State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province, 210023, China.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province, 210023, China.
Chemosphere. 2018 Apr;196:206-213. doi: 10.1016/j.chemosphere.2017.12.173. Epub 2017 Dec 28.
Tetrabromobisphenol A (TBBPA) is one of the most widely used brominated flame retardants in the world but it is also a pollutant of global concern. In the present study, we studied the transformation of C-labeled TBBPA by a polychlorinated-biphenyl-degrading bacterium, Rhodococcus jostii RHA1 (RHA1), under oxic conditions. During the 5-day incubation, TBBPA was biotransformed rapidly first to its monomethyl ether MeO-TBBPA and then to its more hydrophobic but less toxic dimethyl ether diMeO-TBBPA. The biotransformation followed pseudo-first-order decay kinetics, with a half-life of TBBPA of 0.32 days and only 0.6% of the initially added amount being mineralized. Considering the frequent co-occurrence of TBBPA with heavy metals in the natural environment, we also investigated the effects of three heavy metals (Cd, Cu, and Fe) on the transformation of TBBPA by strain RHA1. While TBBPA transformation was not significantly altered by Cd, it was accelerated by Cu and Fe, presumably due to the effects of these two essential metals on O-methyltransferase activity. Overall, the present study showed that RHA1 is an effective transformer of TBBPA and that certain essential metals, including Cu and Fe, promote the transformation.
四溴双酚 A（TBBPA）是世界上应用最广泛的溴化阻燃剂之一，但也是一种全球性关注的污染物。在本研究中，我们研究了多氯联苯降解菌 Rhodococcus jostii RHA1（RHA1）在好氧条件下对 C 标记的 TBBPA 的转化。在 5 天的孵育过程中，TBBPA 首先迅速转化为其单甲基醚 MeO-TBBPA，然后转化为疏水性更强但毒性更小的二甲基醚 diMeO-TBBPA。生物转化遵循拟一级衰减动力学，TBBPA 的半衰期为 0.32 天，只有 0.6%的初始添加量被矿化。考虑到 TBBPA 在自然环境中经常与重金属共存，我们还研究了三种重金属（Cd、Cu 和 Fe）对 RHA1 菌株转化 TBBPA 的影响。虽然 Cd 对 TBBPA 的转化没有明显影响，但 Cu 和 Fe 加速了 TBBPA 的转化，这可能是由于这两种必需金属对 O-甲基转移酶活性的影响。总的来说，本研究表明 RHA1 是 TBBPA 的有效转化菌，某些必需金属，包括 Cu 和 Fe，促进了转化。
