Isolation and study of Biodegradiation Potential of Phenanthrene degrading bacteria

Polycyclic Aromatic Hydrocarbons (PAHs) are among of potentially hazardous chemicals for environment and cause health concern. These compounds exhibit carcinogenic and/or mutagenic properties and are listed by the United States Environmental Protection Agency (USEPA) as priority pollutants. Polycyclic Aromatic Hydrocarbons are hardly degraded and therefore bioremediation is often considered as a desirable and cost effective remediation technique for soil. contaminated with them.

In this research Phenanthrene (C14H10), a three-benzene ring PAHs, was selected as a PAH representative compound and two different concentrations of Phenanthrene (100mg/kg and 500mg/kg) were studied. First, PAH-degrading microorganisms were separated and after adaptation and enrichment PAH-degrading bacteria were identified.

The results showed that removal efficiency of Phenanthrene in the samples containing pseudomonas was more than other specified bacteria. Also the most removal efficiency of Phenanthrene occurred in first 45 days of biotreatment and then decreasing trend slowed down. Other finding was that the bioremediation of the lower concentration of Phenanthrene takes shorter time compared with the higher concentration and also the comparison of Phenanthrene bioremediation by pure bacteria and Consertium indicated that, at the beginning of the process, the pace of eliminating Phenanthrene by Consertium is more than other bacteria.

Microbial analysis, based on cinfirmation tests and analytical profile index (api) 20E kit tests, showed that Pseudomonas. SPP, Bacillus, Pseudomonas aeruginosa and Acinetobacter were the bacteria, responsible for Phenanthrene degradation. Extraction was conducted by ultra sonic method and Phenanthrene concentration was measured by (HPLC).