Isolated from oil-contaminated soil, Pseudomonas aeruginosa strain MGP-1 was identified by 16S rDNA sequence analysis and phenotypic characterisation. This strain was highly competent in medium and in soils, grew and survived well under adverse conditions. MGP-1 did not produce the pathogenic factor pyocyanin and used paraffin (C 11-40 ) as sole carbon source. It degraded eicosane (C 20 ) more efficiently than other n-alkanes, removing 60% within 16 days. An alkB gene and intermediate metabolites of mono-alcohol and lipid acid corresponding to the oxidised paraffin were detected in the cell-free extracts of MGP-1, indicating that it possessed a mono-terminal oxidation. This is the first report to demonstrate that a Pseudomonas strain is able to degrade paraffin with more than 18 carbon atoms by mono-terminal oxidation. Considering all the results, MGP-1 could be designed as a soil-born, highly competent, long chain n-alkane degrading bacterium with low or perhaps without pathogenicity.