Superfund Research Program
Microbial Detoxication/Degradation of Hazardous Wastes
Center Director: Kathleen Dixon (University of Arizona)
Grant Number: P42ES004908
Funding Period: 1995-1999 and 2001-2006
This program focuses on microbial detoxification and degradation of hazardous wastes. The main objective of the program is to reduce risk to human health by improving methods for detecting hazardous substances and by developing advanced microbial systems to degrade recalcitrant pollutants. Persistent environmental toxicants under study include polyaromatic hydrocarbons, azodyes and metals. The program consists of seven research projects which include interdisciplinary basic research, training, and an industrial outreach plan.
Throughout the program the majority of projects emphasize various aspects of biodegradation. One project is examining the genes and pathways of microbial P450 monooxygenases and azoreductases. With increased understanding of these enzyme systems it will be possible to develop improved biotreatment technologies. Another project is concerned with identifying the biological and physio-chemical parameters important in fate and degradation of azodyes. In a related study, researchers are trying to isolate organisms capable of degrading 4 and 5 ring aromatic hydrocarbons and N-heterocyclic compounds as they exist in metal-contaminated soils. There is also a project which is examining rhizosphere biodegradation of organic pollutants.
Developing methods to be utilized by industry is an important part of the design of this program. In a project which strives for eventual application to full-scale treatment systems, researchers are examining biofilms in order to understand the transport of toxic organics and organometallics, and also to characterize microbial populations which are involved in biodegradation. In a comparable endeavor, analytical methods are being developed for ultra-trace measurement using chromatographic and plasma mass spectrometry techniques which can be applied to complex samples.
To further the understanding of risk to human health, the program includes a biomedical research project which focuses on chromium mutagenesis. The project is examining mechanisms of genetic damage by assessing mutational spectra using genetic targets in shuttle vectors. The purpose of this research is to understand the mechanisms by which chromium causes mutations in mammalian cells and also to provide a link between the mutagenic and carcinogenic activities of chromium. Such research can be applied in understanding other mutagenic and carcinogenic substances.
The overall program is supported by an administrative core and training core, and a technology resource core. The training core has both successful undergraduate and graduate training programs which is also extended downward through an outreach program to high, middle, and K-4 school children. In an effort to idenify minority students for post baccalaureate education, this Program provides summer research scholarships for eligible students from Central State University. The technology resource core provides for methods development for new research areas and in interactions for technology transfer to industry.