Detection of a methylcarbamate degradation gene in agricultural soils using PCR amplification of bacterial community DNA.
Derk-R; Karns-J; Sexstone-A
Commun Soil Sci Plant Anal 2003 Mar; 34(3-4):393-406
The carbamate insecticide carbofuran (2,3-dihydro-2,2-dimethyl-7-benofurayl-N-methylcarbamate) is biodegraded by a methylcarbamate hydrolase enzyme encoded by a methylcarbamate degradation (mcd) gene cloned from Achromobacter sp. strain WM111. A 0.4-kbp BamHI-KpnI fragment of the mcd gene was used as a DNA probe to monitor soil microbial populations capable of degrading carbofuran in soils from twelve contrasting agricultural sites, representing seven soil series from five U.S. states. Each soil was amended three times with carbofuran (200 g g-1 dry weight soil) and monitored until 90% of the carbofuran had degraded after each application. Soil bacterial community DNA was extracted and humic acid contaminants removed prior to PCR amplification of mcd. The detection limit for the probe protocol was 102 microorganisms g-1 of soil. Eight soils were mcd positive, and four were negative. Results were independently confirmed using both a Southern blot and slot blot protocol. Of the four negative soils, three exhibited accelerated rates of carbofuran degradation, suggesting that enzymes other than the hydrolase encoded by mcd were active in pesticide removal.
Agricultural-chemicals; Insect-repellents; Insecticides; Microorganisms; Microscopic-analysis; Soil-analysis; Soil-bacteria; Soil-sampling; Bactericides; Bacteriology; Bacteria; Pesticides; Pesticides-and-agricultural-chemicals
Alan Sexstone, Division of Plant and Soil Sciences, 401 Brooks Hall, PO Box 6057, West Virginia University, Morgantown, West Virginia, Morgantown, WV 26506-6057
Communications in Soil Science and Plant Analysis