Abstract

Aim

Biodegradation is a cost-effective and eco-friendly treatment for oil-contaminated materials using microorganisms. Bacteria and fungi can degrade petroleum by using it as an energy source and this may provide an enormous scope to remediate soils contaminated with petroleum and oil. This study aimed to assess the biodegradation of petroleum hydrocarbons by certain Cladosporium species.

Methods and results

By using traditional and spectroscopic assessment analysis, qualitative screening was carried out using Cladosporium spores isolated from air and cultured on mineral salt medium supplemented with petroleum hydrocarbon as the sole carbon source, followed by quantitative assessment using gas chromatography–mass spectroscopy. Nineteen Cladosporium strains from a total of 212 isolates exhibited remarkable capability to degrade petroleum hydrocarbon, representing four species (C. herbarum, C. macrocarpum, C. sphaerospermum, and C. cladosporioides). The results were expressed in terms of biodegradation percentage and optical density of hydrocarbon using a standard calibration curve. The highest reduction of petroleum hydrocarbon was observed with five Cladosporium strains belonging to two species (C. sphaerospermum and C. cladosporioides).

Conclusion

This study succeeded in isolating several Cladosporium strains (from the air) with a high ability to degrade crude oil that can be used as biological agents to control petroleum pollution in soils and seas. The addition of a surfactant (Tween 80) enhanced the degradation of crude oil reaching a final concentration of 0.4%. Based on these results, the present study could indicate some unique prospects in the field of bioremediation and biodegradation of petroleum-contaminated soil.

Significance and impact of study

This study gives unique prospects in the field of bioremediation and biodegradation of petroleum-contaminated soil.