Isolation of actinobacteria with ability to degrade oil of wastewater from combined cycle power plants

Increasing petroleum hydrocarbons pollution due to the continuous and increasing demand for oil and related products and the significant harmful effects of these pollutants on terrestrial and marine ecosystems, has caused much more attention and concern in recent years. Lubricating and cooling oils, which are used in industries such as combined cycle power plants to lubricate turbine bearings, generators and compressors, cause the wastewater of these industries to become oily. As regards these oily wastewaters can contain lethal and difficult degradable toxic substances, such as polyaromatic hydrocarbons, phenol, etc., if discharged to marine and terrestrial environments, they will have harmful effects on living organisms. The aim of the present study was to isolate and identify lubricating oil-degrading bacteria from oily wastewater of a combined cycle power plant. For this purpose, first, to enrich the oil-degrading bacteria, some wastewater of the combined cycle power plant was added to the bacterial liquid culture medium with equal volume. After incubation and growth, the bacteria were transferred to a culture medium containing lubricating oil and without any other carbon source. Then the oil-degrading bacteria were purified using a solid culture medium and the effects of temperature and pH on their growth were investigated. PCR and sequencing of the ۱۶S rRNA gene showed that the oil-degrading bacterium belonged to the Actinobacteria. In the culture medium containing oil as the only source of carbon, the temperature range of bacterial growth was ۲۰ to ۴۰ ° C and the pH range of growth was between ۷ and ۸. Optimal bacterial growth occurred at ۳۵ ° C and pH ۸. The results of this study indicate that the actinobacterial isolate obtained in this research can be used for bioremediation of oily wastewater of combined cycle power plants.

کلیدواژه ها:

Bioremediation ، Hydrocarbon ، Oily wastewater ، Actinobacteria