Professor; Ph.D. Cornell University, 1976. Microbial ecology

Active projects examine the microbial transformations of organic and inorganic pollutants and trophic transfer of energy through microorganisms. A main line of inquiry deals with bacteria in the subsurface (groundwater) environment. Current projects include investigation of factors controlling the movement of bacteria in porous media, metabolism of contaminant hydrocarbons at the saturated/unsaturated zone interface, and the effect of that metoblism on the geochemical conditions within the aquifer. Close collaboration with physical scientists (hydrologists, geochemists) is an important part of research in microbial ecology of the surface and subsurface. An additional line of research examines microbial communities with respect to the role their structure plays in determining the fulfillment of their role in the ecosystem. Phenomena such as redundancy, congeneric homotaxis, stability, and resiliency are examined in model ecosystems that simulate the microbial habitat used by NASA for maintenance of atmospheric conditions and food production in long-term space missions.