In the present project, we aimed to extend the baseline information of microbial diversity through an integrated and standardized analysis of the microbial diversity of aquatic habitats in terrestrial Antarctic environments. We aimed to use a polyphasic approach combining morphologic characterization by microscopy with molecular techniques in order to reveal the diversity of bacteria, cyanobacteria and protists (with special emphasis on green algae and diatoms), which have been identified as interesting focal taxa during our earlier studies. To work in parallel on environmental samples and isolated strains in culture allows us to obtain a more complete image of the diversity.