Cryoconite holes on frozen lakes as source of interesting extremophilic and extremotolerant organisms

The key thought of this short communication is biodiversity evaluation of the photo-autotrophic inhabitants of lake cryoconite holes and point out their potencial as extremo-tolerant or even extremophilic organisms that deserve attention. Cyanobacterial diversity of these environments was investigated in cryoconites holes of 2 permanently and 1 sea-sonally ice-covered lakes at James Ross Island. Twelve species from different taxonomic groups, both coccal and filamentous (with and without heterocytes) cyanobacteria, were determined using a light microscope and morphological features of autorophic microorganisms. The results suggested relatively high diversity in such extreme environments and also indicated potential of lake cryoconites to serve as a reservoir of organism that can have special protection properties.