Abstract

 Oilfield wastewater not adequately treated contains organic and inorganic substances including polycyclic aromatic hydrocarbons (PAHs). PAHs are toxic and are not easily degraded by microorganisms. Therefore, this study investigated the role of fungi in the biodegradation of PAHs in oilfield wastewater. Oilfield wastewater was collected from an onshore oil producing platform and biodegradation of polycyclic aromatic hydrocarbons was investigated using standard methods. Fungi were isolated from oilfield wastewater polluted soils obtained from the vicinity of the oil producing platform. The fungal isolates were identified molecularly using internal transcribed spacer (ITS) and identified with accession numbers as Aspergillus niger (MN094359), Aspergillus sydowii (MN094361) and Fusarium lichenicola (MN094360). Experimental control set-up and treatments contained 125 ml of oilfield wastewater. Each of the single treatments had 12.5 ml of mineral salt medium which contained the fungal isolates. Mixed culture treatment contained 4.17 ml each of the fungal isolates while the control set up contained oilfield wastewater only. The experimental samples were periodically analyzed at day 7 and day 21 intervals for polycyclic aromatic hydrocarbon degradation using Gas Chromatography (GC). The total amount of PAHs in oilfield wastewater on day 1 was 101.72992 mg/l. The amount of PAHs in control on day 7 and 21 was 93.01704 mg/l and 75.40663 mg/l, respectively. Aspergillus niger, Aspergillus sydowii, Fusarium lichenicola and mixed culture fungi on day 21 recorded 27.0136, 27.3887, 34.7772 and 15.02925 mg/l with percentage removal of 73.4%, 73.1%, 65.8% and 85.2%, respectively. There was a significant difference between the treatment options and the control on day 7 and 21 at P≤0.05. The results therefore revealed significant reduction of PAHs in the treatment options. In addition, there was complete removal of naphthalene and chrysene by Aspergillus niger and mixed culture while Aspergillus sydowii showed removal of Chrysene only. In conclusion, fungi have great potentials in degradation of PAHs and in remediation of PAHs contaminated environments, different species of fungi have the ability to attack one or more components of PAHs and complete degradation of PAHs was best achieved by mixed fungal cultures.

Keywords: Oilfield Wastewater; PAHs; Fungi; Biodegradation; GC; Naphthalene; Chrysene

References

1. Rahman KS., et al. “Enhanced bioremediation of n-alkane in petroleum sludge using bacterial consortium amended with rhamnolipid and micronutrients”. Bioresources Technology 90 (2003): 159-168.
2. Mueller JG., et al. “Effect of inoculation on the biodegradation of weathered prudhoe Bay crude oil”. Journal of Industrial Microbiology 10 (1992): 95-102.
3. Hallier-Soulier S., et al. “Detection and quantification of degradative genes in soils contaminated by toluene”. FEMS Microbiology 20 (1999): 121-133.
4. Martello A. “Biodegradation: Cleaning up with Biology and Technology” 5 (1991): 7.
5. Aleruchi O and Obire O. “Quality characteristics of an oilfield produced water and its recipient discharge pond”. E-Journal of Science and Technology4 (2018): 1-10.
6. Obire O and Okudo I. “Effects of crude oil on a freshwater stream in Nigeria”. Discovery and Innovation 9 (1997): 25-32.
7. Wemedo SA. “Bioremediation potential of oilfield produced water in a crude oil contaminated soil in Nigeria”. International Journal of Geography and Environmental Management2 (2016): 49-57.
8. Williams JO and Aleruchi O. “Biodegradation potentials of Aspergillus sydowii and Fusarium lichenicola on total petroleum hydrocarbon in an oilfield wastewater in Rivers State”. Journal of Advances in Microbiology3 (2019): 1-7.
9. Saitou N and Nei M. “The neighbor-joining method: A new method for reconstructing phylogenetic trees”. Molecular Biology and Evolution 4 (1987): 406-425.
10. Felsenstein J. “Confidence limits on phylogenies: An approach using the bootstrap”. Evolution 39 (1985): 783-791.
11. Jukes TH and Cantor CR. “Evolution of protein molecules”. In Munro HN, editor, Mammalian Protein Metabolism (1969): 21-132.
12. Birolli WG., et al. “Biodegradation of anthracene and several PAHs by the marine derived fungus Cladosporium sp CBMAI 1237”. Maritime Pollution Bulletin2 (2018): 525-533.
13. Davis JB and Westlake DWS. “Crude Oil Utilization by Fungi”. Canadian Journal of Microbiology, 25 (1979): 146-156.
14. Obire O. “Studies on the biodegradation potentials of some microorganisms isolated from water systems of two petroleum producing areas in Nigeria”. Nigerian Journal of Botany 1 (1988): 81-90.
15. Chaillan F., et al. “Identification and biodegradation potential of tropical aerobic hydrocarbon- degrading microorganisms”. Research in Microbiology7 (2004): 587-595.
16. Singh H. “Mycoremediation: Fungal Bioremediation”. New York: Wiley Inter science (2006): 592.
17. Bik HM., et al. “Dramatic shifts in benthic microbial eukaryote communities following the deep water horizon oil spill”. PloS One (2012).
18. Balaji V and Ebenezer P. “Optimization of extracellular lipase production in Colletotrichum gloeosporioides by solid state fermentation”. Indian Journal of Science and Technology 1 (2008):1-8.
19. Obire O and Anyanwu EC. “Impact of various concentrations of crude oil on fungal populations of soil”. International Journal of Environmental Science and Technology 6 (2009): 211-218.
20. Bento FM and Gaylarde CC. “Biodeterioration of stored diesel oil: Studies in Brazil”. International Biodeterioration and Biodegradation 47 (2001): 107-112.
21. Facundo JMR., et al. “Biodegradation of diesel oil in soil by a microbial consortium”. Water, Air and Pollution 128 (2001): 313-320.

Citation

Citation: Obire O Aleruchi O and Wemedo S A. “Fungi in Biodegradation of Polycyclic Aromatic Hydrocarbons in Oilfield Wastewater". Acta Scientific Microbiology 3.4 (2020): 220-224.

Copyright

Copyright: © 2020 Obire O Aleruchi O and Wemedo S A. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.