Bioremoval of naphthalene and phenanthrene by an indigenous bacterial consortium

Bioremoval of naphthalene and phenanthrene by an indigenous bacterial consortium

Polycyclic aromatic hydrocarbons (PAHs) which consist of two or more fused benzene rings are the extensive group of organic pollutants. These pollutants may cause serious risks for human health and environment. They have carcinogenic, mutagenic and toxic properties. The remediation technologies of pollutants are based on physical, chemical and biological methods. Recently, bioremediation has gained more attention than other methods. In this study a consortium of six bacterial isolates from oil-contaminated soils in the North East of Iran were used for biodegradation of phenentrene and naphtalene. According to the 16s rRNA sequence comparative data in Gene Bank, these isolates were identified as Pseudomonas zhaodogensis, Bacillus cereus, Bacillus anthracis and Pseudomonas putida. The efficiency of the consortium of six LB broth growing bacteria for biodegradation of 100 ppm naphthalene and phenanthrene after 5 days of treatment was 80% and 70% by UV spectrophotometric analysis, respectively. Also, gas chromatography (GC) analysis was done on samples containing 100 ppm phenanthrene after 1, 3 and 5 days. According to these analyses, the biodegradation level of phenanthrene was 32.4%, 50% and 69.57%, respectively. The phenanthrene biodegradation amount on the fifth day based on GC was similar to the value based on UV spectrophotometric analysis (70%). These results demonstrated that this consortium has a promising application in bioremediation of PAHs