The ikaite columns in the Ikka Fjord, SW Greenland, constitute a cold (4 °C), alkaline (pH 10.4), and low-salinity (0.9 %) environment, and they harbor a microbial community adapted to this polyextreme environment. 16S rRNA gene sequence analyses show that the community is rich in new species and that Proteobacteria are dominating. So far, three new species have been characterized and described in detail: Rhodonellum psychrophilum, Arsukibacterium ikkense, and Alkalilactibacillus ikkensis. The bacteria produce a diversity of enzymes, including proteases, lipases, β-galactosidases, and phosphatases. These enzymes are adapted to the polyextreme environment and have application potentials in industrial and biotechnological processes. In this chapter, the research on the microbial population of the ikaite columns that has been conducted over the past decade will be reviewed.
