CAREER: Ecology of Chlororespiring Bacterial Populations and Biochemical Studies of the Dehalogenating Enzyme Systems

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

Most living beings we observe in nature breathe oxygen, a prerequisite for the existence of aerobic organisms, including humans. In many lake and river sediments or waterlogged soils oxygen is not available, yet many bacteria thrive in such oxygen-depleted (anaerobic) environments. Instead of oxygen, anaerobic bacteria use other compounds to drive respiration, compounds such as nitrate, sulfate, or, as recent discoveries have demonstrated, chlorinated chemicals. Respiration using chlorinated compounds destroys those chlorinated chemicals, and hence, diminishes toxicity to humans. This project will elucidate distribution, abundance, diversity, physiology, and ecological function of bacterial populations that respire with chlorinated compounds. The PI will characterize the enzymes involved, explore the diversity of dechlorinating enzyme systems in these bacteria, and explore the evolution of these systems. Samples from a variety of geographically distinct locations (including Antarctica, Siberian permafrost, the deep subsurface, hydrothermal vents, and hot springs) will be examined, and bacterial populations of interest will be studied in detail. State-of-the-art nucleic acid-based tools will be used and improved to detect, monitor, and quantify these organisms. Because man-made chlorinated compounds (e.g. pesticides, solvents, etc.) are major environmental pollutants, this project, aimed at understanding the basic biology and ecology of chlororespiring bacteria, can provide a basis for exploring how these specialized organisms can be exploited to assist in clean-up efforts at contaminated sites. This is a CAREER award, integrating research and educational activities. Undergraduate and graduate students will be involved in this research project. To improve minority participation and faculty interaction, a Visiting Student Researcher Development (VSRD) program with the University of Puerto Rico at Mayaguez will be initiated. In addition, high school teachers (and their students) will be given an opportunity to experience new technologies by participating in a summer program of scientific inquiry.