(116s) Exploring the Phylogenetic Diversity of the Homestake Gold Mine, Lead, SD

16s rDNA sequence studies are efficient and economical ways to determine population compositions, especially in extreme environments where the isolation and growth of microorganisms is difficult or impossible. In previous work, samples from water and rock particulates (?soil?) were collected from the Homestake Gold Mine, Lead, SD, which is currently being converted to a Deep Underground Science and Engineering Laboratory supported by the National Science Foundation. DNA extracted from these samples was then used to construct clone libraries for both Archaea and Bacteria. The focus of this study was analysis of the sequenced libraries. Using the Bellerophon server and VecScreen system, sequences were processed for chimeric artifacts and vector contamination, respectively. Then, sequence sets were aligned using the ClustalW algorithm and phylograms were constructed using MEGA 4.0, for which neighbor-joining trees with the Jukes-Cantor method of inference were used. The results show that the majority of both the water and soil bacteria sets are Proteobacteria, with the β-proteobacteria class most prevalent in water, and the γ-proteobacteria class predominant in soil. In addition, a number of sequences in the soil set closely relate to Lysobacter, a genus known for producing novel antibiotics, while other sequences group closely to organisms which produce heat stable proteases (e.g. Chryseobacterium) or cellulolytic enzymes (e.g. Dyella). Overall, the bacterial populations show a high degree of uniqueness, although their diversity is low. The Archaea sequence sets show distinct grouping based on the sample origin. This, along with a dearth of reference sequence similarity, suggests the possibility of divergent Archaeal populations with novel organisms.

This study was supported in part by the SD NASA EPSCoR Program under NASA award No. NCC5-588 and the SD 2010 Center for Bioprocessing Research and Development.