Biodegradation of crude petroleum and petroleum products by fungi isolated from two oil seeds (melon and soybean)

Crude petroleum oil degrading fungi were isolated from two oil seeds, Cucumeropsis mannii (melon) and Glycine max (soybean) seeds in the presence and absence of petroleum fumes. An assessment of the relative ability of each fungus to degrade crude petroleum, diesel and kerosene on minimum salt solution was done using change in optical density read on spectrophotometer. Twenty-one fungal species (14 genera) were isolated alltogether during this experiment. These include sight species of Aspergillus; one species each of Botryodiplodia, Bipolaris, Cladosporium, Cunnighamella, Dreschlera, Fusarium, Helminthosporium, Macrophomina, Mucor, Paeciliomyces, Penicillium, Rhizopus and Talariomyces. It was evident that most of the fungi tested were able to biodegrade the crude petroleum oil, though at different rates. Bipolaris had a low rate of biodegradation of the petroleum oil of all the fungal species isolated Botryodiplodia theobromae had the highest degrading ability on the crude oil, while Aspergillus flavus had the least after 40 days of incubation. Aspergillus flavus had the highest ability to biodegrade diesel while A. niger had the least ability. In kerosene, Macrophomina phaseolina had the highest ability while A. niger had the least ability to biodegrade it. There was fluctuation in the growth pattern of the fungi in the petroleum oil medium. The implication of these are discussed.