Abstract: One strain which could use phenanthrene as sole carbon source was isolated from petroleum and heavy metal containminated soil,collected from old industry depot in northeast China.Based on morphological and physio-biochemical characteristics and homology identification of 16S rDNA sequence,the strain ZX16 was identified as Sphingomonas aromaticivorans.In the mineral salts medium under initial phenanthrene concentration of 1 500 mg/L the removal rates of phenanthrene was 98.2% within 72 h. Tolerance of ZX16 to phenanthrene exceeds 2 500 mg/L and ZX16 was relatively to the cell growth at neutral pH value. The effect of different heavy metal on degrading rate was Cu^2＋＞Cd^2＋＞Zn^2＋＞Pb^2＋in order. Microstructure of cell surface screening by Atomic Force Microscopy shows that the volume and morphous of strain have significant changes and the surface also changes from rough to smooth and glossy.

Key words: phenanthrene, combined pollution, atomic force microscopy, degradation, phenanthrene, combined pollution, atomic force microscopy