Microbial Consortium for Polycyclic Aromatic Hydrocarbons Degradation from Petroleum Hydrocarbon Polluted Soils in Rivers State, Nigeria

Abstract

The study investigated the distribution of polycyclic aromatic hydrocarbon (PAH) degraders across two different petroleum hydrocarbon-polluted sites in the Niger Delta, Nigeria, and the ability of the reconstituted indigenous consortium to utilize these PAHs. Microorganisms were isolated after sample enrichment in naphthalene and anthracene, and biosurfactant production was measured using the emulsification index technique. PAH concentrations of approximately 6000 mg/kg and 9000 mg/kg in Tombia and Bodo were higher than the Department of Petroleum Resources (DPR) intervention limit of 40 mg/kg. The pH, soil texture and high conductivity affected microbial distribution significantly. A total of 12 bacteria from the genera Bacillus, Pseudomonas, Micrococcus and 3 fungal isolates (Fusarium, Aspergillus and Penicillium) from the 2 sites were able to utilize naphthalene and/or anthracene as sole carbon source. While the Tombia site had more microorganisms capable of PAH degradation with the redox indicator 2, 6-dichlorophenol indophenol (DCPIP) (10 bacterial and 3 fungal species), two bacterial species from Bodo were able to produce biosurfactant. The findings of this study indicate that indigenous microbes in the polluted sites are catabolically active and could be further stimulated for an effective eco-friendly and green removal of PAHs from oil-polluted soils while combined.