Mycoremediation of Iranian Crude Oil Contaminated Soil by Indigenous Fungi Isolates and the Evaluation of Their Bioremediation Ability

Abstract

Bioremediation is one of the most effective approaches to eliminate or reduce soil contamination. Samples were collected from petroleum-contaminated soil in Oil Refinery Plant in Isfahan, Iran. The soil samples were cultured and the isolates were identified by polymerase chain reaction method. Total petroleum hydrocarbons assessment and measurement of the absorbance at 420 nm were used to determine the capability of fungi for bioremediation of petroleum hydrocarbons. Five isolates of fungi were purified from petroleum-contaminated soils. The oil degrading fungal isolates were identified as Aspergillus niger, Rhodotorula mucilaginosa, Penicillium sp., Penicillium chrysogenum, and Mucor circinelloides. All isolates had mycoremediation activity among which, Aspergillus niger, Mucor circinelloides, and Penicillium sp. had the highest potential to reduce total petroleum hydrocarbons (85%, 64%, and 53%, respectively) during 3 months. In addition, biosurfactant-producing ability was found only in these three isolates. The A. niger isolate had a high ability in hydrocarbons removal and, the P. chrysogenum isolate had significant ability in biosurfactant production, they can be applied in the bioremediation of contaminated soil in microbial consortia. The use of native microorganisms living in contaminated soils, especially fungi, have a high efficiency in removing contaminants of petroleum hydrocarbons in the soil.