Snow Surface Microbiome on the High Antarctic Plateau (DOME C)

Abstract

The cryosphere is an integral part of the global climate system and one of the major habitable ecosystems of Earth's biosphere. These permanently frozen environments harbor diverse, viable and metabolically active microbial populations that represent almost all the major phylogenetic groups. In this study, we investigated the microbial diversity in the surface snow surrounding the Concordia Research Station on the High Antarctic Plateau through a polyphasic approach, including direct prokaryotic quantification by flow cytometry and catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH), and phylogenetic identification by 16S RNA gene clone library sequencing and 454 16S amplicon pyrosequencing. Although the microbial abundance was low (<103 cells/ml of snowmelt), concordant results were obtained with the different techniques. The microbial community was mainly composed of members of the Alpha-proteobacteria class (e.g. Kiloniellaceae and Rhodobacteraceae), which is one of the most well-represented bacterial groups in marine habitats, Bacteroidetes (e.g. Cryomorphaceae and Flavobacteriaceae) and Cyanobacteria. Based on our results, polar microorganisms could not only be considered as deposited airborne particles, but as an active component of the snowpack ecology of the High Antarctic Plateau.

The environmental and host‐associated bacterial microbiota of Arctic seawater‐farmed Atlantic salmon with ulcerative disorders

“…The recovery of eukaryotic sequences from chloroplast sequence contamination in 16S rRNA gene analysis has been reported in a number of datasets (Michaud et al . ; Zarkasi et al . ).…”

“…Amplicons affiliated to the chloroplast of unicellular eukaryotes were found in high abundance from seawater samples. The recovery of eukaryotic sequences from chloroplast sequence contamination in 16S rRNA gene analysis has been reported in a number of datasets (Michaud et al 2014;Zarkasi et al 2014). Haptophyceae reads are dominated by Phaeocystis globosa and account for half of the classified reads from April sea water.…”

Microbial metabolism directly affects trace gases in (sub) polar snowpacks

“…Furthermore, the presence of microbes in remote, low-nutrient, low-water, very cold environments such as polar glacial surfaces and their snowpacks is well established [28,29]. However, the level to which microorganisms are metabolically active in the snowpack as its water content becomes scarce and temperatures drop remains contentious, as the only evidence to date remains correlative or circumstantial [19,22,30]. Research has shown that microorganisms can be incredibly persistent, even deep within high plateau polar ice, remaining culturable even after hundreds of thousands of years (see [22] references therein).…”

Microbial Community Structure and Metabolic Networks in Polar Glaciers

“…Being in higher latitudes allows the existence of very low temperatures and high rates of solar radiation in summer. Some published reports on glacial and subglacial microbiology refer to very extreme latitudes that reach −75°S in the high Antarctic Plateau [13], −77°S in Lake Vostok [14], and −84°S in the West Antarctic ice sheet [15] (Figure 1).…”