Life on the frozen continent: diversity of RuBisCO, nifH and pufLM genes in soils around the Princess Elisabeth Station, Sør Rondane Mountains, Antarctica

In Antarctica, photosynthesis by Cyanobacteria is generally thought to be the main primary source of organic carbon for complex microbial communities. Many cyanobacterial species are also able to fix nitrogen. Therefore, they can survive and prosper in almost every habitat, including Antarctica, Earth’s most extreme continent. However, several studies of Antarctic microbial communities have shown that Cyanobacteria are not always highly abundant. We explored the hypothesis that other bacteria must take over their role and produce organic matter as well as fix nitrogen, in order to sustain the microbial community. Light is an abundant energy source during the Antarctic summer and some bacteria can use rhodopsin-type pigments to exploit this, whereas aerobic anoxygenic photosynthetic bacteria can use bacteriochlorophyll for photosynthesis. The presence and diversity of non-cyanobacterial prokaryotes that possess one or several of these properties was studied in terrestrial samples gathered in the proximity of the Belgian Princess Elisabeth Station (Sør Rondane Mountains, Queen Maud Land, East-Antarctica) by the construction of PCR clone libraries and Illumina MiSeq sequencing of RuBisCO, nifH and pufLM genes. Preliminary results indicate an extensive diversity of the genes coding for these processes in terrestrial Antarctica