Antarctic cyanobacterial diversity: how important are the geographical and ecological factors?

Conference (2012, October 31)

On the Antarctic continent, cyanobacteria produce conspicuous benthic microbial mats in lakes, from the coastal regions to the mountains (till 84°S). However, little is known about theirl biodiversity in ... [more ▼]

On the Antarctic continent, cyanobacteria produce conspicuous benthic microbial mats in lakes, from the coastal regions to the mountains (till 84°S). However, little is known about theirl biodiversity in comparison with other regions of the world. The BelSPO project AMBIO aimed to test whether (i) microbial communities are structured by the same factors as those shaping communities of macroorganisms, and (ii) endemism among cyanobacteria does exist. We have analyzed the cyanobacterial biodiversity in a variety of aquatic habitats from the three main biogeographical regions (Continental, Maritime Antarctica and the Sub-Antarctic) and determined the ‘baseline’ data needed to understand the contribution of various processes that are responsible for the distribution patterns. [less ▲]

Cyanobacterial 
molecular 
diversity 
and distribution 
in 
microbial 
mats from 
antarctic 
lakes

Poster (2009, December 11)

The coastal deglaciated areas of Antarctica hold lakes and other water bodies with a wide spectrum of limnological conditions. Aquatic habitats offer milder conditions to the microorganisms, which are the ... [more ▼]

The coastal deglaciated areas of Antarctica hold lakes and other water bodies with a wide spectrum of limnological conditions. Aquatic habitats offer milder conditions to the microorganisms, which are the only permanent inhabitants of this glacial desert. Among them, cyanobacteria are the first photosynthetic colonisers, sometimes forming thick, cohesive and pigmented benthic mats. In the frame of the BELSPO AMBIO project (Antarctic Microbial BIOdiversity, influence of geographical and ecological factors, www.ambio.ulg.ac.be), we have obtained benthic mat samples coming from lakes from various coastal regions of the continent (MERLIN 2007 and BELARE 2007 field campaigns and by collaborations). We have investigated cyanobacterial molecular diversity via Polymerase Chain Reaction and Denaturating Gradient Gel Electrophoresis (PCR-DGGE) on a set of 80 samples. We couple the numerical analysis of the obtained band patterns with the phylogenetic analysis of the sequences, and by using multivariate analysis, we will assess the role of the ecological and geographical factors shaping the distribution and the diversity of cyanobacteria. Preliminary results of the analysis of 13 samples seem to indicate that lakes separated by a small distance have different cyanobacterial communities, highlighting the importance of ecological factors. Fifty per cent of the obtained Operational Taxonomic Units (OTUs) are potentially endemic to Antarctica while others seem to have a global distribution. The completed study will give us a wide scale view on the distribution and the diversity of cyanobacteria in two biogeographical zones: Continental Antarctica and Maritime Antarctica. Finally, our studies will supply new data and arguments for the ongoing “everything is everywhere, but the environment selects” debate concerning microbial biogeography. [less ▲]

Molecular Diversity of Antarctic Cyanobacteria

Scientific conference (2008, December 12)