Microbial communities associated with Antarctic snow pack and their biogeochemical implications

Abstract

Snow ecosystems represent a large part of the Earth's biosphere and harbour diverse microbial communities. Despite our increased knowledge of snow microbial communities, the question remains as to their functional potential, particularly with respect to their role in adapting to and modifying the specific snow environment. In this work, we investigated the diversity and functional capabilities of microorganisms from 3 regions of East Antarctica, with respect to compounds present in snow and tested whether their functional signature reflected the snow environment. A diverse assemblage of bacteria (Proteobacteria, Actinobacteria, Firmicutes, Bacteroidetes, Deinococcus-Thermus, Planctomycetes, Verrucomicrobia), archaea (Euryarchaeota), and eukarya (Basidiomycota, Ascomycota, Cryptomycota and Rhizaria) were detected through culture-dependent and -independent methods. Although microbial communities observed in the three snow samples were distinctly different, all isolates tested produced one or more of the following enzymes: lipase, protease, amylase, β-galactosidase, cellulase, and/or lignin modifying enzyme. This indicates that the snow pack microbes have the capacity to degrade organic compounds found in Antarctic snow (proteins, lipids, carbohydrates, lignin), thus highlighting their potential to be involved in snow chemistry.

Characteristics and sources of dissolved organic matter in a glacier in the northern Tibetan Plateau: differences between different snow categories

“…This phenomenon is similar to those found in surface snow samples from the East Antarctic ice sheet and the cryoconites in LHG (Antony and others, 2014; Feng and others, 2016). Previous studies have suggested that the predominant lipid- and aliphatic/protein-like components were produced by a diverse assemblage of bacteria, archaea and eukarya which could degrade and produce DOM in the Antarctic snowpack (Antony and others, 2016, 2017). In addition to the predominantly autochthonous microbial material, terrestrial components were also found in each type of sample, as shown by the presence of tannin and lignin/CRAM molecules (12.4–20.6%) in the van Krevelen diagrams (Fig.…”

Microbial Community Analysis of Colored Snow from an Alpine Snowfield in Northern Japan Reveals the Prevalence of Betaproteobacteria with Snow Algae

“…The profile of non-algal eukaryotic phyla detected most abundantly belong to members of the phyla Basidiomycota , Cercozoa , and Chytridiomycota . Members of the phyla Basidiomycota and Chytridiomycota have also been reported to be prominent in high elevation soils, Antarctic snow, and arctic sea ice and sediment ( Freeman et al, 2009 ; Antony et al, 2016 ; Hassett and Gradinger, 2016 ). Cercozoa species were also detected in arctic freshwater lakes ( Charvet et al, 2014 ).…”

Climate driven carbon and microbial signatures through the last ice age

“…1c-d and Fig. S-2) could favour microbial communities based on their metabolic capabilities; a concept of community evolution supported by recent findings on microorganisms in Antarctic snow (Antony et al, 2016). Although metabolic functions can be inferred from 16S RNA gene datasets (Bowman and Ducklow, 2015), obvious limitations exist compared to more detailed 'omics' studies; thus, our interpretations should be viewed as highly conservative, first approximations.…”