Biodegradation of Bonnylight crude oil by locally isolated fungi from oil contaminated soils in Akure, Ondo state

Aim: This present investigation was conducted to determine the capability of fungi isolated from soil samples collected from two automobile workshopsto bioremediate Bonnylight crude oil. Methodology and Results: The fungi present on the soil samples collected from two automobile workshops in Akure, Nigeria were investigated using standard microbiological techniques. These fungal isolates were screened for the ability to degrade Bonnylight crude oil. The bioremediation of Bonnylight crude oil was observed spectrophotometrically using the broth culture (non-harvested cells) and harvested cells of the fungi isolated from the contaminated sites for a period of 20 days on minimal salt broth. Mycotypha microspora, Penicllium italicum, Botryris cinerea, Gliocladium deliquescence, Verticillium albo-atrum and Aspergillus niger were isolated from the contaminated site while Neurospora crassa, A. parasiticus, A. niger and Gonatobotryum apiculatum were isolated from uncontaminated sites. All the fungal isolates were capable of active degradation in varying degrees. Conclusion: The study shows that all the isolated fungi were capable of degrading the crude oil in varying degrees. The active crude oil utilizing fungi in this study were Aspergillus niger (both harvested and non harvested cells) and Gliocladium deliquescence (non harvested cells) and Penicillium italicum (harvested cells). Aspergillus niger has best degrading ability than other fungi in non harvested and harvested cell condition. However, non harvested cells recorded the higher degradative ability than harvested cells. Therefore, non harvested cells can be employed in bioremediation of Bonnylight crude oil. Significance and Impact of Study: The fungi isolated from automobile mechanic workshops contaminated soil can be exploited in the bioremediation of Bonny Light crude oil.