Abstract

White-rot fungi have been used in various parts of the world for bioremediation of polluted sites. Pleurotus tuber-regium was noted to have the ability to increase nutrient contents in soils polluted with 1 - 40% engine-oil concentration after six months of incubation. P. tuber-regium increased organic matter, carbon and available potassium 5.19%, 2.99% and 0.97 meq/100 g respectively compared to 4.41%, 2.56% carbon and 0.66 meq/100 g, respectively in the control. However, higher values of 0.32% nitrogen, 11.42 ppm phosphorus and pH 6.94 were obtained in the control compared to 0.16% nitrogen, 9.32 ppm phosphorus and pH 5.93 in soils incubated with the fungus. The fungus brought about an increase in copper content in engine oil polluted soils at 10% concentration followed by a decrease at 20 and 40% concentrations. Bioaccumulation of zinc and nickel was recorded at 20% engine-oil concentrations.

Key words: Bioremediation, engine-oil polluted soil, nutrient contents, heavy metals, white-rot fungi.