Plasmid involvement in the degradation of polycyclic aromatic hydrocarbons by a Beijerinckia species.

A Beijerinckia species, capable of oxidizing phenanthrene, biphenyl and other polycyclic aromatic hydrocarbons, was shown to contain two plasmids that were designated pKGl and pKG2. The molecular masses of plasmids pKG1 and pKG2, as determined by electron microscopy, were approximately 147 X 10(6) and 20.8 X 10(6) daltons, respectively. Growth of the organism on benzoate led to the isolation of strains that had lost the ability to grow with phenanthrene and biphenyl. All of the Phn-, Bph- strains had also lost the smaller plasmid, pKG2. The results presented suggest that plasmid pKG2 is responsible for the synthesis of enzymes involved in the degradation of phenanthrene and biphenyl.