Comparative phylogenetic microarray analysis of microbial communities in TCE-contaminated soils.

The arrival of chemicals in a soil or groundwater ecosystem could upset the natural balance of the microbial community. Since soil microorganisms are the first to be exposed to the chemicals released into the soil environment, we evaluated the use of a phylogenetic microarray as a bio-indicator of community perturbations due to the exposure to trichloroethylene (TCE). The phylogenetic microarray, which measures the presence of different members of the soil community, was used to evaluate unpolluted soils exposed to TCE as well as to samples from historically TCE polluted sites. We were able to determine an apparent threshold at which the microbial community structure was significantly affected (about 1ppm). In addition, the members of the microbial community most affected were identified. This approach could be useful for assessing environmental impact of chemicals on the biosphere as well as important members of the microbial community involved in TCE degradation.