Project Summary (2000-2005)

The overall objective of this project is to evaluate in situ gene delivery as a mechanism to enhance remediation of co-contaminated soils. In this study the investigators are evaluating the influence of gene transfer to indigenous soil bacteria in two ways. First, through the addition of bacterial cells which will allow for gene transfer through conjugation. Second, "naked" DNA will be added which will allow for gene transfer through transformation. These approaches will allow for the influence of both culturable transconjugants and transformants on metal bioavailability and organic degradation to be evaluated. In addition, the analysis of community DNA will allow for the influence of total transconjugants and transformants (including nonculturable ones) on metal bioavailability and organic degradation to be evaluated. These studies are particularly relevant to the goals of the Superfund program, since it will allow remediation of sites contaminated with mixed wastes. The studies are also important because the technologies developed allow for in situ treatment of contaminated sites - a strategy that is much more economically feasible than ex situ treatment.