BACTERIAL DESULFONATION OF THE ETHANESULFONATE METABOLITE OF THE CHLOROACETANILIDE HERBICIDE METAZACHLOR

Metazachlor (R-CH2-Cl), a chloroacetanilide herbicide, is converted in soil to products including the ethanesulfonate metabolite (R-CH2-SO3- ; BH 479-8), Nothing is known about the degradation of the ethanesulfo nates of this class of herbicides. We used inocula derived from five s ources for enrichment cultures to utilize R-CH2-SO3- as a sole sulfur source for the growth of microorganisms. Each culture yielded bacteria that caused the disappearance of R-CH2- SO3- and the formation of a p roduct identified as the glycolate metabolite (R-CH2-OH; BH 479-1) by mass spectrometry. A pure culture, strain HL1, was isolated, and this bacterium quantitatively desulfonated R-CH2-SO3-, the sulfur being rec overed in cell protein. Recovery of the organic moiety was usually abo ut 80%. A second ethanesulfonate (R'-CH2-SO3-) and two alkylsulfonates , but not taurine, were utilized by strain HL1 as sulfur sources.