) Lezcano, M. A.; Moreno Paz, M.; Carrizo, D.; Prieto Ballesteros, O.; Fernández Martínez, Miguel Ángel; Sánchez García, Laura; Blanco, Yolanda; Puente Sánchez, Fernando; De Diego Castilla, Graciela; García Villadangos, M.; Fairén, A.; Parro García, V.; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); European Commission (EC); Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Substrate–atmosphere interfaces in Antarctic geothermal environments are hot–cold regions that constitute thin habitable niches for microorganisms with possible counterparts in ancient Mars. Cerro Caliente hill in Deception Island (active volcano in the South Shetland Islands) is affected by ascending hydrothermal fluids that form a band of warm substrates buffered by low air temperatures. We investigated the influence of temperature on the community structure and metabolism of three microbial mats collected along the geothermal band of Cerro Caliente registering 88°C, 8°C, and 2°C at the time of collection. High-throughput sequencing of small subunit ribosomal ribonucleic acid (SSU rRNA) genes and Life Detector Chip (LDChip) microarray immunoassays revealed different bacterial, archaeal, and eukaryotic composition in the three mats. The mat at 88°C showed the less diverse microbial community and a higher proportion of thermophiles (e.g., Thermales). In contrast, microbial communities in the mats at 2°C and 8°C showed relatively higher diversity and higher proportion of psychrophiles (e.g., Flavobacteriales). Despite this overall association, similar microbial structures at the phylum level (particularly the presence of Cyanobacteria) and certain hot- and cold-tolerant microorganisms were identified in the three mats. Daily thermal oscillations recorded in the substrate over the year (4.5–76°C) may explain the coexistence of microbial fingerprints with different thermal tolerances. Stable isotope composition also revealed metabolic differences among the microbial mats. Carbon isotopic ratios suggested the Calvin–Benson–Bassham cycle as the major pathway for carbon dioxide fixation in the mats at 2°C and 8°C, and the reductive tricarboxylic acid cycle and/or the 3-hydroxypropionate bicycle for the mat at 88°C, indicating different metabolisms as a function of the prevailing temperature of each mat. The comprehensive biomarker profile on the three microbial mats from Cerro Caliente contributes to unravel the diversity, composition, and metabolism in geothermal polar sites and highlights the relevance of geothermal-cold environments to create habitable niches with interest in other planetary environments.
Acceso Abierto
Environmental parameters, and not phylogeny, determine the composition of extracellular polymeric substances in microbial mats from extreme environments
(Elsevier, 2019-02-10) Blanco, Yolanda; Rivas, Luis Alfonso; González Toril, Elena; Ruiz Bermejo, Marta; Moreno Paz, M.; Parro García, V.; Palacín, Arantxa; Aguilera, Á.; Puente Sánchez, Fernando; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI)
The ability to establish biofilms is a key trait for microorganisms growing in extreme environments. The extracellular polymeric substances (EPS) present in biofilms provide not only surface attachment, but also protection against all kinds of environmental stressors, including desiccation, salinity, temperature or heavy metal pollution. The acquisition of suitable biofilm characteristics might thus be an important process mediating the adaptation of microorganisms to novel environmental conditions. In this work we have characterized the EPS of 20 phylogenetically diverse biofilms collected in situ from five contrasting extreme environments, including two geothermal areas (Copahue, Argentina; Seltun, Iceland), two cold areas (Pastoruri glacier, Peru; Byers Peninsula, Antarctica) and one extremely acidic river (Río Tinto, Spain). Biofilms were subjected to biochemical characterization, glycan profiling and immunoprofiling with an antibody microarray. Our results showed that environmental conditions strongly influence biofilm characteristics, with microorganisms from the same environment achieving similar EPS compositions regardless of the phylogeny of their main species. The concentration of some monosaccharides in the EPS could be related to environmental conditions such as temperature or heavy metal toxicity, suggesting that in some cases stress resistance can be mediated by specific sugars. Overall, our results highlight the existence of conserved EPS compositional patterns for each extreme environment, which could in turn be exploited to engineer ecological adaptations in genetically modified microorganisms.
Acceso Abierto
Viable cyanobacteria in the deep continental subsurface
(National Academy of Sciences (U.S.), 2018-10-01) Puente Sánchez, Fernando; Arce Rodríguez, Alejandro; Oggerin, Monike; García Villadangos, M.; Moreno Paz, M.; Blanco, Yolanda; Rodríguez, N.; Bird, Laurence; Lincoln, Sara A.; Tornos, Fernando; Prieto Ballesteros, O.; Freeman, Katherine H.; Pieper, Dietmar H.; Timmis, Kenneth N.; Amils Pibernat, R.; Parro García, V.; Rodríguez Rivas, Noé; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); European Research Council (ERC)
Cyanobacteria are ecologically versatile microorganisms inhabiting most environments, ranging from marine systems to arid deserts. Although they possess several pathways for light-independent energy generation, until now their ecological range appeared to be restricted to environments with at least occasional exposure to sunlight. Here we present molecular, microscopic, and metagenomic evidence that cyanobacteria predominate in deep subsurface rock samples from the Iberian Pyrite Belt Mars analog (southwestern Spain). Metagenomics showed the potential for a hydrogen-based lithoautotrophic cyanobacterial metabolism. Collectively, our results suggest that they may play an important role as primary producers within the deep-Earth biosphere. Our description of this previously unknown ecological niche for cyanobacteria paves the way for models on their origin and evolution, as well as on their potential presence in current or primitive biospheres in other planetary bodies, and on the extant, primitive, and putative extraterrestrial biospheres.
Acceso Abierto
Discriminating sources and preservation of organic matter in surface sediments from five Antarctic lakes in the Fildes Peninsula (King George Island) by lipid biomarkers and compound-specific isotopic analysis
(Elsevier, 2019-04-01) Carrizo, D.; Sánchez García, Laura; Menes, Rodolfo Javier; García Rodríguez, F.; Instituto Antártico Uruguay (IAU)
Lakes are important paleoenvironmental archives retaining abundant information due to their typical high sedimentation rates and susceptibility to environmental changes. Here, we scrutinize the organic matter (OM) composition, origin and preservation state in surface sediments from five lakes in a remote, warming-sensitive, and poorly explored region partially covered by the retreating Collins Glacier in King George Island (Antarctica), the Fildes Peninsula. Lipid biomarkers of terrestrial origin (i.e. high-molecular weight n-alkanes, n-alkanoic acids, and n-alkanols; β-sitosterol, campesterol, and stigmasterol) were detected in the five Fildes Lakes, with the smallest basin (i.e., Meltwater) showing a particularly strong moss imprint. Aquatic source indicators such as low C/N and terrestrial over aquatic ratios (TAR), or less negative δ13C values were preferentially found in the mid-sized lakes (i.e., Drake and Ionospheric). Sedimentary carbon in the larger lakes (i.e., Uruguay and Kitezh) displayed a largely biogenic origin (i.e., values of carbon preference index, CPI, ≫1), whereas the three lakes close to Collins Glacier (i.e., Drake, Meltwater, and Ionospheric) showed certain contribution from petrogenic sources (CPI ~ 1). The results suggest that the geochemical signature of the surface sediments in the five Fildes lakes is determined by factors such as the distance to the retreating Collins Glacier, the proximity to the coast, or the lake depth. This study illustrates the forensic interest of combining lipid biomarkers, compound-specific isotopic analysis, and bulk geochemistry to reconstruct paleoenvironments and study climate-sensitive regions.
Acceso Abierto
Multi-analytical characterization of an oncoid from a high altitude hypersaline lake using techniques employed in the Mars2020 and Rosalind Franklin missions on Mars
(Elsevier, 2023-07-17) Huidobro, J.; Madariaga, J. M.; Carrizo, D.; Laserna, Javier; Rull, F.; Martínez Frías, Jesús; Aramendia, J.; Sánchez García, Laura; García Gómez, Laura; Vignale, Federico A.; Farías, María Eugenia; Veneranda, M.; Población, Iratxe; Cabalín, Luisa María; López Reyes, G.; Coloma, Leire; García Florentino, Carlos; Arana, G.; Castro, K.; Delgado Pérez, Tomás; Alvarez Llamas, César; Fortes, Francisco Javier; Manrique, J. A.; Ministerio de Ciencia e Innovación (MICINN); Agencia Estatal de Investigación (AEI)
In this work, a geological sample of great astrobiological interest was studied through analytical techniques that are currently operating in situ on Mars and others that will operate in the near future. The sample analyzed consisted of an oncoid, which is a type of microbialite, collected in the Salar Carachi Pampa, Argentina. The main peculiarity of microbialites is that they are organo-sedimentary deposits formed by the in situ fixation and precipitation of calcium carbonate due to the growth and metabolic activities of microorganisms. For this reason, the Carachi Pampa oncoid was selected as a Martian analog for astrobiogeochemistry study. In this sense, the sample was characterized by means of the PIXL-like, SuperCam-like and SHERLOC-like instruments, which represent instruments on board the NASA Perseverance rover, and by means of RLS-like and MOMA-like instruments, which represent instruments on board the future ESA Rosalind Franklin rover. It was possible to verify that the most important conclusions and discoveries have been obtained from the combination of the results. Likewise, it was also shown that Perseverance rover-like remote-sensing instruments allowed a first detailed characterization of the biogeochemistry of the Martian surface. With this first characterization, areas of interest for in-depth analysis with Rosalind Franklin-like instruments could be identified. Therefore, from a first remote-sensing elemental identification (PIXL-like instrument), followed by a remote-sensing molecular characterization (SuperCam and SHERLOC-like instruments) and ending with an in-depth microscopic analysis (RLS and MOMA-like instruments), a wide variety of compounds were found. On the one hand, the expected minerals were carbonates, such as aragonite, calcite and high-magnesium calcite. On the other hand, unexpected compounds consisted of minerals related to the Martian/terrestrial surface (feldspars, pyroxenes, hematite) and organic compounds related to the past biological activity related to the oncoid (kerogen, lipid biomarkers and carotenes). Considering samples resembling microbialites have already been found on Mars and that one of the main objectives of the missions is to identify traces of past life, the study of microbialites is a potential way to find biosignatures protected from the inhospitable Martian environment. In addition, it should be noted that in this work, further conclusions have been obtained through the study of the results as a whole, which could also be carried out on Mars.
Acceso Abierto
Broad-band high-resolution rotational spectroscopy for laboratory astrophysics
(EDP Science, 2019-06-07) Cernicharo, J.; Gallego, J. D.; López Pérez, Jose A.; Tercero, Felix; Tanarro, I.; Beltrán, F.; De Vicente, P.; Lauwaet, K.; Alemán, Belén; Moreno, E.; Herrero, V. J.; Doménech, Jose Luis; Ramírez, S. I.; Bermúdez, Celina; Peláez, R. J.; Patino Esteban, Marina; López Fernández, Isaac; García Álvaro, Sonia; García Carreño, Pablo; Cabezas, Carlos; Malo, Inmaculada; Amils Pibernat, R.; Sobrado, J. M.; Díez González, C.; Hernandéz, Jose M.; Tercero, B.; Santoro, G.; Martínez, Lidia; Castellanos, Marcelo; Vaquero Jiménez, B.; Pardo, Juan R.; Barbas, L.; López Fernández, Jose Antonio; Aja, B.; Leuther, A.; Martín Gago, J. A.; Instituto Nacional de Técnica Aeroespacial (INTA); European Commission (EC); Agencia Estatal de Investigación (AEI)
We present a new experimental set-up devoted to the study of gas phase molecules and processes using broad-band high spectral resolution rotational spectroscopy. A reactor chamber is equipped with radio receivers similar to those used by radio astronomers to search for molecular emission in space. The whole range of the Q (31.5–50 GHz) and W bands (72–116.5 GHz) is available for rotational spectroscopy observations. The receivers are equipped with 16 × 2.5 GHz fast Fourier transform spectrometers with a spectral resolution of 38.14 kHz allowing the simultaneous observation of the complete Q band and one-third of the W band. The whole W band can be observed in three settings in which the Q band is always observed. Species such as CH3CN, OCS, and SO2 are detected, together with many of their isotopologues and vibrationally excited states, in very short observing times. The system permits automatic overnight observations, and integration times as long as 2.4 × 105 s have been reached. The chamber is equipped with a radiofrequency source to produce cold plasmas, and with four ultraviolet lamps to study photochemical processes. Plasmas of CH4, N2, CH3CN, NH3, O2, and H2, among other species, have been generated and the molecular products easily identified by the rotational spectrum, and via mass spectrometry and optical spectroscopy. Finally, the rotational spectrum of the lowest energy conformer of CH3CH2NHCHO (N-ethylformamide), a molecule previously characterized in microwave rotational spectroscopy, has been measured up to 116.5 GHz, allowing the accurate determination of its rotational and distortion constants and its search in space.
Acceso Abierto
Mimicking the Martian Hydrological Cycle: A Set-Up to Introduce Liquid Water in Vacuum
(Multidisciplinary Digital Publishing Institute (MDPI), 2020-10-29) Sobrado, J. M.; Instituto Nacional de Técnica Aeroespacial (INTA); Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI)
Liquid water is well known as the life ingredient as a solvent. However, so far, it has only been found in liquid state on this planetary surface. The aim of this experiment and technological development was to test if a moss sample is capable of surviving in Martian conditions. We built a system that simulates the environmental conditions of the red planet including its hydrological cycle. This laboratory facility enables us to control the water cycle in its three phases through temperature, relative humidity, hydration, and pressure with a system that injects water droplets into a vacuum chamber. We successfully simulated the daytime and nighttime of Mars by recreating water condensation and created a layer of superficial ice that protects the sample against external radiation and minimizes the loss of humidity due to evaporation to maintain a moss sample in survival conditions in this extreme environment. We performed the simulations with the design and development of different tools that recreate Martian weather in the MARTE simulation chamber.
Restringido
Prevalence of non-aromatic carbonaceous molecules in the inner regions of circumstellar envelopes
(Nature, 2019-10-21) Martínez, Lidia; Santoro, G.; Merino, P.; Accolla, M.; Lauwaet, K.; Sobrado, J. M.; Sabbah, H.; Peláez, R. J.; Herrero, V. J.; Tanarro, I.; Agúndez, Marcelino; Martín Jiménez, Alberto; Otero, Roberto; Ellis, G. J.; Joblin, C.; Cernicharo, J.; Martín Gago, J. A.; Instituto Nacional de Técnica Aeroespacial (INTA); European Commission (EC); Agencia Estatal de Investigación (AEI)
Evolved stars are foundries of chemical complexity, gas and dust that provide the building blocks of planets and life, and dust nucleation first occurs in their photosphere. The circumstellar regions enveloping these stars, despite their importance, remain hidden to many observations, and dust formation processes are therefore still poorly understood. Laboratory astrophysics provides complementary routes to unveil these chemical processes, but most experiments rely on combustion or plasma decomposition of molecular precursors under physical conditions far removed from those in space. To reproduce and characterize the bottom-up dust formation process, we have built an ultra-high vacuum machine combining atomic gas aggregation with advanced in situ characterization techniques. We show that carbonaceous dust analogues that formed from low-pressure gas-phase condensation of carbon atoms in a hydrogen atmosphere, in a ratio of carbon to molecular hydrogen similar to that reported for evolved stars, lead to the formation of amorphous carbon nanograins and aliphatic carbon clusters. Aromatic species and fullerenes do not form effectively under these conditions, raising implications for a revision of the chemical mechanisms taking place in circumstellar envelopes.

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