Our current understanding of Antarctic soils is derived from direct culture on selective
media, biodiversity studies based on clone library construction and analysis, quantitative
PCR amplification of specific gene sequences and the application of generic microarrays
for microbial community analysis. Here, we investigated the biodiversity and functional
potential of a soil community at Mars Oasis on Alexander Island in the southern Maritime
Antarctic, by applying 454 pyrosequencing technology to a metagenomic library
constructed from soil genomic DNA.The results suggest that the commonly cited range of
phylotypes used in clone library construction and analysis of 78–730 OTUs (de-replicated
to 30–140) provides low coverage of the major groups present (∼5%). The vast majority
of functional genes (>77%) were for structure, carbohydrate metabolism, and DNA/RNA
processing and modification. This study suggests that prokaryotic diversity in Antarctic
terrestrial environments appears to be limited at the generic level, with Proteobacteria,
Actinobacteria being common. Cyanobacteria were surprisingly under-represented at 3.4%
of sequences, although ∼1% of the genes identified were involved in CO2 fixation. At the
sequence level there appeared to be much greater heterogeneity, and this might be due to
high divergence within the relatively restricted lineages which have successfully colonized
Antarctic terrestrial environments.
CORE (COnnecting REpositories)
CORE (COnnecting REpositories)