Diversity and metabolic abilities of Antarctic bacteria - DGGE fingerprinting of bacteria

Bacterial community structures in soils collected from eight sites around Casey Station, Antarctica, were investigated using denaturing gradient gel electrophoresis (DGGE) of amplified 16S rRNA gene fragments. Higher bacterial diversity was found in soils from protected or relatively low human-impacted sites in comparison to highly impacted sites. However, the highest diversity was detected in samples from Wilkes Tip, a former waste disposal site that has been undisturbed for the last 50 years. Comparison of community structure based on non-metric multidimensional scaling plots revealed that all sites, except the hydrocarbon-contaminated (oil spill) site, were clustered with a 45% similarity. A total of 23 partial 16S rRNA gene sequences were obtained from the excised DGGE bands, with the majority of the sequences closely related to those of the Cytophaga-Flexibacter-Bacteroides group. No significant correlation was established between environmental variables, including soil pH, electrical conductivity, carbon, nitrogen, water content and heavy metals, with bacterial diversity across the eight study sites.

Irene K. P. Tan - Project leader
C. W. Chong - sample collection, molecular and statistical analyses
G. Y. Annie Tan - provided some advice in molecular analysis
Richard C. S. Wong - provided advice in chemical analyses
Martin J. Riddle - assisted in manuscript writing and provided advice in metal analyses

Locations used in this experiment were:

- Casey Red Shed
- Oil Spill site
- Thala Valley
- Wilkes Tip
- Browning Peninsula
- Mitchell Peninsula
- ASPA 135
- ASPA 136