摘要
      本研究评估了复合抗生素胁迫（50–200μg/L四环素（TC）、磺胺嘧啶（SD）和环丙沙星（CIP））对脱氮过程从全硝化向短程硝化反硝化（SCND）传递的长期影响，重点研究了污染物去除性能、抗生素抗性基因（ARGs）和细菌群落。结果表明，由于功能性细菌群落的富集，复合抗生素可以促进从完全硝化到SCND的过程，其中总氮的去除率提高了51.24%–60.36%。在整个过程中，抗生素类型与ARG亚型之间的对应关系不是一一对应的。与完全硝化相比，SCND中ARGs/MGEs的增加率和总环境风险逐渐降低，表明即使在4倍抗生素的胁迫下，SCND也具有更强的稳定性。SCND中的主要功能反硝化属（Brachymonas）远高于全硝化中的反硝化属，但未被确定为TC、SD和CIP的潜在宿主。网络分析和偏最小二乘路径模型（PLS-PM）进一步证实了ARG/MGE可以通过调节环境因素来控制。这项研究深入了解了复合抗生素对SCND的影响，并指导了未来在废水处理中控制抗生素和ARGs污染的努力。
Abstract
The long-term effects of compound antibiotics stress (50–200 μg/L tetracycline (TC), sulfadiazine (SD) and ciprofloxacin (CIP)) on the transmission of nitrogen removal process from full nitrification to shortcut nitrification and denitrification (SCND) were evaluated in this study, with the focus on pollutants removal performance, antibiotic resistance genes (ARGs) and bacterial community. Results showed that compound antibiotics could promote the process from full nitrification to SCND due to the enrichment of functional bacterial community, in which the removal rates of total nitrogen increased by 51.24%–60.36%. In the whole process, the correspondence between antibiotic types and ARG subtypes was not one-to-one. Compared with full nitrification, the increase rates of ARGs/MGEs and the total environmental risks in SCND were gradually decreased, indicating SCND had a stronger stability even stress on 4 times antibiotics. The main functional denitrifying genera (Brachymonas) in SCND were far higher than that in full nitrification, but it was not identified as potential hosts of TC, SD and CIP. The Network analysis and Partial least-squares path model (PLS-PM) further confirmed that ARGs/MGEs could be controlled by regulating environmental factors. This study provides an insight into the effects of compound antibiotics on SCND, and guides future efforts to control antibiotic and ARGs pollution in wastewater treatment.

https://www.sciencedirect.com/science/article/abs/pii/S1385894722042310