Search results for "Extreme environment"
showing 10 items of 23 documents
Primary Structure of Selected Archaeal Mesophilic and Extremely Thermophilic Outer Surface Layer Proteins
2002
The archaea are recognized as a separate third domain of life together with the bacteria and eucarya. The archaea include the methanogens, extreme halophiles, thermoplasmas, Sulfate reducers and Sulfur metabolizing thermophiles, which thrive in different habitats such as anaerobic niches, salt lakes, and marine hydrothermals systems and continental solfataras. Many of these habitats represent extreme environments in respect to temperature, osmotic pressure and pH-values and remind on the conditions of the early earth. The cell envelope structures were one of the first biochemical characteristics of archaea studied in detail. The most common archaeal cell envelope is composed of a single cry…
Multidisciplinary integrated field campaign to an acidic Martian Earth analogue with astrobiological interest: Rio Tinto
2011
Recently reported results from latest Mars Orbiters and Rovers missions are transforming our opinion about the red planet. That dry and inhospitable planet reported in the past is becoming a wetter planet with high probabilities of water existence in the past. Nowadays, some results seem to indicate the presence of water beneath the Mars surface. But also mineralogy studies by NASA Opportunity Rover report iron oxides and hydroxides precipitates on Endurance Crater. Sedimentary deposits have been identified at Meridiani Planum. These deposits must have generated in a dune aqueous acidic and oxidizing environment. Similarities appear when we study Rio Tinto, and acidic river under the control…
Geothermal Gases Shape the Microbial Community of the Volcanic Soil of Pantelleria, Italy
2020
The Favara Grande nature reserve on the volcanic island of Pantelleria (Italy) is known for its geothermal gas emissions and high soil temperatures. These volcanic soil ecosystems represent “hot spots” of greenhouse gas emissions. The unique community might be shaped by the hostile conditions in the ecosystem, and it is involved in the cycling of elements such as carbon, hydrogen, sulfur, and nitrogen. Our metagenome study revealed that most of the microorganisms in this extreme environment are only distantly related to cultivated bacteria. The results obtained profoundly increased the understanding of these natural hot spots of greenhouse gas production/degradation and will help to enrich …
Bioprospecting the solar panel microbiome: High-throughput screening for antioxidant bacteria in a caenorhabditis elegansModel
2018
Microbial communities that are exposed to sunlight typically share a series of adaptations to deal with the radiation they are exposed to, including efficient DNA repair systems, pigment production and protection against oxidative stress, which makes these environments good candidates for the search of novel antioxidant microorganisms. In this research project, we isolated potential antioxidant pigmented bacteria from a dry and highly-irradiated extreme environment: solar panels. High-throughput in vivo assays using Caenorhabditis elegans as an experimental model demonstrated the high antioxidant and ultraviolet-protection properties of these bacterial isolates that proved to be rich in car…
The florula of hypersaline habitats in Central Mediterranean and its biological traits
2018
Salinity is one of the most widespread soil degradation processes. In fact in saline soils uneven temporal and spatial water distribution and localized high concentration of salts occur, characterizing restricted habitats where most of the present organisms are halophilic or salt tolerant. Soils could be classified hypersaline when salt concentration exceeds certain thresholds (1, 2). For this study were analysed 10 hypersaline soil localities from Sicily (Birgi, Isola Lunga, Salinelle Marsala, Capo Feto, Piana del Signore, Vendicari) and Tunisia (Qurba, Khniss, Ras Dimas, Chebba). These areas are temporarily flooded in autumn and winter, with longer permanence of water in some zones. Salt …
Soil fungal community composition does not alter along a latitudinal gradient through the maritime and sub-Antarctic
2012
We investigated the relationships between fungal community composition, latitude and a range of physicochemical parameters in 58 soils sampled from a 2370 km latitudinal gradient between South Georgia (54 S, 38 W) in the sub-Antarctic and Mars Oasis (72 S, 68 W) on Alexander Island in the southern maritime Antarctic. Our study, which is based on approximately ten times the number of samples used in previous similar studies, indicates that latitude and its associated environmental parameters are not related to fungal community composition. Significant changes in the composition of soil fungal communities were observed in relation to gradients of the ratio of total organic carbon to nitrogen,…
Desiccation by Exposure to Space Vacuum or Extremely Dry Deserts: Effect on Microorganisms
2003
General Limits of Growth at Low Water Activities Dormant Life Molecular Events Induced by Desiccation Survival at Extremely Low Water Activity Survival Under Extremely Dry Desert Conditions Keywords: anhydrobiosis; desiccation; extreme environments; freeze-drying; panspermia thesis; space: survival in space; space vacuum; water activity
Social, occupational and cultural adaptation in Antarctica
2017
International audience; Objectives & Method: This study investigated psychological, social, occupational and cultural variables in adaptation to a one-year wintering in Antarctica with 13 international participants. Results & Conclusion: These psychosocial issues have important implications for pre-mission selection and training, monitoring and support of crews during the mission and post-mission readaptation highlighting the role of psychologists in stressful and extreme situations.
Warm and wet: robust lipase-producing bacteria from the indoor environment
2017
Lipases are key biocatalysts with important biotechnological applications. With the aim of isolating robust lipolytic microbial strains, we have analyzed the bacterial communities inhabiting two domestic extreme environments: a thermophilic sauna and a dishwasher filter. Scanning electron microscopy revealed biofilm-forming and scattered microorganisms in the sauna and dishwasher sample, respectively. A culture-independent approach based on 16S rRNA analysis indicated a high abundance of Proteobacteria in the sauna sample; and, a large amount of Proteobacteria, Firmicutes, Cyanobacteria and Actinobacteria in the dishwasher filter. With a culture-dependent approach, we isolated 48 bacterial …
The first successful crystallization of a prokaryotic extremely thermophilic outer surface layer glycoprotein
1999
AbstractMethanoihermus fervidusbelongs to the group of hyperthermophilic Archaea. The Archaea comprise organisms that live under environmental extremes, like high temperature, lowpH value or high salt concentration. The outer surface of the pseudomurein sacculi of the cells ofMethanothermus fervidusis covered by glycoprotein subunits (S-layer) directly exposed to the extreme environment. The elucidation of the crystal structure of this surface glycoprotein may provide important information on the survival strategies of these unusual micro-organisms. Before our investigations neither three-dimensional crystals have been obtained nor X-ray analyses were performed. Only electron microscopic an…