Bioremediation of Organophosphorus Compounds


Biochemical and molecular identification of seven paraoxon-degrading Pseudomonas species (Pseudomonas aeruginosa and Pseudomonas putida) collected from the greater Houston area. Paraoxon is an organophosphorous compound used as a pesticide as well as in chemical weapons that acts as an aceytlcholinesterase inhibitor resulting in considerable nerve damage or death in humans upon exposure.

This project identifies the presence of paraoxon-metabolizing bacteria in contaminated soils. It details an accurate and repeatable system of identification through both molecular (16S rRNA) and biochemical testing (API20NE, FAME) for paraoxon-degrading bacterial species. Molecular identification can be difficult if isolates are species that belong to large genera of closely related organisms. By incorporating biochemical data into the system, a more accurate species identification is achieved in a relatively short period and less cost than it would take to analyze sequence data for multiple genes.


Seven Pseudomonas isolates capable of metabolizing paraoxon to p-nitrophenol were identified through 16 rRNA sequencing, API20NE biochemical testing, and fatty acid methyl ester (FAME) analysis. Results from these studies will ultimately provide phylogenetic makeup of microbial communities that degrade toxic compound and contribute to our understanding of cause and effect relationship between beneficial genetic adaptation of microbes to toxic compounds and to eventually develop strategies for effectively treating environmental pollution.