Author's personal copy Searching for life in extreme environments relevant to Jovian’s Europa: Lessons from subglacial ice studies
The objective was to estimate the genuine microbial content of ice samples from refrozen water (accretion ice) from the subglacial Lake Vostok (Antarctica) buried beneath the 4-km thick East Antarctic ice sheet. The samples were extracted by heavy deep ice drilling from 3659 m below the surface. Hig...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.640.6162 2023-05-15T14:04:15+02:00 Author's personal copy Searching for life in extreme environments relevant to Jovian’s Europa: Lessons from subglacial ice studies Sergey A. Bulat A Irina A. Alekhina A Dominique Marie B Jean Martins D Jean Robert Petit C The Pennsylvania State University CiteSeerX Archives 2010 http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.640.6162 en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.640.6162 Metadata may be used without restrictions as long as the oai identifier remains attached to it. text 2010 ftciteseerx 2016-01-08T15:56:43Z The objective was to estimate the genuine microbial content of ice samples from refrozen water (accretion ice) from the subglacial Lake Vostok (Antarctica) buried beneath the 4-km thick East Antarctic ice sheet. The samples were extracted by heavy deep ice drilling from 3659 m below the surface. High pressure, a low carbon and chemical content, isolation, complete darkness and the probable excess of oxygen in water for millions of years characterize this extreme environment. A decontamination protocol was first applied to samples selected for the absence of cracks to remove the outer part contaminated by handling and drilling fluid. Preliminary indications showed the accretion ice samples to be almost gas free with a low impurity content. Flow cytometry showed the very low unevenly distributed biomass while repeated microscopic observations were unsuccessful. We used strategies of Ancient DNA research that include establishing contaminant databases and criteria to validate the amplification results. To date, positive results that passed the artifacts and contaminant databases have been obtained for a pair of bacterial phylotypes only in accretion ice samples featured by some bedrock sediments. The phylotypes included the chemolithoautotrophic thermophile Hydrogenophilus thermoluteolus and one unclassified phylotype. Combined with geochemical and geophysical considerations, our results suggest the presence of a deep biosphere, possibly thriving within some active faults of the bedrock encircling the subglacial lake, where the temperature is as high as 50 C and in situ hydrogen is probably present. Text Antarc* Antarctic Antarctica Ice Sheet Unknown Antarctic East Antarctic Ice Sheet Lake Vostok ENVELOPE(106.000,106.000,-77.500,-77.500) |
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English |
description |
The objective was to estimate the genuine microbial content of ice samples from refrozen water (accretion ice) from the subglacial Lake Vostok (Antarctica) buried beneath the 4-km thick East Antarctic ice sheet. The samples were extracted by heavy deep ice drilling from 3659 m below the surface. High pressure, a low carbon and chemical content, isolation, complete darkness and the probable excess of oxygen in water for millions of years characterize this extreme environment. A decontamination protocol was first applied to samples selected for the absence of cracks to remove the outer part contaminated by handling and drilling fluid. Preliminary indications showed the accretion ice samples to be almost gas free with a low impurity content. Flow cytometry showed the very low unevenly distributed biomass while repeated microscopic observations were unsuccessful. We used strategies of Ancient DNA research that include establishing contaminant databases and criteria to validate the amplification results. To date, positive results that passed the artifacts and contaminant databases have been obtained for a pair of bacterial phylotypes only in accretion ice samples featured by some bedrock sediments. The phylotypes included the chemolithoautotrophic thermophile Hydrogenophilus thermoluteolus and one unclassified phylotype. Combined with geochemical and geophysical considerations, our results suggest the presence of a deep biosphere, possibly thriving within some active faults of the bedrock encircling the subglacial lake, where the temperature is as high as 50 C and in situ hydrogen is probably present. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Sergey A. Bulat A Irina A. Alekhina A Dominique Marie B Jean Martins D Jean Robert Petit C |
spellingShingle |
Sergey A. Bulat A Irina A. Alekhina A Dominique Marie B Jean Martins D Jean Robert Petit C Author's personal copy Searching for life in extreme environments relevant to Jovian’s Europa: Lessons from subglacial ice studies |
author_facet |
Sergey A. Bulat A Irina A. Alekhina A Dominique Marie B Jean Martins D Jean Robert Petit C |
author_sort |
Sergey A. Bulat A |
title |
Author's personal copy Searching for life in extreme environments relevant to Jovian’s Europa: Lessons from subglacial ice studies |
title_short |
Author's personal copy Searching for life in extreme environments relevant to Jovian’s Europa: Lessons from subglacial ice studies |
title_full |
Author's personal copy Searching for life in extreme environments relevant to Jovian’s Europa: Lessons from subglacial ice studies |
title_fullStr |
Author's personal copy Searching for life in extreme environments relevant to Jovian’s Europa: Lessons from subglacial ice studies |
title_full_unstemmed |
Author's personal copy Searching for life in extreme environments relevant to Jovian’s Europa: Lessons from subglacial ice studies |
title_sort |
author's personal copy searching for life in extreme environments relevant to jovian’s europa: lessons from subglacial ice studies |
publishDate |
2010 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.640.6162 |
long_lat |
ENVELOPE(106.000,106.000,-77.500,-77.500) |
geographic |
Antarctic East Antarctic Ice Sheet Lake Vostok |
geographic_facet |
Antarctic East Antarctic Ice Sheet Lake Vostok |
genre |
Antarc* Antarctic Antarctica Ice Sheet |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.640.6162 |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766275287793795072 |