Project Summary (2000-2006)

The broad objective of this research is to develop cost-effective technology for enhancing the rates of trichloroethene (TCE) biodegradation through bioremediation. Specifically, investigators are focusing on selecting and optimizing electron donors for the purpose of enhancing the rates of anaerobic TCE degradation. Gene clones are being used to probe for the presence and expression of TCE reductase in samples obtained for both laboratory and field studies. Further, methods are being developed to overcome the limitations of background TCE at field sites. Fluorinated hydrocarbons are being investigated as surrogates for TCE where existing background TCE concentrations limit the ability to track any injected TCE. Although field tests can be used to measure the individual microbial respiratory processes expressed by limited portions of the subsurface microflora, researchers are also developing approaches to measure the enzyme activities exhibited by subsurface microorganisms, irrespective of differences in their major metabolic or respiratory activities. This ability to estimate the size of the microbial population is providing important insights into the nature of the indigenous microbial community. Additionally, researchers are implementing these technologies for the purpose of determining the spatial and temporal variability of rates of anaerobic TCE degradation at TCE-contaminated field sites. Results from these field studies will be used to improve risk assessment capabilities.