College of Environmental Science and Engineering, Hunan University, Changsha, 410082, People's Republic of China.
Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, People's Republic of China.
Environ Sci Pollut Res Int. 2022 Sep;29(42):63379-63392. doi: 10.1007/s11356-022-18841-8. Epub 2022 Apr 22.
Per- and polyfluoroalkyl substances (PFASs) have received increasing attention due to their widespread presence in diverse environments including wastewater treatment plants (WWTPs) and their potential adverse health effects. Perfluorooctanoic acid (PFOA) is one of the most detected forms of PFASs in WWTPs. However, there is still a paucity of knowledge about the effect of PFASs on microorganisms of the key component of WWTP, activated sludge. In this study, lab-scale microcosm experiments were established to evaluate the influences of PFOA on activated sludge microbes under aerobic and anaerobic conditions. The diversity, structure, and microbe-microbe interaction of microbial community were determined by 16S rRNA gene amplicon sequencing and co-occurrence network analysis. After 90 days of exposure to PFOA, activated sludge microbial richness decreased under both aerobic and anaerobic conditions. Specifically, under aerobic condition, Rhodopseudomonas (mean relative abundance 3.6%), Flavobacterium (2.4%), and Ignavibacterium (6.6%) were enriched in PFOA-spiked activated sludge compared with that in the unspiked sludge (2.6%, 0.1%, and 1.9%, respectively). By contrast, after 90 days of exposure to PFOA, Eubacterium (2.1%), Hyphomicrobium (1.8%), and Methyloversatilis (1.2%) were enriched under anaerobic condition, and more abundant than that in the control sludge (0.4%, 1.5%, and 0.6%, respectively). These genera were the potential PFOA-resistant members. In addition, Azospirillum and Sporomusa were the most connected taxa in PFOA-aerobic and PFOA-anaerobic networks, respectively. Prediction of the functional gene showed that PFOA inhibited some gene expression of sludge microbes, such as transcription, amino acid transport and metabolism, and energy production and conversion. In summary, continued exposure to PFOA induced substantial shifts of the sludge bacterial diversity and composition under both aerobic and anaerobic conditions.
由于其在各种环境（包括污水处理厂 (WWTP)）中的广泛存在及其潜在的不良健康影响，全氟和多氟烷基物质 (PFASs) 受到了越来越多的关注。全氟辛酸 (PFOA) 是 WWTP 中检测到的 PFASs 最常见的形式之一。然而，对于 PFASs 对 WWTP 关键组成部分——活性污泥中的微生物的影响，人们的了解仍然很少。在这项研究中，建立了实验室规模的微宇宙实验，以评估有氧和厌氧条件下 PFOA 对活性污泥微生物的影响。通过 16S rRNA 基因扩增子测序和共生网络分析，确定了微生物群落的多样性、结构和微生物-微生物相互作用。在接触 PFOA 90 天后，有氧和厌氧条件下，活性污泥微生物的丰富度均降低。具体而言，在有氧条件下，与未加 PFOA 的污泥相比，加 PFOA 的污泥中 Rhodopseudomonas（平均相对丰度 3.6%）、Flavobacterium（2.4%）和 Ignavibacterium（6.6%）得到了富集，而未加 PFOA 的污泥中 Rhodopseudomonas（平均相对丰度 2.6%）、Flavobacterium（0.1%）和 Ignavibacterium（1.9%）。相比之下，在接触 PFOA 90 天后，在厌氧条件下，Eubacterium（2.1%）、Hyphomicrobium（1.8%）和 Methyloversatilis（1.2%）得到了富集，且丰度高于对照污泥（0.4%、1.5%和 0.6%）。这些属是潜在的 PFOA 抗性成员。此外，在 PFOA 有氧和 PFOA 厌氧网络中，Azospirillum 和 Sporomusa 分别是最具连接性的分类群。功能基因预测表明，PFOA 抑制了污泥微生物的一些基因表达，如转录、氨基酸运输和代谢以及能量产生和转化。总之，在有氧和厌氧条件下，持续接触 PFOA 会导致污泥细菌多样性和组成发生显著变化。
