Zhao Siyan, Fan Siyan, He Yide, Zhang Yongjun
School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, China.
Front Microbiol. 2022 Feb 17;12:806795. doi: 10.3389/fmicb.2021.806795. eCollection 2021.
Polybrominated diphenyl ethers (PBDEs), commonly used as flame retardants in a wide variety of consumer products, are emerging persistent pollutants and ubiquitously distributed in the environment. The lack of proper bacterial populations to detoxify these recalcitrant pollutants, in particular of higher brominated congeners, has confounded the attempts to bioremediate PBDE-contaminated sites. In this study, we report a -containing enrichment culture, PB, which completely debrominates 0.44 μM tetra-brominated diphenyl ether (BDE) 47 to diphenyl ether within 25 days (0.07 μM Br/day) and extensively debrominates 62.4 ± 4.5% of 0.34 μM hepta-BDE 183 (0.006 μM Br/day) with a predominant generation of penta- through tri-BDEs as well as small amounts of diphenyl ether within 120 days. Later, a marked acceleration rate (0.021 μM Br/day) and more extensive debromination (87.7 ± 2.1%) of 0.38 μM hepta-BDE 183 was observed in the presence of 0.44 μM tetra-BDE 47, which is achieved the faster growth rate of responsible bacterial populations on lower BDE-47 and debromination by expressed BDE-47 reductive dehalogenases. Therefore, the PB enrichment culture can serve as a potential candidate for PBDE bioremediation since both BDE-47 and BDE-183 are dominant and representative BDE congeners and often coexist in contaminated sites.
多溴二苯醚（PBDEs）通常用作多种消费品中的阻燃剂，是新出现的持久性污染物，在环境中广泛分布。缺乏合适的细菌种群来解毒这些难降解污染物，尤其是高溴代同系物，这使得对多溴二苯醚污染场地进行生物修复的尝试受到阻碍。在本研究中，我们报告了一种含[具体物质未给出]的富集培养物PB，其在25天内可将0.44μM四溴二苯醚（BDE）47完全脱溴为二苯醚（0.07μM溴/天），并在120天内将0.34μM七溴二苯醚183的62.4±4.5%进行广泛脱溴（0.006μM溴/天），主要生成五溴至三溴二苯醚以及少量二苯醚。之后，在存在0.44μM四溴二苯醚47的情况下，观察到0.38μM七溴二苯醚183的脱溴速率显著加快（0.021μM溴/天）且脱溴更广泛（87.7±2.1%），这是由于负责的细菌种群在较低的BDE - 47上生长速度更快以及表达的BDE - 47还原脱卤酶进行脱溴所致。因此，PB富集培养物可作为多溴二苯醚生物修复的潜在候选物，因为BDE - 47和BDE - 183都是多溴二苯醚的主要且具有代表性的同系物，并且经常共存于污染场地。
