Water activity in Venus’s uninhabitable clouds and other planetary atmospheres

Nature Astronomy, Год журнала: 2021, Номер 5(7), С. 665 - 675

Опубликована: Июнь 28, 2021

Язык: Английский

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Trehalose promotes biological fitness of fungi

Fungal Biology, Год журнала: 2024, Номер 128(8), С. 2381 - 2389

Опубликована: Март 16, 2024

Язык: Английский

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NaCl-saturated brines are thermodynamically moderate, rather than extreme, microbial habitats

FEMS Microbiology Reviews, Год журнала: 2018, Номер 42(5), С. 672 - 693

Опубликована: Июнь 8, 2018

NaCl-saturated brines such as saltern crystalliser ponds, inland salt lakes, deep-sea and liquids-of-deliquescence on halite are commonly regarded a paradigm for the limit of life Earth. There are, however, other habitats that thermodynamically more extreme. Typically, environments contain all domains perform complete biogeochemical cycling. Despite their reduced water activity, ∼0.755 at 5 M NaCl, some halophiles belonging to Archaea Bacteria exhibit optimum growth/metabolism in these brines. Furthermore, recognised water-activity microbial function, ∼0.585 strains fungi, lies far below 0.755. Other biophysical constraints biosphere (temperatures >121°C; pH > 12; high chaotropicity; e.g. ethanol >18.9% w/v (24% v/v) MgCl2 >3.03 M) can prevent any cellular metabolism or ecosystem function. By contrast, biomass-dense, metabolically diverse, highly active complex ecosystems; this underscores moderate character. Here, we survey evidence biologically permissive, fertile mid-range rather than Indeed, were NaCl sufficiently soluble, might grow concentrations up 8 M. It may be finite solubility has stabilised genetic composition halophile populations limited action natural selection driving evolution towards greater xerophilicity. Further implications considered origin(s) aspects astrobiology.

Язык: Английский

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Environmental distribution and genetic diversity of vegetative compatibility groups determine biocontrol strategies to mitigate aflatoxin contamination of maize by A spergillus flavus

Microbial Biotechnology, Год журнала: 2015, Номер 9(1), С. 75 - 88

Опубликована: Окт. 27, 2015

Summary Maize infected by aflatoxin‐producing A spergillus flavus may become contaminated with aflatoxins, and as a result, threaten human health, food security farmers' income in developing countries where maize is staple. Environmental distribution genetic diversity of . can influence the effectiveness atoxigenic isolates mitigating aflatoxin contamination. However, such information has not been used to facilitate selection deployment isolates. total 35 isolated from samples collected three agro‐ecological zones N igeria were this study. Ecophysiological characteristics, determined identify vegetative compatibility groups ( VCGs ). The generated data inform native mitigate contamination maize. In co‐inoculation toxigenic isolates, reduced grain > 96%. 25 inferred based on complementation tests involving nitrate non‐utilizing nit − ) mutants. To determine across zones, 832 mutants 52 locations 11 administrative districts paired one self‐complementary auxotroph tester‐pair for each VCG Atoxigenic accounted 81.1% 153 positive complementations recorded. Genetic was highest derived savannah zone H = 2.61) compared southern G uinea 1.90) northern 0.94) zones. richness 2.60) evenness E 5 0.96) high all Ten (40%) had members restricted original location isolation, whereas 15 (60%) located between source isolation distance 400 km away. present study identified widely distributed AV 0222, 3279, 3304 16127, whose be deployed region‐wide biocontrol reduce

Язык: Английский

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Stress-free microbes lack vitality

Fungal Biology, Год журнала: 2018, Номер 122(6), С. 379 - 385

Опубликована: Апрель 7, 2018

Язык: Английский

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Glycerol enhances fungal germination at the water‐activity limit for life

Environmental Microbiology, Год журнала: 2016, Номер 19(3), С. 947 - 967

Опубликована: Сен. 15, 2016

Summary For the most‐extreme fungal xerophiles, metabolic activity and cell division typically halts between 0.700 0.640 water (approximately 70.0–64.0% relative humidity). Here, we investigate whether glycerol can enhance xerophile germination under acute water‐activity regimes, using an experimental system which represents biophysical limit of Earth's biosphere. Spores from a variety species, including Aspergillus penicillioides , Eurotium halophilicum Xerochrysium xerophilum (formerly Chrysosporium ) Xeromyces bisporus were produced by cultures growing on media supplemented with (and contained up to 189 mg g dry spores −1 ). The ability these germinate, kinetics germination, then determined range designed recreate stresses experienced in microbial habitats or anthropogenic systems (with water‐activities 0.765 0.575). A. amstelodami E. X. occurred at lower than previously recorded (0.640, 0.685, 0.651, 0.664 0.637 respectively). In addition, low substantially faster those reported previously. Extrapolations indicated theoretical minima below values; as 0.570 for . Glycerol is present high concentrations (up molar levels) many types habitat. We discuss likely role expanding function relation temporal constraints location findings here have also critical implications understanding extremes biosphere; potency disease‐causing microorganisms; biotechnologies that operate limits function.

Язык: Английский

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Microbiome and ecology of a hot spring-microbialite system on the Trans-Himalayan Plateau

Scientific Reports, Год журнала: 2020, Номер 10(1)

Опубликована: Апрель 3, 2020

Little is known about life in the boron-rich hot springs of Trans-Himalayas. Here, we explore geomicrobiology a 4438-m-high spring which emanates ~70 °C-water from boratic microbialite called Shivlinga. Due to low atmospheric pressure, vent-water close boiling point so can entropically destabilize biomacromolecular systems. Starting vent, Shivlinga's was revealed along thermal gradients an outflow-channel and progressively-drying mineral matrix that has no running water; ecosystem constraints were then considered relation those comparable environments. The spring-water chemistry sinter mineralogy dominated by borates, sodium, thiosulfate, sulfate, sulfite, sulfide, bicarbonate, other macromolecule-stabilizing (kosmotropic) substances. Microbial diversity high both hydrothermal gradients. Bacteria, Eukarya Archaea constituted >98%, ~1% <1% microbiome, respectively. Temperature constrained biodiversity at ~50 °C ~60 °C, but not below 46 °C. Along each gradient, vent-to-apron trajectory, communities Aquificae/Deinococcus-Thermus, Chlorobi/Chloroflexi/Cyanobacteria, finally Bacteroidetes/Proteobacteria/Firmicutes. Interestingly, sites >45 inhabited phylogenetic relatives taxa for laboratory growth highlights possibility system's kosmotrope-dominated mitigates against biomacromolecule-disordering effects its water.

Язык: Английский

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Water is a preservative of microbes

Microbial Biotechnology, Год журнала: 2021, Номер 15(1), С. 191 - 214

Опубликована: Дек. 22, 2021

Water is the cellular milieu, drives all biochemistry within Earth's biosphere and facilitates microbe-mediated decay processes. Instead of reviewing these topics, current article focuses on activities water as a preservative-its capacity to maintain long-term integrity viability microbial cells-and identifies mechanisms by which this occurs. provides for, maintains, structures; buffers against thermodynamic extremes, at various scales; can mitigate events that are traumatic cell membrane, such desiccation-rehydration, freeze-thawing thermal shock; prevents dehydration otherwise exacerbate oxidative damage; mitigates biocidal factors (in some circumstances reducing ultraviolet radiation diluting solute stressors or toxic substances); effective electrostatic screening so damage intense fields ions. In addition, retained in desiccated cells (historically referred 'bound' water) plays key roles biomacromolecular structures their interactions even for fully hydrated cells. Assuming components membrane chemically stable least repairable, environment fairly constant, molecules apparently geometries over very long periods provided configurations represent thermodynamically states. The spores vegetative many microbes survive longer presence vapour-phase (at moderate-to-high relative humidities) than under more-arid conditions. There several large bodies water, when cooled during subzero weather conditions remain liquid state thus preventing potentially dangerous (freeze-thaw) transitions microbiome. Microbial life be preserved pure freshwater systems, seawater, brines, ice/permafrost, sugar-rich aqueous milieux according laboratory-based studies carried out years decades natural environments have yielded thousands, (for hypersaline fluid inclusions mineralized NaCl) hundreds millions, old. term preservative has often been restricted those substances used extend shelf foods (e.g. sodium benzoate, nitrites sulphites) conserve dead organisms, ethanol formaldehyde. For living microorganisms however, ultimate may actually water. Implications role discussed with reference ecology halophiles, human pathogens other microbes; food science; biotechnology; biosignatures aspects astrobiology; large-scale release/reactivation caused global climate change.

Язык: Английский

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Temperature, water activity and pH during conidia production affect the physiological state and germination time of Penicillium species

International Journal of Food Microbiology, Год журнала: 2016, Номер 241, С. 151 - 160

Опубликована: Окт. 18, 2016

Язык: Английский

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Fungal stress biology: a preface to the Fungal Stress Responses special edition

Current Genetics, Год журнала: 2015, Номер 61(3), С. 231 - 238

Опубликована: Июнь 26, 2015

Язык: Английский

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