Beijing Engineering Research Center of Environmental Material for Water Purification, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing, 100048, China.
Environ Pollut. 2022 Nov 1;312:120035. doi: 10.1016/j.envpol.2022.120035. Epub 2022 Aug 26.
Chlortetracycline (CTC) has attracted increasing attention due to its potential environmental risks. However, its effects on bacterial communities and microbial interactions in activated sludge systems remain unclear. To verify these issues, a lab-scale sequencing batch reactor (SBR) exposed to different concentrations of CTC (0, 0.05, 0.5, 1 mg/L) was carried out for 106 days. The results showed that the removal efficiencies of COD, TN, and TP were negatively affected, and the system functions could gradually recover at low CTC concentrations (≤0.05 mg/L), but high CTC concentrations (≥0.5 mg/L) caused irreversible damage. CTC significantly altered bacterial diversity and the overall bacterial community structure, and stimulated the emergence of many taxa with antibiotic resistance. Molecular ecological network analysis showed that low concentrations of CTC increased network complexity and enhanced microbial interactions, while high concentrations of CTC had the opposite effect. Sub-networks analysis of dominant phyla (Bacteriodota, Proteobacteria, and Actionobacteriota) and dominant genera (Propioniciclava, a genus from the family Pleomorphomonadaceae and WCHB1-32) also showed the same pattern. In addition, keystone species identified by Z-P analysis had low relative abundance, but they were important in maintaining the stable performance of the system. In summary, low concentrations of CTC enhanced the complexity and stability of the activated sludge system. While high CTC concentrations destabilized the stability of the overall network and then caused effluent water quality deterioration. This study provides insights into our understanding of response in the bacteria community and their network interactions under tetracycline antibiotics in activated sludge system.
金霉素（CTC）因其潜在的环境风险而受到越来越多的关注。然而，其对活性污泥系统中细菌群落和微生物相互作用的影响尚不清楚。为了验证这些问题，进行了一个实验室规模的序批式反应器（SBR）实验，该反应器暴露于不同浓度的 CTC（0、0.05、0.5、1mg/L）中，持续了 106 天。结果表明，COD、TN 和 TP 的去除效率受到负面影响，而在低 CTC 浓度（≤0.05mg/L）下，系统功能可以逐渐恢复，但高 CTC 浓度（≥0.5mg/L）会导致不可逆转的损害。CTC 显著改变了细菌多样性和整体细菌群落结构，并刺激了许多具有抗生素抗性的类群的出现。分子生态网络分析表明，低浓度的 CTC 增加了网络的复杂性并增强了微生物相互作用，而高浓度的 CTC 则产生了相反的效果。对优势门（Bacteriodota、Proteobacteria 和 Actinobacteriota）和优势属（Propioniciclava，一个来自 Pleomorphomonadaceae 科的属和 WCHB1-32）的子网络分析也显示出相同的模式。此外，Z-P 分析确定的关键种相对丰度较低，但它们在维持系统稳定性能方面很重要。综上所述，低浓度的 CTC 增强了活性污泥系统的复杂性和稳定性。而高 CTC 浓度会破坏整个网络的稳定性，从而导致出水水质恶化。本研究为我们在活性污泥系统中理解四环素抗生素下细菌群落的响应及其网络相互作用提供了新的认识。
