UNS: Organohalide Respiration: Improving our Understanding for Predictable Biostimulation and Bioaugmentation

1510131

Novak, Paige J.

Title: Organohalide Respiration: Improving our Understanding for Predictable Biostimulation and Bioaugmentation

Over the next 30 years, the EPA has estimated that it will cost $250 billion to remediate approximately 350,000 contaminated sites in the US, many of which are contaminated with chlorinated pollutants. In contaminated environments bacteria of a specific kind have been identified that treat chlorinated pollutants, producing less- or non-toxic compounds as products. This proposed project will examine the various aspects of these bacteria to effectively treat these compounds in the ground, therefore lowering the cost of treatment.

In this project, laboratory-based experiments will be performed to determine, (1) how the organohalide respiring community and genes that code for the dechlorinating activity (rdh genes) change when enriched with chlorinated natural organic matter, (2) how the concentration of chloride, chlorinated natural organic matter, or chlorinated pollutants affect the numbers of organohalide respiring organisms present and the degradation rate of chlorinated natural organic matter, and finally, (3) the effectiveness of chlorinated natural organic matter as a primer for the degradation of chlorinated pollutants. This research will further understanding of organohalide respiration by investigating the rdh genes present during the dechlorination of chlorinated natural organic matter. In addition, by determining whether or not chlorinated natural organic matter can be co-degraded with a chlorinated pollutant (a polychlorinated biphenyl congener) and which rdh genes are present when this occurs, the relationship between the respiration of natural compounds versus pollutants will be established. This research has critical implications for the remediation field, ecology, and geochemical cycling by (1)providing the discovery of a pathway for the cycling of natural organic chlorine, (2) opening an avenue for further research on the evolution and regulation of rdhs, (3) pointing to a source of organisms for bioaugmentation, and a source of natural compounds for biostimulation, and (4) facilitating the development of a tool to determine the organohalide respiration potential of a soil via the mapping of the rdh genes present. The students involved in this project will be trained in a variety of laboratory methods, and the experimental and critical thinking skills developed during this study will complement their current curriculum and future careers as engineers/scientists.