International Science and Technology Journal

This study aims to isolate and characterize fungi from soil contaminated with petroleum hydrocarbons, test the efficiency of the isolated fungi in decomposing hydrocarbons, and them the possibility of using as bio remedies at different concentrations of crude oil. A number of fungal isolates were obtained from soil samples contaminated with oil and its derivatives and cultured on Potato Dextrose Agar. The results showed a clear growth of: Aspergillus Fumigatus, Aspergillus Clavatus, Aspergillus Terreus, Aspergillus Oryzae, Penicillum Sp1, Penicillum Sp2. Then their efficiency in decomposing hydrocarbons was tested in two ways, first by measuring the growth diameters in a solid medium of potato dextrose agar added to different concentrations of crude oil (1%, 3%, 5%) v/v. Secondly, measuring the percentage of consumption by gravimetric analysis in a liquid medium of potatoes and dextrose added to different concentrations of crude oil (1%, 3%, 5%) v/v. The growth diameter of Aspergillus Clavatus was the highest in all crude oil concentrations with an average diameter of (5.7, 3, 4.25cm) for the three concentrations, respectively, while Aspergillus Terreus was the smallest growth diameter among the other four strains, with an average of (2.48, 2.56, 2.44cm), respectively. Aspergillus Fumigatus achieved the highest consumption rates (84.58, 78.7, 70.2%) for concentrations of 1, 3, 5% respectively, while Penicillum Sp2 achieved the lowest consumption rates (76.08, 62.09, 61%) for concentrations of 1, 3, 5% respectively. These results indicate the possibility of using the isolated fungi in the biological treatment of soil contaminated with oil and its derivatives. Aspergillus Fumigatus and Aspergillus Clavatus are among the most efficient fungi isolated in decomposition...................... Keywords: ...........crude oil - decomposition efficiency - contaminated soil - fungi