EPTC DEGRADATION BY ISOLATED SOIL-MICROORGANISMS

Microorganisms capable of degrading the herbicide EPTC (S-ethyl N,N-di propylcarbamothioate) were isolated from three soils with and without histories of carbamothioate use. All EPTC-degrading isolates belonged to the genus Rhodococcus. All three isolates in pure culture systems d egraded 50 mu g mL(-1) of technical EPTC in as little as 14 h at low c ell densities and used the molecule as a sole source of carbon and ene rgy. Growth of the isolates in rich media led to the frequent loss of EPTC-degrading ability, although plasmids encoding for EPTC degradatio n could not be identified. [C-14]-EPTC experiments suggested that the degradation of EPTC proceeds by initial attack at the carbonyl Linkage , followed by degradation of the dipropylamine side chain.