Biodegradation of crude oil through fungi isolated from southern parts of Iran

Background and Aim : Extensive consumption of crude oil and its derivatives (Petroleum) leads to an enormous increase in contaminating the natural environment. Crude oil is a complex mixture containing thousands of hydrocarbon molecules with immunotoxic and carcinogenic impacts. Methods : Here, we isolated the fungal populations associated with the soils contaminated by crude oil from southern regions of Iran to discover promising candidates with a high ability to biodegrade crude oil. Soil samples from surface soil were collected, and fungi were isolated on Potato Dextrose Agar (PDA), Water agar (W), and Malt Extract Agar (MEA) media. Fungal genera were identified based on the morphological characters and classified according to available taxonomic keys. Additionally, the molecular assay is currently ongoing to determine the fungal species. Bushnell-Haas broth medium was applied to corroborate the ability of the isolated fungi to biodegrade the crude oil. To this accomplish, the addressed medium was amended by tween ۸۰ (۰.۱%), redox reagent (۲% ۲, ۶-dichlorophenol indophenols), and crude oil (۱%). Results : Among the ۲۷۰ identified isolates, the main group was Alternaria, representing ۸۱% of isolates and, to a lesser extent, Fusarium, Cladosporium, Rhizoctonia, Trichoderma, Penicillium, Aspergillus, Geotrichum, Epicoccum, and Zygomycetes. Based on the colorimetric assay through redox reagent, isolates possessing the enormously high capacity to degrade the crude oil belonged to Alternaria (۱۳ isolates) and Cladosporium (۵ isolates), which significantly degraded crude oil compared to the control. Conclusion : Our results demonstrated the biodegradation efficiency of some fungal isolates that can be employed as biological agents to eliminate hazardous molecules from the environment.

کلیدواژه ها:

Biodegradation ، Crude oil ، Colorimetric test ، Fungi