This project supports collaborative research between Dr. Rasul Chaudhry, Department of Biological Sciences, Oakland University, Oakland, Michigan and Dr. Narayan Roy, Department of Biochemistry and Molecular Biology, University of Rajshahi, Bangladesh. They plan to study certain enzymes that degrade pesticides. The PIs have studied microbial degradation of carbamates and isolated microorganisms that can degrade these chemicals. Microorganisms either hydrolyze or oxidize the chemicals. Hydrolytic processes are less efficient and partially degrade pesticides, whereas oxidation reactions involved in degradation of carbamates are efficient, but more complex. The goal of the study is to determine the molecular mechanism of microbial oxidation of carbofuran. Using a variety of biochemical and molecular biology techniques, the PIs will test the following hypotheses: 1. A mixed function oxygenase, carbofuran hydroxylase, catalyzes the reaction of carbofuran to 4-hydroxycarbofuran. 2. A cytochrome P-450 or another unknown cofactor is involved in the electron transport circuit from NADPH to molecular oxygen. The following four specific aims will be pursued: 1. Purify the enzyme complex responsible for hydroxylation of carbofuran, 2. Characterize the purified enzyme, 3. Determine the components of the hydroxylase and their interactions responsible for catalyzing the reaction, and 4. Investigate the diversity of pesticide-degrading microorganisms. A combined expertise of the collaborating investigators, a biochemist and a molecular biologist will help solve the novel mechanism of induction and functioning of the hydroxylase complex that is key to the effective inactivation of carbofuran in the environment.
Scope and broader impact: Pesticides such as carbofuran are the major group of chemicals that are used in large amounts for improving productivity and quality of crops. While these chemicals are vital to agriculture, human exposure to these pesticides through consumption of foods or drinking water has been suggested to play a key role in the early onset of neurological diseases, old age diseases such as Alzheimer's disease, immunological and reproductive disorders as well as an increase in the risk of non-Hodgkin lymphoma. This study will substantiate and extend our understanding of microbial metabolic diversity. It will also help develop new strategies for their safe and effective use as well as disposal.
