State Key Laboratory of Organic Geochemistry, Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Wushan, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China.
State Key Laboratory of Organic Geochemistry, Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Wushan, Guangzhou 510640, China.
Environ Pollut. 2019 Dec;255(Pt 2):113151. doi: 10.1016/j.envpol.2019.113151. Epub 2019 Sep 12.
Severe contamination of decabrominated diphenyl ether (BDE-209, an emerging persistent organic pollutant) in coastal marine sediments has posed a serious threat to the marine ecosystems. Anaerobic microbial degradation can affect the toxicity and environmental fate of BDE-209 in anoxic marine sediments. However, little is known about the anaerobic microbial degradation of BDE-209 in anoxic marine/coastal sediments. In this study, the anaerobic degradation of BDE-209 in microcosms containing coastal marine sediments from a contaminated bay located in Southern China was investigated. It was observed that over 70% of the BDE-209 (5 μmol) added to the anaerobic sediment microcosms disappeared after 90-day of incubation. Thirty-five debrominated products (tetra- to nonaBDEs) were identified by GC-MS. Remarkably, a majority of these products (i.e. 20 products, including BDE-52, -92, -101, -102, -103, -133, -144, -146, -150, -161, -171, -172, -175, -177, -178, -180, -182, -188, -193, -199) have not been previously reported in the literature on the anaerobic microbial degradation of BDE-209 in sediments. There was no preferential debromination among ortho-, meta-, and para-bromines on BDE-209 and higher-brominated diphenyl ethers were the predominant debromination products. High-throughput sequencing revealed that the relative abundances of 9 microbial genera in the sediment microcosms increased as the anaerobic degradation of BDE-209 progressed, indicating their involvements in the degradation process. Taken together, our findings provided new insights into the anaerobic microbial degradation of BDE-209 in anoxic marine sediments.
十溴二苯醚（BDE-209，一种新兴的持久性有机污染物）在沿海海洋沉积物中的严重污染对海洋生态系统构成了严重威胁。在缺氧海洋沉积物中，厌氧微生物降解会影响 BDE-209 的毒性和环境归宿。然而，对于缺氧海洋/沿海沉积物中 BDE-209 的厌氧微生物降解知之甚少。在这项研究中，研究了来自中国南方受污染海湾的沿海海洋沉积物微宇宙中 BDE-209 的厌氧降解。观察到添加到厌氧沉积物微宇宙中的 5µmol BDE-209 在 90 天的孵育后消失了 70%以上。通过 GC-MS 鉴定出 35 种脱溴产物（四溴至九溴二苯醚）。值得注意的是，这些产物中的大多数（即 20 种产物，包括 BDE-52、-92、-101、-102、-103、-133、-144、-146、-150、-161、-171、-172、-175、-177、-178、-180、-182、-188、-193、-199）以前在文献中未曾报道过 BDE-209 在沉积物中的厌氧微生物降解。BDE-209 上的邻位、间位和对位溴原子之间没有优先脱溴，并且高溴代二苯醚是主要的脱溴产物。高通量测序显示，随着 BDE-209 的厌氧降解，沉积物微宇宙中 9 种微生物属的相对丰度增加，表明它们参与了降解过程。综上所述，我们的研究结果为缺氧海洋沉积物中 BDE-209 的厌氧微生物降解提供了新的见解。
