Homologous plasmids from soil bacteria encoding D,L-halidohydrolases

We isolated and characterized D,L-halidohydrolases from five different soil bacteria. Three of these bacterial strains bear plasmids with sizes of approximately 60 kb. Curing and mating experiments indicated that these three plasmids pFL160, pFL170, and pFL190 encoded a dehalogenase. Owing to their biochemical characterization, these halidohydrolases were closely related among each other and to the DhlIV halidohydrolase, encoded by plasmid pFL40 from Alcaligenes xylosoxidans ssp. denitrificans ABIV. Restriction enzyme patterns as well as DNA-hybridization experiments with an internal fragment of dhlIV revealed a high degree of homology among each of these four plasmids and their dehalogenase genes.