Isolation and identification of phenol-degrading bacteria in the industrial wastewater from the coal tar mine of Zarand in Iran

Phenol is one of the major aromatic and carcinogenic pollutants. Phenol degrader bacteria from the coal tar mine of Zarand have been identified with the bacterial growth assayed in different concentrations. Four samples were collected from different sites of the mine. Total heterotrophic and phenol-degrading bacteria were quantified and the results indicated that most of phenol degrader bacteria aggregated in the sludge aggregate site. Eleven phenol degrading bacteria were isolated that were capable of degrading 200 ppm phenol in 7 d, 6 bacterial strains were selected for capability of growth on more concentration of phenol and biochemical characteristics. Finally, two strains named isolates 42P and 53P were selected for analysis of 16S rRNA sequences. Strain 42P belongs to Chryseobacterium indologenes AHB42P while Strain P53 belongs to Pseudomonas putida AHB53P which is capable of degrading 1,800 ppm phenol. The results support the idea that environments in mines can serve as a source of bacterial strains for purposes of bioremediation.