Microbial Transformation of Fluorinated Environmental PollutantsEPA Grant Number: R830249
Title: Microbial Transformation of Fluorinated Environmental Pollutants
Investigators: Loeffler, Frank E.
Current Investigators: Loeffler, Frank E. , Sohn, Rosa , Song, Ryoung
Institution: Georgia Institute of Technology
EPA Project Officer: Lasat, Mitch
Project Period: September 1, 2002 through August 31, 2004 (Extended to August 31, 2005)
Project Amount: $198,936
RFA: Futures Research in Natural Sciences (2001) RFA Text | Recipients Lists
Research Category: Ecological Indicators/Assessment/Restoration , Land and Waste Management , Hazardous Waste/Remediation
Fluorinated organic compounds (FOCs) are released into the environment in significant amounts by anthropogenic activities. Despite liberal use of FOCs, these compounds have received relatively little attention from scientists, regulatory agencies, and the public because they were perceived as biologically inert and therefore not likely to have an impact on ecosystem health. Recent toxicological studies, however, indicate that fluorinated compounds are not biologically inert, and may pose a risk to ecosystem function and stability, as well as to human health. Hence, the overall goal of the proposed research effort is to elucidate the potential of microorganisms to degrade and detoxify fluorinated environmental pollutants under aerobic and anaerobic conditions. Specifically we will investigate (i) whether FOCs are favorable electron acceptors for halorespiring populations under anaerobic conditions, (ii) demonstrate that defluorination of polyfluorinated hydrocarbons is feasible using model compounds and model organisms, and (iii) develop defluorinating microcosms and enrichment cultures from a collection of soil, aquifer, and sediment samples.
To evaluate whether or not FOCs can serve as favorable electron acceptors under anaerobic conditions, reductive defluorination will be tested with available chlororespiring pure and mixed cultures. In addition, a collection of aquifer, soil, and sediment materials will be tested for reductive defluorination activity. Hydrogen consumption threshold measurement will be performed to verify whether FOCs serve as metabolic electron acceptors under anaerobic conditions. To explore the strategies of aerobic microorganisms to attack (poly)fluorinated hydrocarbons, model compounds will be used in pure culture studies, and additional FOC-degrading cultures will be derived from a collection of soil, aquifer, and sediment samples.
The outcome of this research will shed light on the potential for microbial populations to transform and degrade FOCs under aerobic and anaerobic conditions. This data is critical to evaluate the risk associated with the continuous use of FOCs, and will provide a foundation for science-based risk assessment of FOCs in the environment. With this information, regulatory agencies like the EPA can provide recommendations to industries that use or manufacture FOCs, impose meaningful exposure limits, and inform the concerned public as to the truths and fallacies of FOCs. In addition, this work will derive defluorinating cultures, which will be available for further more detailed studies on the physiology and phylogeny of the defluorinating populations.