Development of a Quantitative Structure-Activity Relationship (QSAR) for Prediction of Biodegradation Kinetics of Polycyclic Aromatic Hydrocarbons (PAHs)EPA Grant Number: U915553
Title: Development of a Quantitative Structure-Activity Relationship (QSAR) for Prediction of Biodegradation Kinetics of Polycyclic Aromatic Hydrocarbons (PAHs)
Investigators: Wammer, Kristine H.
Institution: Princeton University
EPA Project Officer: Jones, Brandon
Project Period: August 1, 1999 through August 1, 2002
Project Amount: $102,000
RFA: STAR Graduate Fellowships (1999) RFA Text | Recipients Lists
Research Category: Academic Fellowships , Engineering and Environmental Chemistry , Fellowship - Engineering
The objective of this research project will be to use quantitative structure-activity relationship (QSAR) analysis to predict biodegradation rates of polycyclic aromatic hydrocarbons (PAHs) and to help elucidate the relationship between molecular structure characteristics and biodegradation rates.
The first step of this research project will be to explore the potential of developing a PAH biodegradation QSAR by examination of existing PAH biodegradation data and their correlation with molecular descriptors. This will be followed by development of a high-quality self-consistent database of biodegradation kinetic parameters for monocyclic and polycyclic aromatic hydrocarbons in aqueous systems, and use of these new data to develop and validate a QSAR model. Measurements of kinetic parameters will be performed in experiments with a given substrate as the sole carbon and energy source. These experiments will be designed to control for any confounding physical and chemical processes, so that accurate information is obtained about biodegradation in an aqueous phase without bioavailability constraints. The experiments will be performed in a series of batch reactors, each of which will be sacrificed to obtain a concentration measurement at a point some time from the onset of the experiment. Detection of the concentration of the substrate will be completed using a high performance liquid chromatograph (HPLC) equipped with a diode array ultraviolet (UV) detector and a fluorescence detector. Biomass concentration will be measured by a Bradford protein assay. During the period that these biodegradation experiments are being performed, molecular modeling techniques will be examined to provide alternative means of characterizing molecular structure and providing descriptors for QSAR modeling. Finally, insights gained from model development will be used to infer what the most important molecular characteristics are for determining biodegradation rates of these compounds. It is possible that we will be able to determine which steps in the biodegradation process are rate-limiting.
This experiment will provide a prediction of biodegradation rates of PAHs in the environment, and will help to broaden the scientific understanding of the relationship between molecular structure characteristics and biodegration rates.