Properties of six pesticide degradation plasmids isolated from Alcaligenes paradoxus and Alcaligenes eutrophus

Abstract

Biophysical and genetic properties of 6 independently isolated plasmids encoding the degradation of the herbicides 2,4-dichlorophenoxyacetic acid and 4-chloro-2-methylphenoxyacetic acid are described. Four of the plasmids, pJP3, pJP4, pJP5 and pJP7, had molecular masses of 51 Mdaltons, belonged to the IncP1 incompatibility group and transferred freely to strains of Escherichia coli, Rhodopseudomonas sphaeroides, Rhizobium sp., Agrobacterium tumefaciens, Pseudomonas putida, P. fluorescens and Acinetobacter calcoaceticus. These 4 plasmids conferred resistance to merbromin, phenylmercury acetate and mercuric ions, had almost identical restriction endonuclease cleavage patterns and encoded degradation of m-chlorobenzoate. The 2 other plasmids, pJP2 and pJP9, did not belong to the IncP1 incompatibility group, had molecular masses of 37 Mdaltons, encoded the degradation of phenoxyacetic acid and possessed identical restriction endonuclease cleavage patterns.