Degradation of four phenylurea herbicides by mixed populations of microorganisms from two soil types

Abstract

The metabolism of four substituted urea herbicides by microbial populations from two soils was investigated. The herbicides were two dimethylurea herbicides (fluometuron and chloroxuron) and two methoxymethylphenylurea herbicides (metobromuron and chlorbromuron), and the two soils used were Louisiana Commerce Loam and Indiana Silt Loam. The dimethyl compounds were successively N-demethylated by microorganisms from both soils. N-demethylation of the methoxymethyl herbicides, however, was significant only in the Louisiana soil, while N-demethoxylation was found in only trace amounts in all the cultures. Metabolism of these herbicides apparently was predominantly via direct hydrolysis to the aniline, which in turn underwent further transformations.