Metaproteomic Comparison of Cryoconite Communities from Caucasian and Novaya Zemlya Glaciers

Anthropogenic pollution strongly affects glacial microbiological communities and promotes glacial melting. In the early stages of glacial melting formation of small cylindrical holes (cryoconite) occurs. While the microbiome of cryoconite is well described, the effect of anthropogenic pollution on cryoconite microbiological communities still has not been fully understood. Thus, we performed an unbiased functional comparison of the cryoconite communities from the highly polluted Caucasian glaciers and from less polluted glaciers in Novaya Zemlya. For this purpose, we used the shotgun metaproteomics approach which has not been used for cryoconite microbiome analysis previously. We identified 475 protein groups, a third of which were found in both glaciers. Cryoconites in both glaciers have similar microbiological communities with Cyanobacteria as dominant phyla. Nevertheless, we found a slight shift from the dominance of phototrophic Cyanobacteria in Novaya Zemlya to heterotrophic bacteria in the Caucasus. We assume that it might be caused by anthropogenic pollution, but other factors such as differences in seasonal dynamics of microbiological communities should be tested in the future.