16S rRNA surveys of Antarctica's McMurdo Dry Valleys reveal diverse and novel microbes: can we culture them?

For many decades the soils of the McMurdo Dry Valleys, Antarctica were thought to be essentially sterile.  We now know that this is an ecosystem that is dominated by microorganisms, however, early cultivation efforts largely failed to detect the biodiversity of the region’s poorly weathered, low organic carbon soils.  Initial surveys of microbial diversity using 16S rRNA gene sequencing has revealed a surprising bacterial richness, including representatives from at least ten different phyla, including a high proportion of unique and rare sequences.  Based on metagenomics, or random sequencing of environmental DNA from the Taylor and Wright Valleys, we have identified the dominant organisms that represent novel bacterial species.  Our metagenomic data provide a glimpse of their metabolic potential, which combined with information from their closest cultivated relatives, provides hints for developing a cultivation strategy for these novel species.  We are using two media TSA and R2A, (full and half strength) to enrich and isolate bacteria from these soils by performing serial dilution of the soils and incubating at 4 degrees C in both broth and agar media. Growth conditions such as temperature, pH, and aerobic or anaerobic conditions will be adjusted for optimal growth based on the results of preliminary findings. Isolated cultures will be characterized biochemically and phylogentically to provide a better understanding of the dominant members of McMurdo Dry Valley soils, which given their novel and wide microbial diversity, represent an important genomic reservoir.