Chlorinated Hydrocarbon Degradation in Plants: Mechanisms and Enhancement of Phytoremediation of Groundwater Contamination

University Of Washington, Seattle WA

Investigators

Abstract

9911676 Strand The objectives of this research are to improve the efficiency of phytoremediation of haolgenated hydrocarbons (HHCs) by studying the fundamental mechanism of HHC degradation in plants and, by genetic engineering, to provide improved strains of trees capable of more rapid ant thorough uptake of HHCs. Previous work has shown that trees and other plants are capable of taking up and oxidizing HHCs such as trichloroethylene, perchloroethylene and carbon tetrachloride to chloride ion and carbon dioxide. Pilot scale trials have shown that full-size poplar trees growing in the field can take up large amounts of HHCs while producing very little air emissions. The goal of this research is to gain a fundamental understanding of the transformation mechanisms in plants and, by using this knowledge, to increase HHC degradation in plants by genetic engineering. Molecular and biochemical assays suggest that a plant enzyme similar to the mammalian cytochrome P450 2E1 is involved in HHC degradation. This research will seek to determine the mechanism of HHC oxidation in plants, to isolate the genes responsible for that oxidation, to further analyze the improved capabilities of transgenic plants and to transform poplar and other tree species to optimize their HHC oxidative activities. If successful, this research could lead to more cost-effective means of treating soils contaminated with HHCs. ***