Isolation and characterization of phenanthrene decomposing Pseudomonas sp

We have determined, isolated, and characterized Pseudomonas which are invol ved in the biodegradation of phenanthrene, a polycylic aromatic hydrocarbon , from soil contaminated with fuel oil. Isolates were determined in the stu died samples, 5 of which belong to Pseudomonas. Degradation of phenanthrene was established by forming clear zone around colonies on mineral salt medi um and 4 Pseudomonas have ability to biodegrade phenanthrene. Morphological , physiological, biochemical, chemotaxonomic, and molecular characteristics of the Pseudomonas isolates were determined. Two of phenanthrene decomposi ng Pseudomonas were found to contain plasmid, having 2.7 kb molecular weigh t. This plasmids may play a significant role on the decomposition of phenan threne. However, we think also that plasmid may be integrated to genom in p lasmid-absent phenanthrene-degrading isolates.