Biodegradation of Pyrene by Pleurotus ostreatus HP-1 and its Correlation with Extracellular Ligninolytic Enzyme Production

A basidiomycete fungal isolate Pleurotus ostreatus HP-1 (GenBank Accession no. EU420068) was obtained by successive transfer from rotted wood sample, collected from forest locality in Gujarat, India. The biodegradation of four ring polycyclic aromatic hydrocarbon (PAH), pyrene was studied in submerged cultures of these fungi. Maximum degradation of 38.21% was observed on 10^th day of incubation period after addition of pyrene to 6 days grown culture. There after no significant level of degradation was observed. Biodegradation was confirmed by high pressure liquid chromatography (HPLC) and attempt was done to detect the extracellular degradation product in the degradation medium by high pressure thin layer chromatography (HPTLC), liquid chromatography-mass spectroscopy (LC-MS), fourier transforminfrared (FT-IR) and ¹³C nuclear magnetic resonance (NMR) spectroscopy. Liquid chromatography-mass spectroscopy revealed that pyrene was transformed in to some other higher molecular weight compound; till date such transformation is not reported for fungal degradation of pyrene. The PAH biodegradation potential of the basidiomycetes fungi positive ely correlated with their potential to produce the ligninolytic enzymes and fungal biomass.