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Biodegradation of the Organophosphate Methyl Parathion by Recombinant Escherichia coli
Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan www.asabe.orgCitation: Paper number 037033, 2003 ASAE Annual Meeting . (doi: 10.13031/2013.15344)
Authors: Adriana Z. Diaz, Jiyeon Ha, Cady R. Engler, James R. Wild
Keywords: Methyl parathion, Biodegradation, OPH, Recombinant Escherichia coli, Bioremediation
The widespread use of organophosphate (OP) compounds, such as methyl parathion (MP) in agricultural, urban, and industrial applications poses an environmental challenge for remediation and detoxification of OP neurotoxins. It has been suggested that biodegradation becomes an attractive option for destruction of OP since it utilizes a natural process and offers the potential for less costly treatment. However, biodegradation rates usually are slow because the compound being destroyed is toxic or recalcitrant. This study investigates hydrolysis of MP using a recombinant strain of Escherichia coli, which contains the opd gene for organophosphate hydrolase (OPH). The effect of biomass concentration up to 100 g/L was evaluated for degradation of MP at a concentration of 1g/L. Results show that the concentration of biomass for maximum reactor productivity, was 25 g/L. With this biomass concentration, the degradation rate was 69 3 mol/Lmin. The effect of substrate concentration on hydrolysis kinetics also was evaluated. Over a range of substrate concentrations up to 2 g/L, substrate inhibition did not occur. MP degradation was confirmed by reduction of the HPLC peak for MP and the appearance of the p-nitrophenol (PNP) peak, which increased at about the same rate as MP was degraded.(Download PDF) (Export to EndNotes)