The overall objective of this project is to evaluate in situ gene delivery as a mechanism to enhance remediation of co-contaminated soils. Specific aims are: 1) To evaluate new conjunctive systems as a mechanism for gene delivery into the soil microbial gene pool through the introduction of whole cells, ii) To evaluate enhanced transformation as a mechanism for gene delivery into the soil microbial gene pool through the introduction of 'naked' nucleic acid, iii) To evaluate the use of biosurfactants to enhance transport of introduced genes through co-contaminated soils, and iv) To evaluate the fate of 'naked' DNA introduced into soils. In this study we will evaluate 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 degradation to be evaluated. In addition, the analysis of community DNA will allow for the influence of total transconjugants and transformants (including non-culturable 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. These sites are difficult problems, and a potential source of pollutants that adversely affect human health and welfare. The studies are also important since the technologies developed allow for in situ treatment of contaminated sites-a strategy that is much more economically feasible than ex situ treatment.