Degradation of 4-Fluorobiphenyl by Mycorrhizal Fungi as Determined by 19F Nuclear Magnetic Resonance Spectroscopy and 14C Radiolabelling Analysis

The pathways of biotransformation of 4-fluorobiphenyl (4FBP) by the ectomycorrhizal fungus Tylospora fibrilosa and several other mycorrhizal fungi were investigated by using 19F nuclear magnetic resonance (NMR) spectroscopy in combination with 14C radioisotope-detected high-performance liquid chromatography (14C-HPLC). Under the conditions used in this study T. fibrillosa and some other species degraded 4FBP. 14C-HPLC profiles indicated that there were four major biotransformation products, whereas 19F NMR showed that there were six major fluorine-containing products. We confirmed that 4-fluorobiphen-4′-ol and 4-fluorobiphen-3′-ol were two of the major products formed, but no other products were conclusively identified. There was no evidence for the expected biotransformation pathway (namely, meta cleavage of the less halogenated ring), as none of the expected products of this route were found. To the best of our knowledge, this is the first report describing intermediates formed during mycorrhizal degradation of halogenated biphenyls.