Bacterial characterization of the snow cover at Spitzberg, Svalbard

Abstract

A sampling campaign was organized during spring 2004 in Spitzberg, Svalbard, in the area around the scientific base of Ny-Alesund, to characterize the snow pack bacterial population. Total bacteria counts were established by 4',6-diamino-2-phenylindole (DAPI) in the seasonal snow pack bordering the sea. On the sea shore, bacterial concentration was about 6 x 10(4) cells mL(-1), without any significant variation according to depth. In the accumulation snow layer of the glacier, concentrations were about 2 x 10(4 )cells mL(-1), except in the 2003 summer layer, where it reached 2 x 10(5) cells mL(-1), as the result of cell multiplication allowed by higher temperature and snow melting. Strains isolated from the seasonal snow pack were identified from their 16S rRNA gene sequences, and lodged in GenBank. They belong to the Alphaproteobacteria, Betaproteobacteria and Gammaproteobacteria, Firmicutes and Actinobacteria. They are closely related to cold environment bacteria, as revealed by phylogenetic tree constructions, and two appear to be of unknown affiliation. Using 1H nuclear magnetic resonance, it was shown that these isolates have the capacity to degrade organic compounds found in Arctic snow (propionate, acetate and formate), and this can allow them to develop when snow melts, and thus to be actively involved in snow chemistry.

Potential sources of microbial colonizers in an initial soil ecosystem after retreat of an alpine glacier

“…One aim of this study was to identify whether potential microbial colonizers of mineral debris were deposited from the atmosphere. Microorganisms travelling through the atmosphere represent perfect immigrant candidates (Pearce et al, 2009) to establish in nutrient-poor soils formed after glacier retreat because they can thrive and remain active under high UV exposure, osmotic stress and C depletion (Amato et al, 2007;Šantl-Temkiv et al, 2012;Šantl-Temkiv et al, 2013). We found, however, that atmospheric bacterial and fungal communities deposited in the Damma glacier catchment were different from those of soils.…”

The fate of mercury in Arctic terrestrial and aquatic ecosystems, a review

“…[60] There is good evidence that microbes are metabolically active at subzero temperatures in snow [54,83,84] and sea ice. [85] This raises the question of whether deposited Hg II can be actively transformed into other species (GEM or MeHg) by microbes in the Arctic cryosphere (snow, sea ice, freshwater ice).…”

“…Regardless of the processes that control Hg retention in snow and ice it is obvious that the fraction of AMDE-deposited atmospheric Hg that is highly photoreactive may not be bioavailable to the microbes thriving in snow in polar spring. [84] From the perspective of mass inputs, based on currently available data, AMDE Hg entering the upper Arctic Ocean and Hudson Bay (predominantly during spring melt events) is believed to contribute a relatively small amount to what are already large reservoirs of dissolved THg. [36,253] According to a modified Global-Regional Atmospheric Heavy Metals Model (GRAHM), a net amount of 45 t year À1 THg (46 % of total annual atmospheric inputs) enters the Arctic Ocean during spring when AMDEs occur, compared with total inputs of 206 t year À1 .…”

Culturable bacteria community development in postglacial soils of Ecology Glacier, King George Island, Antarctica

“…Brevundimonas, although detected in low numbers at the glacier's edge, developed large populations later in the succession process. Members of this genus have been isolated from various polar habitats, for example, glacial snow in summer (Amato et al 2006), Antarctic soil and lakes, Arctic deep ice core and snow cover, subglacial outflow waters (Cheng and Foght 2007), and also from the Antarctic aerosol over King George Island (Miteva et al 2004;Amato et al 2006;González-Toril et al 2009). Polaromonas sp.…”