Isolation and characterisation of a bacterial strain degrading the herbicide sulcotrione from an agricultural soil

BACKGROUND: The dissipation kinetics of the herbicide sulcotrione sprayed 4 times on a French soil was studied using a laboratory microcosm approach. An advanced cultivation-based method was then used to isolate the bacteria responsible for biotransformation of sulcotrione. Chromatographic methods were employed as complementary tools to define its metabolic pathway. RESULTS: Soil microflora was able quickly to biotransform the herbicide (DT50 ≈ 8 days). 2-Chloro-4-mesylbenzoic acid, one of its main metabolites, was clearly detected. However, no accelerated biodegradation process was observed. Eight pure sulcotrione-resistant strains were isolated, but only one (1OP) was capable of degrading…