Plasmid-mediated dimethoate degradation in Pseudomonas aeruginosa MCMB-427.

AIMS

To investigate the genetics of dimethoate degradation in Pseudomonas aeruginosa MCMB-427.

METHODS AND RESULTS

Pseudomonas aeruginosa MCMB-427 demonstrated the ability to degrade dimethoate, a synthetic organophosphate insecticide. Total DNA preparation of MCMB-427 revealed the presence of a 6.6 kbp plasmid (designated as pDMD427). Escherichia coli NovaBlue transformed with plasmid pDMD427 subsequently acquired the ability to degrade dimethoate. Curing of the plasmid by plumbagin or ethidium bromide resulted in the loss of ability of MCMB-427 to degrade dimethoate. Plasmid pDMD427 was stable in MCMB-427 over 20 passages without selection. Genes encoding resistance to norfloxacin and cobalt were also located on plasmid pDMD427.

CONCLUSION

The ability of Ps. aeruginosa MCMB-427 to degrade dimethoate is plasmid-mediated and transferable to other strains.

SIGNIFICANCE AND IMPACT OF THE STUDY

As far as is known, this is the first report of plasmid-mediated dimethoate biodegradation. This study contributes significantly towards an understanding of the genetics of bacterial dimethoate degradation.