A Comparative Study of Endolithic Microbial Communites between Different Types of Rocks in the Norwegian High Arctic

Abstract

In extreme environments, such as the Arctic, endolithic communities are most of the extant life. The endolithic environment is thought to buffer microbial com-munities from intense solar radiation, temperature fluctuations, wind, and desiccation in environments where such environmental factors inhibit epilithic growth. Therefore, the endolithic environment is a critical habitat to explore in exobiological research. The abundance of endolithic life in the high Arctic, combined with the potential for biosignature preserva-tion, suggests that rocks associated with endolithic ecosystems may be the best hope for finding fossil evidence of past life on the Martian surface. The goal of this study is to assess the activity and community composition of the endolithic community inhabiting rocks in the Norwegian high Arctic. To achieve this goal, we combined techniques of DNA sequencing, microscopy and spectroscopy. This work provides an overview of the polar microbial communi-ty and a new recognition of how environmental stresses such as prevailing polar desert conditions may affect the biogeochemical dynamics of high Arctic endolithic microorganisms.