English
Screening and Identification of Diesel Degrading Fungi from the Marine Environment
Heewon Park, Ji Seon Kim, and Young Woon Lim*
School of Biological Sciences and Institute of Biodiversity, Seoul National University, Seoul, Republic of Korea
Email: ywlim@snu.ac.kr
Fungi play an important role in the degradation of recalcitrant compounds and are increasingly recognized as key agents in oil bioremediation. While oil-degrading capabilities of terrestrial fungi have been extensively studied, research on marine-derived fungi remains limited, despite their potential to address frequent coastal oil pollution. In this study, we aimed to identify potential diesel-degrading fungi by isolating candidates from tidal flat sediments and seawater collected from an oil-polluted coastal area near Incheon Port and quantitatively assessing their degradation capacity. Using a dilution-to-extinction method, we obtained 217 fungal isolates that were either tolerant to diesel or capable of utilizing diesel as a carbon source. Among these isolates, 24 strains exhibited relatively strong degradation activity, as determined by diesel degradation screening using 2,6-dichlorophenol indophenol (DCPIP), a redox indicator that changes color based on its oxidation state. Through multi-locus phylogenetic analysis, these 24 strains were identified as 20 taxa across 10 genera. A quantitative diesel-degradation assay revealed that 18 of these strains exhibited significantly higher degradation capacity than the abiotic control (Welch’s t-test, p < 0.05). Notably, several species of Aspergillus, Geotrichum, and Penicillium exhibited the highest diesel degradation capacities among the tested strains. This study enhances the basic understanding of the saprotrophic ecological role of fungi in marine environments, particularly regarding their oil-degrading capabilities, and will serve as an important foundation for developing fungal bioremediation strategies in the marine environment.
