Bacterial characterization of the snow cover at Spitzberg, Svalbard

TLDR

The study aimed to characterize the bacterial community in the snow pack around Ny‑Ålesund, Spitzberg, Svalbard, during spring 2004. Bacterial abundance was quantified by DAPI staining, isolates were identified via 16S rRNA sequencing and deposited in GenBank, and their metabolic potential was assessed using 1H NMR to detect degradation of propionate, acetate, and formate. Bacterial concentrations ranged from 6 × 10⁴ cells mL⁻¹ at the sea shore to 2 × 10⁴ cells mL⁻¹ in glacier snow, peaking at 2 × 10⁵ cells mL⁻¹ in the 2003 summer layer, and the community comprised Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Firmicutes, and Actinobacteria, many closely related to cold‑adapted taxa and capable of degrading organic compounds during snow melt.

Abstract

A sampling campaign was organized during spring 2004 in Spitzberg, Svalbard, in the area around the scientific base of Ny-Ålesund, 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 × 104 cells mL−1, without any significant variation according to depth. In the accumulation snow layer of the glacier, concentrations were about 2 × 104 cells mL−1, except in the 2003 summer layer, where it reached 2 × 105 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.