Biodegradation of PAHs by Ligninolytic Fungi Hypoxylon Fragiforme and Coniophora Puteana
ABSTRACT White-rot and brown-rot fungi degrade structural components of wood. The possibility of PAHs degradation by these fungi is based on their structural similarity with lignin (primary degraded by white-rot fungus) and hemi-cellulose and cellulose (degraded by brown-rot fungus). This study compares biodegradation level of polycyclic aromatic hydrocarbons (PAHs) using the two ligninolytic fungi Hypoxylon fragiforme (HF) and Coniophora puteana (CP). The biodegradation of ten PAHs was performed in liquid media (2% w/v in water, of malt extract and 0.5% w/v in water, solution of glucose). After 3 weeks of incubation, non-degraded pollutants were extracted by benzene and determined using the GC/MS technique. Both fungi completely degraded 1-methylnaphthalene and 2-methynaphthalene. 1-methylfluorene was also completely degraded by HF while about 62.7% of it was degraded by CP. The remaining PAHs were degraded by HF and CP fungi, respectively, in the following percentages: 82.0 and 79.0 for acenaphthene; 90.3 and 80.0 for acenaphthylene; 17.8 and 41.3 for anthracene; 5.8 and 53.8 for 1,2-benzanthracene; 0.0 and 20.3 for benzo(k)fluoranthene; 50.5 and 15.8 for byphenil; 85.8 and 74.8 for fluorene; 65.5 and 47.5 for phenanthrene; 42.5 and 50.5 for pyrene.