Project Summary (1995-2000)

The goal of this project is to understand the requirements, dynamics, and limitations on the functioning of degradative microorganisms in natural ecosystems such as soil. This includes limitations on indigenous microorganisms, as well as introduced genetically-modified microorganisms, and on the growth and functioning of plants and plant/microbe systems. Most ecological studies of remedial organisms have examined single isolates of bacteria or fungi; relatively little is known about the ecology of microbial consortia or the mutualistic association of remedial microorganisms with plants. Moreover, little is known about the limitations to bioremediation in complex systems which often contain more than one toxic organic chemical or heavy metal. Specific aims of the project are to determine the environmental factors affecting the survival and activity of degradative microorganisms introduced into contaminated soil; to investigate the important metabolic, ecological, and genetic interactions which influence the degradative activity of microbial consortia; to examine the effects of soil metals; to determine the potential for transfer of metals and organics into the food chain via plant uptake; and to investigate the potential for soil remediation via plant uptake and transformation.