Suchergebnisse

Although biomineralization in plants is an important area of research, there is very limited information. In this work, we report the location of Na, K, Ca, Mg and Fe biominerals in Sarcocornia pruinosa (Chenopodiacaeae), a halophyte species growing in the estuarine area of Río Tinto, an extreme acidic environment. The estuarine soils of the Tinto basin are characterized by slightly acidic pH and high concentrations of ions. They are exposed to Atlantic Ocean tides that contribute to the increase in pH, Na and Mg concentrations. The aim of this work was to characterize the elemental composition and to identify the biominerals detected in cell tissues of S. pruinosa. Analytical techniques, such as ICP-MS (Inductively coupled plasma mass spectrometry), XRD and microscopy such as OM (optical microscopy) with histochemical staining, SEM and TEM (scanning and transmission electronic microscopy) coupled with EDX (energy dispersive X-ray) were carried out to analyze the plant tissues of S. pruinosa and characterize the detected biominerals. The elemental composition in succulent stems and seeds of S. pruinosa showed high values of Na and K followed by Ca, Mg and Fe. The presence of halite, sylvite, weddellite, glushinskite and Fe oxides biominerals in this halophyte species is reported. Our data suggest the importance of vegetation in the biogeochemical cycles in estuarine areas. ; This research was funded by the Ministerío de Economía y Competitividad (MEC, Spanish Government).grant number CGL2015 66-242 R. ; Peer reviewed

The Dallol geothermal area in the northern part of the Danakil Depression (up to 124–155 meter below sea level) is deemed one of the most extreme environments on Earth. The area is notable for being part of the Afar Depression, an incipient seafloor-spreading center located at the triple junction, between Nubian, Somali and Arabian plates, and for hosting environments at the very edge of natural physical-chemical extremities. The northern part of the Danakil Depression is dominated by the Assale salt plain (an accumulation of marine evaporite deposits) and hosts the Dallol volcano. Here, the interaction between the evaporitic deposit and the volcanisms have created the unique Dallol hot springs, which are highly acidic (pH ~ 0) and saline (saturation) with maximum temperatures ranging between 90 and 109 °C. Here we report for the first time evidence of life existing with these hot springs using a combination of morphological and molecular analyses. Ultra-small structures are shown to be entombed within mineral deposits, which are identified as members of the Order Nanohaloarchaea. The results from this study suggest the microorganisms can survive, and potential live, within this extreme environment, which has implications for understanding the limits of habitability on Earth and on (early) Mars ; Europlanet 2020 RI received funding from the European Union's Horizon 2020 research and innovation program under Grant Agreement No 654208

The Dallol geothermal area in the northern part of the Danakil Depression (up to 124–155 meter below sea level) is deemed one of the most extreme environments on Earth. The area is notable for being part of the Afar Depression, an incipient seafloor-spreading center located at the triple junction, between Nubian, Somali and Arabian plates, and for hosting environments at the very edge of natural physical-chemical extremities. The northern part of the Danakil Depression is dominated by the Assale salt plain (an accumulation of marine evaporite deposits) and hosts the Dallol volcano. Here, the interaction between the evaporitic deposit and the volcanisms have created the unique Dallol hot springs, which are highly acidic (pH ~ 0) and saline (saturation) with maximum temperatures ranging between 90 and 109 °C. Here we report for the first time evidence of life existing with these hot springs using a combination of morphological and molecular analyses. Ultra-small structures are shown to be entombed within mineral deposits, which are identified as members of the Order Nanohaloarchaea. The results from this study suggest the microorganisms can survive, and potential live, within this extreme environment, which has implications for understanding the limits of habitability on Earth and on (early) Mars. ; European Union's Horizon 2020 research and innovation program under Grant Agreement No 654208

Insertion sequences (ISs) are ubiquitous and abundant mobile genetic elements in prokaryotic genomes. ISs often encode only one protein, the transposase, which catalyzes their transposition. Recent studies have shown that transposases of many different IS families interact with the β sliding clamp, a DNA replication factor of the host. However, it was unclear to what extent this interaction limits or favors the ability of ISs to colonize a chromosome from a phylogenetically-distant organism, or if the strength of this interaction affects the transposition rate. Here we describe the proliferation of a member of the IS1634 family in Acidiphilium over ~600 generations of cultured growth. We demonstrate that the purified transposase binds to the β sliding clamp of Acidiphilium, Leptospirillum and E. coli. Further, we also demonstrate that the Acidiphilium IS1634 transposase binds to the archaeal sliding clamp (PCNA) from Methanosarcina, and that the transposase encoded by Methanosarcina IS1634 binds to Acidiphilium β. Finally, we demonstrate that increasing the strength of the interaction between β and transposase results in a higher transposition rate in vivo. Our results suggest that the interaction could determine the potential of ISs to be mobilized in bacterial populations and also their ability to proliferate within chromosomes ; This work was funded by the Subdirección General de Proyectos de Investigación of the Spanish Ministry for Economy and Competitiveness Grants No. CGL2010-17384 and AYA2011-24803, and by the European Research Council (ERC) Advanced Grant No. 250350 (IPBSL). HDM has a FPI fellowship from the Spanish Government

Insertion sequences (ISs) are ubiquitous and abundant mobile genetic elements in prokaryotic genomes. ISs often encode only one protein, the transposase, which catalyzes their transposition. Recent studies have shown that transposases of many different IS families interact with the β sliding clamp, a DNA replication factor of the host. However, it was unclear to what extent this interaction limits or favors the ability of ISs to colonize a chromosome from a phylogenetically-distant organism, or if the strength of this interaction affects the transposition rate. Here we describe the proliferation of a member of the IS1634 family in Acidiphilium over ~600 generations of cultured growth. We demonstrate that the purified transposase binds to the β sliding clamp of Acidiphilium, Leptospirillum and E. coli. Further, we also demonstrate that the Acidiphilium IS1634 transposase binds to the archaeal sliding clamp (PCNA) from Methanosarcina, and that the transposase encoded by Methanosarcina IS1634 binds to Acidiphilium β. Finally, we demonstrate that increasing the strength of the interaction between β and transposase results in a higher transposition rate in vivo. Our results suggest that the interaction could determine the potential of ISs to be mobilized in bacterial populations and also their ability to proliferate within chromosomes. ; This work was funded by the Subdirección General de Proyectos de Investigación of the Spanish Ministry for Economy and Competitiveness Grants No. CGL2010-17384 and AYA2011-24803, and by the European Research Council (ERC) Advanced Grant No. 250350 (IPBSL). HDM has a FPI fellowship from the Spanish Government. ; Peer reviewed

The photocatalytic elimination of microorganisms from indoor air in realistic conditions and the feasibility of simultaneous elimination of chemical contaminants have been studied at laboratory scale. Transparent polymeric monoliths have been coated with sol-gel TiO 2 films and used as photocatalyst to treat real indoor air in a laboratory-scale single-step annular photocatalytic reactor. The analytical techniques used to characterize the air quality and analyze the results of the photocatalytic tests were: colony counting, microscopy and PCR with subsequent sequencing for microbial quantification and identification; automated thermal desorption coupled to gas chromatography with mass spectrometry detection for chemical analysis. The first experiments performed proved that photocatalysis based on UVA-irradiated TiO 2 for the reduction of the concentration of bacteria in the air could compete with the conventional photolytic treatment with UVC radiation, more expensive and hazardous. Simultaneously to the disinfection, the concentration of volatile organic compounds was greatly reduced, which adds value to this technology for real applications. The fungal colony number was not apparently modified. © 2012 Elsevier Ltd. ; Spanish Government for financial support (TRA2009_0262_01 (TRACE) and CTM2008-06876-CO2-01/TECNO (IndoorAir)) ; Peer Reviewed

Viking missions reported adverse conditions for life in Mars surface. High hydrogen signal obtained by Mars orbiters has increased the interest in subsurface prospection as putative protected Mars environment with life potential. Permafrost has attracted considerable interest from an astrobiological point of view due to the recently reported results from the Mars exploration rovers. Considerable studies have been developed on extreme ecosystems and permafrost in particular, to evaluate the possibility of life on Mars and to test specific automated life detection instruments for space missions. The biodiversity of permafrost located on the Bering Land Bridge National Preserve has been studied as an example of subsurface protected niche of astrobiological interest. Different conventional (enrichment and isolation) and molecular ecology techniques (cloning, fluorescence >in situ> probe hybridization, FISH) have been used for isolation and bacterial identification. ; The expedition to Imuruk Lake was supported by Centro de Astrobiologia-INTA (Spain). The laboratory experimental procedures were supported by Grant AYA 2010–2013 "Desarrollo de Tecnología para la identificación de vida de forma automática" from the Spanish Government. ; Peer Reviewed

Viking missions reported adverse conditions for life in Mars surface. High hydrogen signal obtained by Mars orbiters has increased the interest in subsurface prospection as putative protected Mars environment with life potential. Permafrost has attracted considerable interest from an astrobiological point of view due to the recently reported results from the Mars exploration rovers. Considerable studies have been developed on extreme ecosystems and permafrost in particular, to evaluate the possibility of life on Mars and to test specific automated life detection instruments for space missions. The biodiversity of permafrost located on the Bering Land Bridge National Preserve has been studied as an example of subsurface protected niche of astrobiological interest. Different conventional (enrichment and isolation) and molecular ecology techniques (cloning, fluorescence "in situ" probe hybridization, FISH) have been used for isolation and bacterial identification ; The expedition to Imuruk Lake was supported by Centro de Astrobiología-INTA (Spain). The laboratory experimental procedures were supported by Grant AYA 2010–20213 "Desarrollo de Tecnología para la identificación de vida de forma automática" from the Spanish Government