[Degradation of polychloroaromatic insecticides by Pseudomonas aeruginosa containing biodegradation plasmids]

The work was aimed at studying the degradation of DDT, its metabolites and analogs by BS 816 and BS 827 strains constructed on the basis of Pseudomonas aeruginosa 640x strains and carrying biodegradation plasmids pBS2 and pBS3, respectively. DDT and kelthane were degraded by the BS 816 strain at a greater rate than by the parent culture. The investigation of enzymes involved in the oxidation of the aromatic cycle has shown that the plasmid-carrying strains possess the activity of metapyrocatechase and salicylate hydroxylase which is absent in P. aeruginosa 640x. The activity of pyrocatechase increased. In contrast to the parent strain where homogentisate induced only homogentisate oxygenase, this compound induces also metapyrocatechase in the constructed strains.