Microbial community variation in cryoconite granules on Qaanaaq Glacier, NW Greenland

Abstract

Cryoconite granules are aggregations of microorganisms with mineral particles that form on glacier surfaces. To understand the processes by which the granules develop, this study focused on the altitudinal distribution of the granules and photosynthetic microorganisms on the glacier, bacterial community variation with granules size and environmental factors affecting the growth of the granules. Size-sorted cryoconite granules collected from five different sites on Qaanaaq Glacier were analyzed. C and N contents were significantly higher in large (diameter greater than 250 μm) granules than in smaller (diameter 30-249 μm) granules. Bacterial community structures, based on 16S rRNA gene amplicon sequencing, were different between the smaller and larger granules. The filamentous cyanobacterium Phormidesmis priestleyi was the dominant bacterial species in larger granules. Multivariate analysis suggests that the abundance of mineral particles on the glacier surface is the main factor controlling growth of these cyanobacteria. These results show that the supply of mineral particles on the glacier enhances granule development, that P. priestleyi is likely the key species for primary production and the formation of the granules and that the bacterial community in the granules changes over the course of the granule development.

Snapshot of micro-animals and associated biotic and abiotic environmental variables on the edge of the south-west Greenland ice sheet

“…Uetake et al (2010Uetake et al ( , 2016 also noticed a clear domination of a filamentous chlorophyta species. It was accompanied by the desmidia of Cylindrocystis brebissonii, also identified in one of the studied locations, which may suggest that it is a species characteristic of cryoconite holes.…”

“…Among the many studies on cryoconite holes in Greenland (Cook et al 2016;Hodson et al 2010a;Stibal et al 2010) few describe cyanobacteria and algae assemblages (Uetake et al 2010(Uetake et al , 2016Kaczmarek et al 2016). The Klebsormidium genus has been often recorded in extreme Arctic habitats and has a high tolerance to gradients of light, temperature and UVR (Kitzing and Karsten 2015).…”

Ecological Modeling of the Supraglacial Ecosystem: A Process-based Perspective

“…Abundance of other, mostly heterotrophic, microbes in surface ice has been found to correlate with dust concentration (Stibal et al, 2015a). Cryoconite, usually concentrated in cryoconite holes , hosts diverse and highly active microbial communities that consist of photoautotrophic cyanobacteria and a range of heterotrophic bacteria (Cameron et al, 2012(Cameron et al, , 2016Stibal et al, 2012bStibal et al, , 2015bEdwards et al, 2014;Uetake et al, 2016). Cryoconite holes provide a stable and nutrient-rich habitat within the supraglacial ecosystem, and are considered hotspots of microbial activity on glacier surfaces Cook et al, 2016a).…”

Applicability of cryoconite consortia of microorganisms and glacier-dwelling animals in astrobiological studies

“…They are granular/spherical mineral particles connected with archaea, algae, cyanobacteria, fungi, heterotrophic bacteria and micro animals (mainly Tardigrada and Rotifera), the latter feed on these consortia (Figs 1C and 1D,Figs 2A and 2B). Forming of cryoconite granules is possible because of extra polymeric substances produced by cyanobacteria which cause the aggregation of mineral dust and other organisms (Figs 1C and 1D) (Takeuchi et al 2001;Hodson et al 2008Hodson et al , 2010Langford et al 2014;Cook et al 2015;Uetake et al 2016). The decreasing of albedo induced by cryconites influences the formation of cryoconite holes.…”

“…Cryoconite sediments on glaciers and in cryoconite holes are one of the most extremophile organisms consortia which appear on all investigated glaciers from polar to high alpine regions (e.g., Porazińska et al 2004;Hodson et al 2008;Cook et al 2015;Zawierucha et al 2016b). To date, cryophilic organisms inhabiting glaciers (cryoconites and cryoconite holes) have been studied in different aspects: from taxonomy, ecology and biogeography, to searching of biotechnological potentials and physiological strategies to survive in cryoconite holes (e.g., Hodson et al 2008;Singh et al 2014a,b;Grzesiak et al 2015;Lutz et al 2016;Uetake et al 2016;Zawierucha et al 2016a). However, they have never been used in astrobiological experiments.…”