Department of Civil and Environmental Engineering, Duke University, Hudson Hall, Durham, NC 27708, USA.
Nicholas School of the Environment, Duke University, 9 Circuit Drive, Durham, NC 27710, USA.
Sci Total Environ. 2019 Mar 15;656:959-968. doi: 10.1016/j.scitotenv.2018.11.403. Epub 2018 Nov 27.
The detection of increasing concentrations of tetrabromobisphenol A (TBBPA) in wastewater treatment plants is raising concerns as TBBPA has been identified as a potentially toxic flame retardant. The objectives of this study were to evaluate the effect of acetate biostimulation on TBBPA microbial reductive debromination, and the response of anaerobic sludge associated microbial communities repeatedly exposed to TBBPA. Results indicate that the bulk of the microbial community did not experience significant shifts as a result of TBBPA exposure, and that only a small fraction of the community responded to the presence of TBBPA. Taxa most likely responsible for TBBPA transformation affiliated to Clostridiales and the wastewater sludge group Blvii28. The biostimulating effect of acetate was only observed during reactor startup, when acetogenesis was likely not yet occurring. However, when acetate likely started to be microbially generated in the reactor, acetate addition resulted in a slight but significant inhibiting effect on TBBPA transformation. A significant increase of hydrogenotrophic methanogens in the TBBPA-spiked reactor overtime implies that TBBPA degraders were not in direct competition with methanogens for H. These results strongly suggest that TBBPA degrading taxa might have been primarily using acetate as an electron donor for the reductive debromination of TBBPA.
检测到越来越多的四溴双酚 A（TBBPA）在废水处理厂，因为 TBBPA 已被确定为一种潜在的有毒阻燃剂，这引起了人们的关注。本研究的目的是评估乙酸生物刺激对 TBBPA 微生物还原脱溴的影响，以及反复暴露于 TBBPA 的厌氧污泥相关微生物群落的反应。结果表明，由于 TBBPA 的暴露，大部分微生物群落没有发生显著变化，只有一小部分群落对 TBBPA 的存在有反应。最有可能负责 TBBPA 转化的分类群与梭菌目和废水污泥组 Blvii28 有关。只有在反应器启动时才观察到乙酸的生物刺激作用，此时很可能还没有发生乙酰生成。然而，当乙酸可能开始在反应器中微生物生成时，乙酸的添加对 TBBPA 的转化产生了轻微但显著的抑制作用。TBBPA 加标反应器中氢营养型产甲烷菌的显著增加意味着 TBBPA 降解菌与产甲烷菌之间没有直接竞争 H。这些结果强烈表明，TBBPA 降解类群可能主要将乙酸用作 TBBPA 还原脱溴的电子供体。
