الفهرس | Only 14 pages are availabe for public view |
Abstract Biodegradation of polycyclic aromatic hydrocarbons (PAHs), (naphthalene, anthracene, 1, 10 phenanthroline) by white rot fungus Pleurotus ostreatus in a salt solution (SS) media, as a sole carbon and energy source was time dependent. The decrease in PAHs coincided with the increase in fungal biomass. Multifactorial design for optimization of naphthalene biodegradation showed that higher levels of malt extract, glucose and CuSO4 as well as lower levels of EDTA and CdSO4 resulted in maximum degradation. UV-spectrophotometry, HPLC and thin layer chromatographic analysis of the biodegradation products at different time intervals proposed that naphthalene was first degraded to Ü and Ý naphthol which was further metabolized to salicylic and benzoic acid. Participation of lignolytic enzymes of Pleurotus ostreatus in the degradation process was established, genes coding for 6 laccase isomers were detected using PCR. The transcriptome of these genes showed that the variation in their levels was dependent on the fermentation conditions and was significantly elevated in presence of naphthalene and Tween 80. Higher levels of transcription of lignolytic enzymes were also observed at optimized fermentation conditions. Our results pointed out that biodegradation of PAHs proceeded via lignolytic pathway. The metabolic pathway of naphthalene degradation by this fungus was to the best of our knowledge elucidated for the first time. The accumulation of useful metabolites (Ü and Ý naphthol, salicylic and benzoic acid) from the biodegradation of PAHs pollutants proposes white rot fungus as a potential candidate for production of platform chemicals from PAHs wastes |