A catabolic plasmid involved in 4-methyl-o-phthalate and 4-hydroxy-iso-phthalate degradation in Pseudomonas cepacia

Genes involved in 4-methyl-o-phthalate and 4-hydroxy-iso-phthalate catabolism reside on a 226-232 kbp catabolic plasmid termed MOP. This was confirmed by transformation and conjugation into an isogenic heat-cured (MOP-) derivative of the wild-type isolate, identified and termed Pseudomonas cepacia Pc701. Transformation confirmed the presence of Tn1 in MOP derived from Pc704, a mutant deficient in 4-methyl-o-phthalate catabolism. pCS1, a recombinant plasmid bearing MOP DNA, complemented MOP::Tn1 restoring the ability of Pc704 to grow on 4-methyl-o-phthalate. DNA-DNA hybridization using pCS1 as probe confirmed that loss of 4-methyl-o-phthalate catabolism by Pc704 was the result of Tn1 insertion into a 2.1 kbp HindIII fragment of MOP.