Why Sequence Contaminated Groundwater?

Because the majority of microorganisms in nature have never been cultured, little is known about their genetic properties, biochemical functions, and metabolic characteristics. Although the sequence of the microbial community "genome" can now be determined with high-throughput sequencing technology, the complexity and magnitude of most microbial communities make meaningful data acquisition and interpretation difficult. Thus, the sequence determination of a groundwater microbial community with manageable diversity and complexity (~20 phylotypes) is a timely challenge. The samples for this project come from the Natural and Accelerated Bioremediation Research (NABIR) Field Research Center (FRC), Well FW-010. The overall objective is to provide a fundamental and comprehensive understanding of microbial community diversity at the NABIR-FRC in response to mixed waste. Based on the sequence information, whole-community microarrays will be constructed and used to address ecological questions related to bioremediation by using the samples from three funded, large-scale NABIR field research projects as well as many NABIR-funded individual projects.

Novel insights into how the microbial community adapts to extremely toxic mixed-waste environments will be obtained from sequence analysis. With its low complexity, this system will be ideal for testing the power of the shotgun sequencing approach for studying microbial community structure. Most of the bacteria identified thus far are proteobacteria. Since whole-genome sequences of many proteobacteria are available, comprehensive comparative sequence analysis can be achieved to understand the genetic basis of cultivability and survival strategies at such a highly contaminated environment. This work will also be important to obtain insights about novel uncultivated bacteria. With the support of the NABIR program, a large-scale field biostimulation activity is being carried out in the wells very close to FW-010. The sequence information could be well integrated with the studies of biogeochemistry, hydrology, microbiology, and engineering to understand the impacts of contaminants and remediation treatments on microbial community dynamics.

The whole-community sequence information will provide baseline information for understanding how contaminants affect microbial communities. This project will also help scientists design strategies for remediating mixed contaminants. In addition, it will provide an unprecedented opportunity to test ecological and evolutionary theories about the relationship between phylogenetic diversity and the functional properties of ecosystems. These issues are central to current concerns about biodiversity and are also directly relevant to understanding and managing microbial communities for bioremediation and other purposes.

CSP project participants: Jizhong Zhou (proposer) and Matthew W. Fields (Miami Univ.).