Bacterial and archaeal diversity in high altitude wetlands of the Chilean Altiplano

The microbial diversity of five unconnected high altitude (>= 3800 m a.s.l.) wetlands from the Chilean Altiplano was analyzed by a culture-independent approach, using 16 S rRNA gene sequences of different microbial groups. The wetlands (Chungara Lake, Parinacota wetland, Piacota Lake, Salar de Huasco and Salar de Ascotan) differed in terms of habitat type and physicochemical properties. The bacterial communities of these systems were dominated by Bacteroidetes (24-94 % of the clones) and Proteobacteria (Alpha, Beta, Gamma and Delta subgroups) with smaller contributions by the Firmicutes, Actinobacteria, Planctomycetes, Verrucomicrobia, Chloroflexi, Cyanobacteria, Acidobacteria, Deinococcus-Thermus and Candidate Division WS3. Fourteen phylotypes matching Alphaproteobacteria were part of the marine Roseobacter clade, representing new clusters of this group. Archaeal diversity was much lower than that seen for bacteria, and was dominated by Euryarchaeota; however Crenarchaeota were also present. Considering the large differences in microbial community composition between sites and samples, the presence of eleven phylotypes common to two or more habitats is highlighted. The frequent presence of new taxa in different phylogenetic groups in the altiplanic wetlands studied here revealed the unique characteristics of Bacteria and Archaea in these fragile Andean ecosystems.