Enhanced biodegradation of carbofuran in soil with a history of repeated applications of carbofuran and characterization of bacterial degraders isolated from the soil

Carbofuran is a broad-spectrum N-methylcarbamate insecticide used to control certain soil borne insects and nematodes. Enhanced biodegradation of carbofuran has been attributed to the loss of pesticidal efficacy in soil with a history of carbofuran use. Microorganisms are responsible for enhanced degradation of carbofuran in soil. There is little information linking enhanced degradation with carbofuran-degrading microbial populations in soil profiles. One of the objectives of this research was to measure the degradation rate of carbofuran in soil related to carbofuran use in soil. Soil samples were collected from a site in Florida that had either a previous history or no history of exposure to carbofuran. Mineralization rates of carbofuran in soils collected from different soil depths were measured using (;The second objective was to measure changes in the carbofuran-degrading microbial populations in soils as a function of carbofuran treatment history and soil depth. Numbers of microorganisms capable of mineralizing (;The final objective was to isolate and characterize carbofuran-ring-degrading bacteria. Three bacteria were isolated from soil and identified as Sphingomonas sp. according to their fatty acid methyl ester profiles. Growth of these isolates was determined using the Petroff-Hausser bacteria counter technique. Metabolites of carbofuran were determine using (...