Effects of methanol on the performance of a novel BDE-47 degrading bacterial consortium QY2 in the co-metabolism process

2,2′,4,4′-tetrabrominated diphenyl ether (BDE-47), frequently detected in the environment, is arduous to be removed by conventional biological treatments due to its persistence and toxicity. Herein effects of methanol as a co-metabolic substrate on the biodegradation of BDE-47 was systematically studied by a functional bacterial consortium QY2, constructed through long-term and successive acclimation from indigenous microorganisms. The results revealed that BDE-47 (0.25 mg/L) was completely removed within 7 days in the 2.5 mM methanol treatment group, and its degradation efficiency was 3.26 times higher than that without methanol treatment. The addition of methanol dramatically accelerated the debromination, hydroxylation and phenyl ether bond breakage of BDE-47 by QY2. However, excessive methanol (>5 mM) combined with BDE-47 had strong stress on microbial cells, including significant (p