Biodegradation of different concentrations of crude oil by the bacterial consortium isolated from mangrove sediments

Background and Aim : Mangrove forests are one of the most valuable ecosystems in the world. Since the importance of mangrove forests as a valuable ecosystem in southern Iran, it is necessary to investigate the bacterial potential of mangrove forests in the biodegradation of oil pollutants. The aim of this study was to investigate the biodegradation of various concentrations of crude oil by the bacterial consortium enriched from Minab Mangrove forest sediments.Methods : Sediment and water collected from the Minab Mangrove forest were added to the mineral salt medium with crude oil as the only source of carbon and energy and crude oil-degrading bacteria were enriched by successive cultivation. The bacterial consortium was then cultured in a nutrient broth and after ۲۴ hours the bacterial consortium were precipitated and inoculated to the mediums containing different concentrations of crude oil (۰.۵, ۱, ۲ and ۳) with a final OD of ۰.۱۵Results : The results showed that the enriched bacterial consortium was able to consume crude oil. At the end of the experimental period, almost all crude oil degraded in treatments containing ۰.۵% and ۱% crude oil. In the treatment containing ۲% crude oil, ۷۸.۵% of the crude oil was consumed and the lowest crude oil biodegradation was measured in the ۳% crude oil treatment.Conclusion : In general, the bacterial consortium had a significant ability to degradation different concentrations of crude oil. As crude oil concentrations increased, the rate of biodegradation decreased significantly, indicating a decrease in bacterial growth at high concentrations of oil. It is also recommended to determine the optimal biodegradation conditions to increase the biodegradability efficiency.

کلیدواژه ها:

biodegradation ، mangrove ، oil pollution