This research aimed to investigate the viability and biodiversity of microbial communities within ancient Arctic permafrost after exposure to a gamma-radiation dose of 100 kGy at low temperature (- 50 °C), low pressure (1 Torr) and dehydration conditions. The main objective was to assess the possibility for long-term survival of Earth-bound microorganisms in the subsurface of Martian regolith or inside small space bodies at constant absorption and accumulation of the gamma radiation dose. Investigated microbial communities had shown high resistance to a simulated Martian environment.
View Article and Find Full Text PDFPhilos Trans A Math Phys Eng Sci
January 2016
This article examines the question of the possible existence of microbial life inhabiting the subglacial Lake Vostok buried beneath a 4 km thick Antarctic ice sheet. It represents the results of analysis of the only available frozen lake water samples obtained upon the first lake entry and subsequent re-coring the water frozen within the borehole. For comparison, results obtained by earlier molecular microbiological studies of accretion ice are included in this study, with the focus on thermophiles and an unknown bacterial phylotype.
View Article and Find Full Text PDFMicroorganisms uplifted during dust storms survive long-range transport in the atmosphere and could colonize high-altitude snow. Bacterial communities in alpine snow on a Mont Blanc glacier, associated with four depositions of Saharan dust during the period 2006-2009, were studied using 16S rRNA gene sequencing and flow cytometry. Also, sand from the Tunisian Sahara, Saharan dust collected in Grenoble and Mont Blanc snow containing no Saharan dust (one sample of each) were analyzed.
View Article and Find Full Text PDFDecontamination of ice cores is a critical issue in phylogenetic studies of glacial ice and subglacial lakes. At the Vostok drill site, a total of 3650 m of ice core have now been obtained from the East Antarctic ice sheet. The ice core surface is coated with a hard-to-remove film of impure drilling fluid comprising a mixture of aliphatic and aromatic hydrocarbons and foranes.
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