Biodegradation of selected polycyclic aromatic hydrocarbons by axenic bacterial species belonging to the genera Lysinibacillus and Paenibacillus.

Document Type : Regular Paper

Authors

1 Department of Biological Sciences, School of Natural and Applied Sciences College of Science and Technology, Covenant University, KM 10 Idiroko Road, Canaan Land, PMB 1023 Ota, Ogun State, Nigeria.

2 Department of Microbiology, University of Lagos, Lagos Nigeria

Abstract

The quest for competent degraders of recalcitrant polynuclear aromatic hydrocarbons (PAHs) for use in sustainable bioremediation technology has justified the execution of this work. In this study, three bacterial strains (FB-1, FB-2 and FB-3) were isolated from former industrial site in Bloomington, Indiana. The catabolic versatility of these obtained strains were evaluated on some selected PAH- naphthalene, anthracene, fluoranthene and pyrene. Using the 16S r RNA sequencing analyses, our strains belonged to the family Firmicutes wereby, strain FB-1 was identified as Lysinibacillus sp. FB-1, strain FB-2 as Bacterium FB-2 and strain FB-3 as Lysinibacillus fusiformis FB-3. The biodegradation of the selected PAHs was determined using gas chromatography and the calculated percentage utilization of the selected PAHs varied between 97 to 4%. We further determined the mean biodegradation rates for fluoranthene when supplemented with molasses. The mean biodegradation rates were between (mgL-1) 0.214± 0.006 -0.318 ± 0.002, while MS-fluoranthene only ranged between (mgL-1) 0.210 ± 0.056 - 0.437± 0.176. However, with ANOVA at 5% (P< 0.05) there seemed to be no significant difference in the mean biodegradation rates between both media. These findings may have practical and ecological prospects in designing and improving bioremediation of polycyclic aromatic hydrocarbon contaminated sites..

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