Characteristics and mechanism of aerobic biodegradation of tetrabromobisphenol A by Irpex lacteus F17

Abstract:

[Objective] To research the possibilities of biodegradation of brominated flame retardants by Irpex lacteus F17, we studied the characteristics and influence factors of aerobic degradation of tetrabromobisphenol A (TBBPA), and the degradation pathway was speculated based on the analysis of intermediates.[Methods] We determined the concentration of TBBPA during biodegradation by high-performance liquid chromatography (HPLC), and detected the intermediate products by gas chromatography-mass spectrometry (GC-MS).[Results] TBBPA could be biodegraded by I. lacteus F17 via co-metabolism, and glucose was confirmed to be the most appropriate co-metabolic matrix. Under the optimal degradation conditions which were 8 g/L glucose, 5% inoculum volume, pH 5.0, the degradation rate and the debromination rate were 85.5% and 14.6%, respectively, for 20 mg/L TBBPA. It was found that the degradation rate of TBBPA was related to the activity of manganese peroxidase (MnP). On the basis of GC-MS analysis, we detected seven intermediate products.[Conclusion]] I. lacteus F17 could degrade TBBPA effectively, and debromination, β-scission, hydroxylation, deprotonation, and oxidation were involved in the degradation mechanism of TBBPA by Irpex lacteus F17.