N-183. Characterization of an Antarctic Soil Community from the Transantarctic Mountain Range

R. S. Hutchison, Z. Ashfaq, R. Strassle, N. Cornet, T. Harmer-Luke;
Stockton Coll., Pomona, NJ.

Background: Cyanobacteria, bacteria, algae, and fungi often form a living crust, called a macrobiotic crust, on soils in desert environments. A reddish, brown crust was collected from Antarctica along the shore of a small, frozen lake at the eastern side of the Beardmore Glacier, making this one of the southern-most collections of a soil crust. The purpose of our research was the isolation and purification of DNA from the crust samples, and the identification of the organisms present by sequencing the 16S and 18S ribosomal DNA, as well as the gene for the carbon fixation enzyme RubisCO. Methods: Isolation of crust DNA was achieved using standard DNA isolation kits, which yielded DNA of sufficient purity and quantity to amplify using the polymerase chain reaction (PCR). The products of PCR were analyzed with denaturing gradient gel electrophoresis (DGGE) gels. Results: The most abundant cyanobacterium strain present was Fr121 (identified using the 16S ribosomal sequence), an organism previously identified from an algal mat from Lake Fryxell, Antarctica. Algae and fungi have been cultured under continuous illumination at 6oC. A unique soil tardigrade sequence was also identified using 18S ribosomal analysis. The 16S and 18S ribosomal sequences have been used to construct a phylogenetic tree of the photosynthetic organisms present. We are currently in the process of identifying other organisms present in the crust, and are culturing these organisms at Stockton College. Conclusions: The prominent organisms present in this unique soil crust consortium have been identified. Identifying the organisms now present in this consortium is important given the potential for temperature changes in the Polar regions due to climate change.