Isolation and Evaluation of Environmental Bacteria with the ability to bioremediation of Flourene and Benzo (a) pyrene from Khazar lake.

Abstract

Introduction: Among the ways of decomposition of Poly Aromatic Hydrocarbons (PAHs) pollutants, biodegradation is very important. Due to their high concentration in the Caspian Sea, it is important to identify native Caspian bacteria that can biodegrade PAHs. Aim: Separation, identification and investigation of some native bacterial species of the Caspian Sea with the power of organic matter decomposition Methods: The bacteria were isolated from the aqueous sample by marine agar culture medium and sea water medium. To isolate bacteria capable of decomposing PAHs, MSM culture medium enriched with fluorene and benzoin (a) pyrene was used. Qualitative analysis of the biodegradation of the above compounds was performed by 3 MSM culture media enriched with one PAH as the only carbon source. To identify the bacteria, sequencing of the 16S rRNA fragment was used and a quantitative analysis of the degrading power of these materials was performed by the UV method. Results: Five bacteria with titles (TBZ2, TBZ-SF2, TBZ-F1, TBZ-F2 TBZ1) with the ability to use the mentioned PAHs were isolated, which belong to the genera Pseudomonas, Shewanella, Photobacterium and Mycobacterium. TBZ2 isolation can be introduced as a new bacterial species. Quantitative studies of the decomposition of PAHs on the TBZ2 isolate belonging to the genus Pseudomonas have shown a significant difference in growth between the control group and use of benzo (a) pyrene as the only source of organic carbon. (p≤ 0.05) Conclusion: The native bacteria of the Caspian Sea have an effective role in the decomposition of PAHs Some of the process of clearing of the Caspian Sea of these pollutants is done by these bacteria.