Abstract：
:Aqueous solutions on Mars are theorized to contain very different ion compositions than those on Earth. To determine the effect of such solutions on typical environmental micro-organisms, which could be released from robotic spacecraft or human exploration activity, we investigated the resistance of Sphingomonas desiccabilis to brines that simulate the composition of martian aqueous environments. S. desiccabilis is a desiccation-resistant, biofilm-forming microbe found in desert crusts. The viability of cells in both planktonic and biofilm forms was measured after exposure to simulated martian brines. Planktonic cells showed a loss of viability over the course of several hours in almost all of the seven brines tested. Biofilms conferred greater resistance to all the brines, including those with low water activity and pH, but even cells in biofilms showed a complete loss of viability in <6 h in the harsher brines and in <2 days in the less harsh brines. One brine, however, allowed the microbes to maintain viability over several days, despite having a water activity and pH lower and ionic strength higher than brines that reduced viability over the same timescales, suggesting important ion-specific effects. These data show that biofilm-forming cells have a greater capacity to resist martian aqueous extremes, but that evaporative or deliquescent brines are likely to be destructive to many organisms over relatively short timescales, with implications for the habitability of Mars and for micro-organisms dispersed by robotic or human explorers.
journal_name
Astrobiologyjournal_title
Astrobiologyauthors
Stevens AH,Childers D,Fox-Powell M,Nicholson N,Jhoti E,Cockell CSdoi
10.1089/ast.2018.1840subject
Has Abstractpub_date
2019-01-01 00:00:00pages
87-98issue
1eissn
1531-1074issn
1557-8070journal_volume
19pub_type
杂志文章相关文献
ASTROBIOLOGY文献大全abstract：:Granitoids are silicic rocks that make up the majority of the continental crust, but different models arise for the origins of these rocks. One classification scheme defines different granitoid types on the basis of materials involved in the melting/crystallization process. In this end-member case, granitoids may be d...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2014.1248
更新日期：2015-07-01 00:00:00
abstract：:Lunar dust toxicity has to be evaluated in view of future manned missions to the Moon. Previous studies on lunar specimens and simulated dusts have revealed an oxidant activity assigned to HO· release. However, the mechanisms behind the reactivity of lunar dust are still quite unclear at the molecular level. In the pr...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2014.1216
更新日期：2015-05-01 00:00:00
abstract：UNLABELLED:We developed a prototype instrument called the Standoff Biofinder, which can quickly locate biological material in a 500 cm(2) area from a 2 m standoff distance with a detection time of 0.1 s. All biogenic materials give strong fluorescence signals when excited with UV and visible lasers. In addition, the lu...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2015.1400
更新日期：2016-09-01 00:00:00
abstract：:We propose a terahertz (far-infrared) circular dichroism-based life-detection technology that may provide a universal and unequivocal spectroscopic signature of living systems regardless of their genesis. We argue that, irrespective of the specifics of their chemistry, all life forms will employ well-structured, chira...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/153110703322610609
更新日期：2003-10-01 00:00:00
abstract：:This experiment was aimed at establishing, for the first time, the survival capability of lichens exposed to space conditions. In particular, the damaging effect of various wavelengths of extraterrestrial solar UV radiation was studied. The lichens used were the bipolar species Rhizocarpon geographicum and Xanthoria e...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2006.0046
更新日期：2007-06-01 00:00:00
abstract：:The emergence of an RNA entity capable of synthesizing peptides was a key prebiotic development. It is hypothesized that a precursor of the modern ribosomal exit tunnel was associated with this RNA entity (e.g., "protoribosome" or "bonding entity") from the earliest time and played an essential role. Various compounds...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2011.0692
更新日期：2012-01-01 00:00:00
abstract：:We highlight the role of COSPAR and the scientific community in defining and updating the framework of planetary protection. Specifically, we focus on Mars "Special Regions," areas where strict planetary protection measures have to be applied before a spacecraft can explore them, given the existence of environmental c...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2016.1472
更新日期：2016-02-01 00:00:00
abstract：:Polymeric compounds similar to oligonucleotides are relevant to the origin of life and particularly to the concept of an RNA world. Although short oligomers of RNA can be synthesized nonenzymatically under laboratory conditions by second-order reactions in concentrated solutions, there is no consensus on how these pol...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/15311070152757465
更新日期：2001-10-01 00:00:00
abstract：:To the astrobiologist, Enceladus offers easy access to a potential subsurface biosphere via the intermediacy of a plume of water emerging directly into space. A direct question follows: If we were to collect a sample of this plume, what in that sample, through its presence or its absence, would suggest the presence an...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2016.1611
更新日期：2017-09-01 00:00:00
abstract：:The self-assembly of simple amphiphiles like fatty acids into cell-like membranous structures suggests that such structures were available on prebiotic Earth to support the origin of cellular life. However, the composition of primitive membranes remains unclear because the physical properties of the aqueous environmen...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2009.0384
更新日期：2009-12-01 00:00:00
abstract：:Ultraviolet (UV) irradiation on the surface of Mars is an important factor that affects the survivability of microorganisms on Mars. The possibility of martian brines made from Fe2(SO4)3, MnSO4, and MgSO4 salts providing a habitable niche on Mars via attenuation of UV radiation was investigated on the bacteria Bacillu...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2020.2285
更新日期：2020-11-25 00:00:00
abstract：:In spite of the spectacular developments in our understanding of the molecular basis that underlies biological phenomena, we still lack a generally agreed-upon definition of life, but this is not for want of trying. Life is an empirical concept; and, as suggested by the many unsuccessful efforts to define it, this tas...
journal_title：Astrobiology
pub_type： 历史文章,杂志文章
doi：10.1089/ast.2010.0535
更新日期：2010-12-01 00:00:00
abstract：:Life-detection instruments on future Mars missions may use surfactant solutions to extract organic matter from samples of martian rocks. The thermal and radiation environments of space and Mars are capable of degrading these solutions, thereby reducing their ability to dissolve organic species. Successful extraction a...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2013.1105
更新日期：2014-09-01 00:00:00
abstract：:In recent years, studies have shown that there are many similarities between comets and asteroids. In some cases, it cannot even be determined to which of these groups an object belongs. This is especially true for objects found beyond the main asteroid belt. Because of the lack of comet fragments, more progress has b...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2015.1354
更新日期：2016-04-01 00:00:00
abstract：:In June 2003, the geochemical composition of geothermal fluids was determined at 9 sites in the Vulcano hydrothermal system, including sediment seeps, geothermal wells, and submarine vents. Compositional data were combined with standard state reaction properties to determine the overall Gibbs free energy (DeltaG(r) ) ...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2007.0128
更新日期：2007-12-01 00:00:00
abstract：:Abstract Technologies that enable rapid and efficient extraction of biomarker compounds from various solid matrices are a critical requirement for the successful implementation of in situ chemical analysis of the martian regolith. Here, we describe a portable subcritical water extractor that mimics multiple organic so...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2007.0154
更新日期：2008-06-01 00:00:00
abstract：:We revisit the validity of the presence of O(2) or O(3) in the atmosphere of a rocky planet as being a biosignature. Up to now, the false positive that has been identified applies to a planet during a hot greenhouse runaway, which is restricted to planets outside the habitable zone (HZ) of the star that are closer to ...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2010.0516
更新日期：2011-05-01 00:00:00
abstract：:The possible meteorite parent body origin of Earth's pregenetic nucleobases is substantiated by the guanine (G), adenine (A), and uracil (U) measured in various meteorites. Cytosine (C) and thymine (T), however, are absent in meteorites, making the emergence of an RNA and later RNA/DNA/protein world problematic. We in...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2015.1451
更新日期：2016-11-01 00:00:00
abstract：:Epsomite (MgSO(4).7H(2)O) and hexahydrite (MgSO(4).6H(2)O) are common minerals found in marine evaporite deposits, in saline lakes as precipitates, in weathering zones of coal and metallic deposits, in some soils and their efflorescences, and possibly on the surface of Europa as evaporite deposits. Thermodynamic prope...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/153110703322610708
更新日期：2003-10-01 00:00:00
abstract：:Initially, Raman spectroscopy was a specialized technique used by vibrational spectroscopists; however, due to rapid advancements in instrumentation and imaging techniques over the last few decades, Raman spectrometers are widely available at many institutions, allowing Raman spectroscopy to become a widespread analyt...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2013.1034
更新日期：2013-10-01 00:00:00
abstract：:Two terrestrial environments that have been proposed as analogs for the iron oxide precipitation in the Meridiani Planum region of Mars include the Rio Tinto precipitates and southern Utah marble concretions. Samples of two typical Utah iron oxide concretions and iron oxide precipitates in contact with biofilms from R...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2006.6.527
更新日期：2006-08-01 00:00:00
abstract：:Microbialites can have complex morphologies that preserve clues to ancient microbial ecology. However, extracting and interpreting these clues is challenging due to both the complexity of microbial structures and the difficulties of connecting morphology to microbial processes. Fenestrate microbialites from the 2521±3...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2010.0560
更新日期：2011-07-01 00:00:00
abstract：:The chemical basis of life involves more than simply the presence of biological molecules; biochemical systems embody a complex network of reactions with characteristic topological features. At the same time, chemical complexity is also present in nonbiological contexts, inviting us to clarify the relationship between...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2011.0674
更新日期：2012-01-01 00:00:00
abstract：UNLABELLED:The search for indisputable traces of life in Archean cherts is of prime importance. However, their great age and metamorphic history pose constraints on the study of molecular biomarkers. We propose a quantitative criterion to document the thermal maturity of organic matter in rocks in general, and Archean ...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2015.1392
更新日期：2016-06-01 00:00:00
abstract：:Both hydrogen and methane are consistently discharged in large quantities in hydrothermal fluids issued from ultramafic-hosted hydrothermal fields discovered along the Mid-Atlantic Ridge. Considering the vast number of these fields discovered or inferred, hydrothermal fluxes represent a significant input of H2 and CH4...
journal_title：Astrobiology
pub_type： 杂志文章,评审
doi：10.1089/ast.2014.1198
更新日期：2015-05-01 00:00:00
abstract：:Bacterial endospores in the genus Bacillus are considered good models for studying interplanetary transfer of microbes by natural or human processes. Although spore survival during transfer itself has been the subject of considerable study, the fate of spores in extraterrestrial environments has received less attentio...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2005.5.536
更新日期：2005-08-01 00:00:00
abstract：UNLABELLED:Fluid inclusions trapped in ancient halite can contain a community of halophilic prokaryotes and eukaryotes that inhabited the surface brines from which the halite formed. Long-term survival of bacteria and archaea and preservation of DNA have been reported from halite, but little is known about the distribu...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2015.1397
更新日期：2016-06-01 00:00:00
abstract：:The thermal springs Trollosen and Fisosen, located on the High Arctic archipelago Svalbard, discharge saline groundwaters rich in hydrogen sulfide and ammonium through a thick layer of permafrost. Large amounts of biomass that consist of filamentous microorganisms containing sulfur granules, as analyzed with energy di...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2010.0551
更新日期：2011-09-01 00:00:00
abstract：:Materials blasted into space from the surface of early Earth may preserve a unique record of our planet's early surface environment. Armstrong et al. (2002) pointed out that such materials, in the form of terrestrial meteorites, may exist on the Moon and be of considerable astrobiological interest if biomarkers from e...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2007.0215
更新日期：2008-04-01 00:00:00
abstract：:The primary objective of NASA's Mars Science Laboratory (MSL) mission, which will launch in 2011, is to characterize the habitability of a site on Mars through detailed analyses of the composition and geological context of surface materials. Within the framework of established mission goals, we have evaluated the valu...
journal_title：Astrobiology
pub_type： 杂志文章
doi：10.1089/ast.2010.0491
更新日期：2010-09-01 00:00:00
