The Role of Aspergillus parasiticus NRRL:3386 Strain on Petroleum Biodegradation and Biosorption Processes

Objective: Fungi play an important role in the removal of hazardous organic compounds from the environment with their extracellular multiple enzyme systems. In the bioremediation processes, fungi act as a bioreactor by breaking down or are biosorbent by accumulating organic pollutants. Materials and Methods: The aim of this study was to investigate and to compare the biodegradation and biosorption capacities of different amounts of live and dead biomasses and different concentrations of culture supernatants of Aspergillus parasiticus NRRL:3386 with gravimetric, gas chromatography-mass spectrometry (GC/MS) and scanning electron microscope analyses (SEM). Results: This study indicated that 1 g of live biomass degraded 80% of petroleum within 4-days of incubation. The cell-free culture supernatant was not as effective as the live biomass in petroleum degradation. The petroleum biosorption was achieved at over 50% by 1 g and 2.5 g; over 70% by 5 g and 7.5 g, and over 80% by 10 g of dead biomasses. The petroleum removal efficiencies of 2 g of live and 10 g of dead biomasses were over 80%. GC/MS analysis demonstrated that C10 - C18 n-alkanes (except C11 and C13) and C11, C13, C19 - C26 n-alkanes were degraded 47 - 77% and over 80%, respectively. The most striking result was that C27 - C33 n-alkanes were efficiently degraded over 90% in a short incubation period. It was clearly shown by SEM analysis that the gaps between fungal hyphae were clear and bright before biosorption of petroleum, whereas the gaps between fungal hyphae were closed after biosorption of petroleum. Conclusion: The results clearly pointed out that A. parasiticus NRRL:3386 will make a significant contribution to advanced mycoremediation studies.