Background and Objective: Polycyclic Aromatic Hydrocarbons (PAHs) are the most important organic pollutants that causing multiple side effects including carcinogenic, mutagenic and toxicity. Among the aromatic compounds degrading bacteria, pseudomonas produce board spectrum of degrading enzymes and are used, as biological tools, for decreasing of PAHs. This study was done to evaluate the degradation of polycyclic hydrocarbones anthracene by using Pseudomonas aeruginusa.

Methods: In this descriptive – analytic study, sampling was collected from river estuary sediment and had cultured in Minimal Salt Medium (MSM). Pseudomonas aeruginosa was one of the isolated bacteria from river sediment which identified by molecular technique. In next step, influence of pH (6.5 and 7.5) temperature (25 and 35°C) and concentration of anthracene (150 and 200 ppm) were surveyed on anthracene biodegradation and bacterial growth during zero, 24 and 48 hours by HPLC and spectrophotometry method respectively.

Results: The results showed that the optimized condition for biodegradation included pH=7.5, 35°C and 150 ppm of anthracene. Bacterial degradation of anthracene was increased with prolong of incubation time. Biodegradation efficiency of anthracene in the presence of pseudomonas was 50% within 2 days, which indicates the ability of the bacteria for the enzymes production.

Conclusion: High growth potential of pseudomonas in unsuitable areas and due to the production of degrading enzymes, it can be used as indicator bacteria used to remove anthracene.