Diversity of the cyanobacterial communities from the Sør Rondane Mountains (Eastern Antarctica).
MJ. Mano1, Z. Namsaraev1,2, R. Fernandez-Carazo1, D. Ertz3 and A. Wilmotte1.
1Centre for Protein Engineering, Liège, Belgium; 2Winogradsky Institute for
Microbiology RAS, Moscow, Russia; 3National Botanical Garden of Belgium, Meise,
Belgium.
The new Belgian “Princess Elisabeth” research station was built in 2009 and is located 200 km inland in the Western part of the Sør Rondane Mountains (Eastern Antarctica). The BELSPO projects ANTAR-IMPACT and BELDIVA aimed to evaluate the diversity and the distribution patterns of the microorganisms from different types of habitats in a radius of 50 km around the Belgian station. These data will serve to follow future anthropogenic and climatic impacts on these communities. Here, we focus on the diversity of cyanobacteria.
During the campaigns of the austral summers 2007, 2009 and 2011, 157 terrestrial samples were taken from 9 different sites, including cryoconites, nunataks and a dry valley. To estimate the cyanobacterial diversity from each site, a polyphasic approach was used, based on microscopic observations and molecular studies by DGGE (for 60 selected samples).
The morphological analysis showed the presence of at least 15 morphotypes. The number of morphotypes ranged from 0 to 10 per sample.
With the DGGE, we found at least 33 cyanobacterial OTUs (more than 97.5% 16S rRNA sequence similarity) and 3 groups of sequences affiliated to green algal chloroplasts. Fourteen OTUs were potentially endemic to Antarctica, including 10 OTUs that were only found in the Sør Rondane Mountains and 19 OTUs that had a cosmopolitan distribution. The number of OTUs varied between 0 to 5 per sample.
The cyanobacterial sequences belonging to the OTUs related to
Chrococcidiopsis sp., Cyanothece aeruginosa, Leptolyngbya sp., Phormidium autumnale and Phormidium priestleyi were the most widely distributed in this
Antarctic region.
The area of the Belgian station harbors a quite large cyanobacterial diversity despite permanently negative air temperatures. This high diversity may be explained by the presence of terrestrial microhabitats with improved environmental conditions. The local warming of rocks and the presence of meltwater allow the growth of cyanobacteria during the austral spring and summer. Precautions should be taken to minimize future anthropogenic impacts on these diverse communities due to the research station activity.
