T2 AM 'Omic' Technologies: Current and Future Application to Environmental Toxicology (Part 1)
Tuesday, 15 November 2005: 8:00 AM - 11:40 AM in Ballroom 2

(DEV-1117-208677) Can microbial community analyses effectively contribute to ecological assessments?

Devereux, R.¹, Fisher, W.¹, ¹ US EPA NHEERL Gulf Ecology Divsion, Gulf Breeze, FL, USA

ABSTRACT- Microbial communities respond rapidly to environmental changes including stressors such as hydrocarbon pollutants, heavy metals and nutrient enrichment. They therefore have potential value in ecological assessments. Bacteria are widely used as indicators of fecal pollution and chlorophyll concentrations may be used to assess water quality relative to nutrient loadings. Can microorganisms tell us more about environmental condition? Over the last 20 years, microbial community ecology has been strengthened as a discipline by technological progress that provides community information in greater detail than was previously possible using traditional cultivation-dependent approaches. These advances, based on retrieval of genetic information (i.e., DNA sequences) directly from microorganisms in environmental samples, allow determinations of microbial community composition, diversity, and genetic potential independent of any need to culture them in the laboratory. The first complete genome sequences obtained were from bacteria and subsequent advances have been rapid. It can be expected that genomic-enabled technology will ultimately translate into efficient and useful methods for microbial ecology and potentially ecological assessments. Microarray technology, for example, is an attractive tool for ecological assessments because it can be used to characterize bacterial communities in terms of taxonomic composition, heavy metal resistance, hydrocarbon degradation, or nutrient cycling. However, the utility of microbial community measurements for ecological assessment remains an open question. Useful ecological indicators require that measurements are relevant to an assessment question, feasible to implement, transportable among different environments, and sufficiently straightforward that interpretations can be embraced by resource managers, lawmakers and the public. Moreover, development of a useful tool requires validation and technical transfer to State and Federal regulatory departments. Development of ecological indicators from measurements of microbial communities requires a strong understanding of the assessment needs; application to an assessment will require a comprehensive strategy to address the needs of the stakeholders.

Key words: microbial communities, ecological assessments, indicator development, genomics indicators