Resistance genes and extracellular proteins relieve antibiotic stress on the anammox process
Resistance genes and extracellular proteins relieve antibiotic stress on the anammox process
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DOI：
10.1016/j.watres.2021.117453
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发表时间：
2021-07-25
期刊：
影响因子：
12.8
通讯作者：
Zheng, Ping
中科院分区：
文献类型：
--
作者：
Fan, Nian-Si;Fu, Jin-Jin;Zheng, Ping
厌氧氨氧化（anammox）工艺被认为是处理含抗生素废水的一种有前途的方法。因此，迫切需要阐明各种抗生素对厌氧氨氧化过程的影响。此外，细胞外聚合物（EPS）作为缓解抗生素应激的保护屏障的机制仍不清楚。因此，本研究研究了红霉素（ETC）和磺胺甲恶唑（SMZ）的单独作用和联合作用，以及EPS和抗生素之间的相互作用。 228天的连续流实验表明，高浓度的ETC和SMZ对厌氧氨氧化工艺的脱氮性能有显着的抑制作用，相应的抗生素抗性基因（ARG）丰度增加。此外，两种抗生素联合使用对厌氧氨氧化过程的抑制作用比单独使用更显着、更持久。然而，厌氧氨氧化过程能够迅速从恶化中恢复过来。厌氧氨氧化颗粒对低浓度抗生素胁迫的耐受性可能归因于ARGs的增加和EPS的分泌。分子对接模拟结果表明，EPS中的蛋白可分别在GLU307、HYS-191、ASP-318和THR-32位点直接与SMZ和ETC结合。这些发现提高了我们对各种抗生素对厌氧氨氧化过程的影响以及抗生素与 EPS 中蛋白质之间相互作用机制的理解。
The anaerobic ammonium oxidation (anammox) process is regarded as a promising approach to treat antibioticcontaining wastewater. Therefore, it is urgent to elucidate the effects of various antibiotics on the anammox process. Moreover, the mechanism of extracellular polymeric substance (EPS) as protective barriers to relieve antibiotic stress remain unclear. Therefore, the single and combined effects of erythromycin (ETC) and sulfamethoxazole (SMZ), and interactions between EPS and antibiotics were investigated in this study. Based on a 228-day continuous flow experiment, high concentrations of ETC and SMZ had significant inhibitory effects on the nitrogen removal performance of the anammox process, with the abundances of corresponding antibiotic resistance genes (ARGs) increasing. In addition, the combined inhibitory effect of the two antibiotics on the anammox process was more significant and longer-lasting than that of the single. However, the anammox process was able to quickly recover from deterioration. The tolerance of anammox granules to the stress of lowconcentration antibiotics was probably attributed to the increase in ARGs and secretion of EPS. Molecular docking simulation results showed that proteins in EPS could directly bind with SMZ and ETC at the sites of GLU307, HYS-191, ASP-318 and THR-32, respectively. These findings improved our understanding of various antibiotic effects on the anammox process and the interaction mechanism between antibiotics and proteins in EPS.