Biodegradation of crude oil by Scenedesmus obliquus and Chlorella vulgaris growing under heterotrophic conditions

One of the major environmental problems nowadays is petroleum hydrocarbon contamination, particularly in the zones of petroleum production, and petrochemical industries. This study was carried out to evaluate the potential of two green algae Scenedesmus obliquus and Chlorella vulgaris to degrade crude oil. Experiments were performed by incubating algal cultures with 0.5, 1, 1.5 and 2% crude oil for incubation period of 15 days under heterotrophic conditions. It was found that Scenedesmus obliquus and Chlorella vulgaris performed the highest biodegradation rate of crude oil when 0.5 and 1% oil was applied. The highest growth of S. obliquus was attended with 0.5% crude oil; while it was recorded at 2% for C. vulgaris, under the same heterotrophic conditions. Both algae could grow and degrade oil effectively when incubated with low concentrations of oil.

► Ability of green algae to grow under heterotrophic conditions.
► Green algae are able to use crude oil as carbon source.
► Green algae can degrade n-alkane and PAHs.
► We propose a model for crude oil biodegradation by microalgae.