[Comparative study of the plasmids controlling naphthalene biodegradation by a Pseudomonas culture]

The object of this work was to study 25 Pseudomonas strains growing in a medium with naphthalene as a sole carbon source. Naphthalene catabolism was controlled by conjugative plasmids in 14 strains. The molecular mass of the plasmids was rather big, from 60 to 130 MD. The plasmids were classified in terms of their incompatibility group were assigned to the P-7 and P-9 groups five to each group. The incompatibility group could not be determined in four plasmids. The character of naphthalene catabolism controlled by the plasmids implies that only two of the plasmids control naphthalene oxidation via the "ortho" pathway of catechol cleavage which is an intermediate product in the oxidation of naphthalene. Just as most of the so far known plasmids controlling naphthalene biodegradation, seven of the plasmids studied in this work controlled naphthalene oxidation via the "meta" pathway of catechol cleavage.