Dissertation Research: Investigations of a Dynamic Microbially-Mediated Iron Cycle in the Rhizosphere of Wetland Plants

George Mason University, Fairfax VA

Investigators

Abstract

00-73980 Megonigal / Weiss DDIG: Investigations of a dynamic microbially-mediated iron cycle in the rhizosphere of wetland plants Wetlands naturally filter pollutants from streams, rivers, lakes and groundwater. The investigators have found iron-oxidizing bacteria living on plant root surfaces that can use dissolved iron -a pollutant at high concentrations- as an energy source, thus removing it from water. Other forms of bacteria consume the rust coating on roots and release it back into the water. This creates a cycle of iron being trapped and released in the wetland system. The investigators will study the types of bacteria present and their role in the wetland iron cycle to determine if wetlands remove and store iron in wetland soils over long time periods. The research will also examine the effects of the iron cycle in the wetland plant rhizosphere on methanogenesis.