Co-biomass degradation of fluoranthene by marine-derived fungi; Aspergillus aculeatus and Mucor irregularis: Comprehensive process optimization, enzyme induction and metabolic analyses

Abstract

The application and relevance of marine-derived fungi in the mycoremediation of environment polluted with polycyclic aromatic hydrocarbons (PAHs) is promising whilst limiting environmental hazards. The present study investigated the fluoranthene degradation efficiency of marine-derived fungal co-culture, Aspergillus aculeatus (AA) and Mucor irregularis (MI) in batch processes (Plackett-Burman experiments) enhanced with the addition of surfactants and solid-state substrates. Further optimization studies done through fractional factorial design revealed that the co-culture exhibited 98.4% fluoranthene degradation capacity after 7 days of incubation. The role played by enzymes was revealed with 93, 85 and 71% induction of laccase, lignin peroxidase and manganese peroxidase respectively during fluoranthene degradation. The Gas Chromatography-Mass Spectrometry analysis revealed the formation of five metabolites; 1,2- dihydroxyfluoranthene, 9H-fluorene-1,9-dicarboxylic acid, benzene-1,2,4-tricarboxylic acid, benzene-1,3-dicarboxylic acid and benzoic acid after fluoranthene degradation by AA + MI co-culture which was used in predicting a metabolic pathway. The findings of this study elucidated the promising potentials of marine-derived fungal co-biomass in the eco-friendly remediation of polycyclic aromatic hydrocarbons thus promoting green technology.