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Microbial communities in Mont Blanc snowpack with Saharan dust deposition: focus on snow microbiota

Abstract : The objective of this study is to assess the uncultured bacterial diversity in the snowpack of the Mont Blanc (MtBl) glacier containing Saharan dust deposited during four dust events over the period 2006 - 2009, by means of molecular phylogenetics. Bacterial diversity was evaluated using rybotyping and subsequent sequencing of partial (V3-V5) and full-length 16S rRNA genes. For comparison purpose we also studied following samples: MtBl snow containing no Saharan dust (by both rDNA and rRNA approaches); Saharan sand collected in Tunisia; Saharan dust collected in Grenoble (200 m a.s.l.) and recovered later on MtBl (4250 m a.s.l.). Species content and dominant phylotypes and their assigning to major divisions varied significantly in alpine snow on a MtBl glacier associated with four depositions of Saharan dust over a 3-year. Dominant phylotypes revealed are belonged to Actinobacteria, Proteobactreia, Firmicutes, Deinococcus-Thermus, Bacteroidetes and Cyanobacteria. Such variability seems to be defined more by conditions of dust transport than bacterial load from the original dust source. Overall, 15 phylotypes were recognized as potential snow colonizers. Of them, representatives of genera Massilia, Tumebacillus, Phormidium and Stigonema are most relevant findings in terms of propagation in snow. Among all identified phylotypes, 10% were categorized as HA-phylotypes based on their similarity (≥98%) with normal human microbiome representatives and 11% showed less than 90% similarity with known taxa. Sequencing of both partial (V3-V5) and full-length 16S rRNA genes permitted us to describe microbial diversity more fully and get more detailed picture.
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https://tel.archives-ouvertes.fr/tel-00641977
Contributor : Maria Chuvochina <>
Submitted on : Thursday, November 17, 2011 - 9:20:22 AM
Last modification on : Thursday, November 19, 2020 - 3:54:26 PM
Long-term archiving on: : Saturday, February 18, 2012 - 2:30:32 AM

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  • HAL Id : tel-00641977, version 1

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Maria Chuvochina. Microbial communities in Mont Blanc snowpack with Saharan dust deposition: focus on snow microbiota. Biodiversity. Université de Grenoble, 2011. Russian. ⟨tel-00641977⟩

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