The Organophosphorus pesticides are widely used for agricultural and domestic purposes due to their relatively low persistence in the environment. Chlorpyrifos-methyl (CM) is used at a rate of over 14 million pounds per year in US agriculture, ranking it as the second most heavily used pesticide. This study aimed at isolating bacteria from soil and determining their ability to degrade CM and identify the intermediates in culture broth. Bacteria capable of degrading CM was isolated by enrichment culture. Chryseobacterium sp. strain KR200 degraded CM up to 91.58% in 7days. Studies with CM in liquid culture of Chryseobacterium sp. strain KR200 demonstrated that the isolate hydrolyzed CM to 3,5,6-trichloro-2-pyridinol, and utilized this compound for growth and energy. We performed SDS-PAGE and two-dimensional gel electrophoresis and identified proteins whose expression pattern is affected by CM using mass spectrometry. The results revealed various proteins that can be grouped according to their respective cellular function. These results highlight the potential of this bacterium to be used in the clean up of contaminated pesticide waste in the environment.

• Jun-Ran Kim(WCU Biomodulation Major, Department of Agricultural Biotechnology, Seoul National University, Research Institute for Agriculture and Life Science, Seoul National University)
• Young-Joon Ahn(WCU Biomodulation Major, Department of Agricultural Biotechnology, Seoul National University)