Key fungal degradation patterns, enzymes and their applications for the removal of aliphatic hydrocarbons in polluted soils: A review

Many saturated or unsaturated aliphatic hydrocarbons in fuels and their derivate pose considerable hazards to biological receptors due to the formation of toxic and carcinogenic metabolites. Currently, “bioremediation” (the use of living organisms to mitigate environmental pollution) is gaining public attention due to its cost-effectiveness and environment-friendly strategies. Understanding of biodegradation mechanisms is of high ecological significance; it relies on the use of indigenous microorganisms to transform/mineralize hydrocarbon contaminants. Fungal degradation processes have been well proven to degrade many hydrocarbons as they possess different cassettes of enzymes which enable them to degrade and utilize different hydrocarbons as sole carbon/energy sources. However, there is still a dearth of knowledge on fungal abilities for degradation of aliphatic hydrocarbons with respect to aromatics. The present paper is a review of the main results published on the ability of fungi in degrading aliphatic hydrocarbons. Aliphatics have been considered in particular for their abundance in the crude oil mixture and its derivate. The paper focuses on the biochemical processes and mechanisms involved in the degradation, analysing the differences observed in micromycetes (mainly Ascomycota) and macromycetes (Basidiomycota). The application of fungi in bioremediation in field-scale experiences is also discussed in light of environmental constraints