title: Interactions between snow chemistry, mercury inputs and microbial population dynamics in an Arctic snowpack.
abstract: We investigated the interactions between snowpack chemistry, mercury (Hg) contamination and microbial community structure and function in Arctic snow. Snowpack chemistry (inorganic and organic ions) including mercury (Hg) speciation was studied in samples collected during a two-month field study in a high Arctic site, Svalbard, Norway (79 °N). Shifts in microbial community structure were determined by using a 16S rRNA gene phylogenetic microarray. We linked snowpack and meltwater chemistry to changes in microbial community structure by using co-inertia analyses (CIA) and explored changes in community function due to Hg contamination by q-PCR quantification of Hg-resistance genes in metagenomic samples. Based on the CIA, chemical and microbial data were linked (p = 0.006) with bioavailable Hg (BioHg) and methylmercury (MeHg) contributing significantly to the ordination of samples. Mercury was shown to influence community function with increases in merA gene copy numbers at low BioHg levels. Our results show that snowpacks can be considered as dynamic habitats with microbial and chemical components responding rapidly to environmental changes.
authors.affiliation: Environmental Microbial Genomics, Laboratoire Ampere, CNRS, Ecole Centrale de Lyon, Université de Lyon, Ecully, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Larose
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Prestat
authors.forename: Sébastien
authors.initials: S
authors.lastname: Cecillon
authors.forename: Sibel
authors.initials: S
authors.lastname: Berger
authors.forename: Cédric
authors.initials: C
authors.lastname: Malandain
authors.forename: Delina
authors.initials: D
authors.lastname: Lyon
authors.forename: Christophe
authors.initials: C
authors.lastname: Ferrari
authors.forename: Dominique
authors.initials: D
authors.lastname: Schneider
authors.forename: Aurélien
authors.initials: A
authors.lastname: Dommergue
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Vogel
mesh_terms: D001110:Arctic Regions; D004784:Environmental Monitoring; D018628:Gene Dosage; D006863:Hydrogen-Ion Concentration; D008628:Mercury / Q000032:analysis* / Q000737:chemistry; D056265:Microbial Interactions; D009584:Nitrogen / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000737:chemistry / Q000235:genetics; D012914:Snow / Q000737:chemistry* / Q000382:microbiology; D013455:Sulfur / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D014871:Water Microbiology
chemical_list: D012336:RNA, Ribosomal, 16S; D013455:Sulfur; D008628:Mercury; D009584:Nitrogen