摘要
      水产养殖和污水排放等人类活动引起的浅水湖泊中抗生素和重金属残留问题备受关注和公众关注。然而，这些环境污染物影响微生物介导的生物地球化学循环的机制尚不清楚。本研究重点研究了抗生素、重金属和抗生素抗性基因（ARGs）对浅水湖泊反硝化作用的影响。结果表明，抗生素和金属元素对反硝化作用具有抑制作用，而AGRs则具有刺激作用。具体而言，恩诺沙星浓度与反硝化细菌的拷贝数呈显著负相关，而ARGs sulI、sulII和tetG的拷贝数则呈显著正相关。此外，tetG与nirS型反硝化菌的群落结构密切相关，nirS型脱氮菌与潜在脱氮率（PDR）显著相关。此外，ARGs-sulI、sulII和tetG与PDR呈正相关（P<0.05）。相反，金属元素砷、锰、钴和锑与反硝化细菌的拷贝数呈负相关。砷与nirK型反硝化菌的群落组成显著相关，但nirK类型反硝化菌与PDR没有显著相关性。这项工作扩展了我们对抗生素和重金属对反硝化作用的理解，但还需要进一步的研究来确定污染物的相互作用效应。
Abstract
Antibiotic and heavy metal residues in shallow lakes caused by aquaculture and human activities such as sewage discharge have attracted much attention and public concern. However, mechanisms by which these environmental pollutants affect the microorganism-mediated biogeochemical cycle are unknown. This study focused on the effects of antibiotics, heavy metal, and antibiotic resistance genes (ARGs) on denitrification in shallow lakes. The results showed that antibiotics and metal elements had inhibitory effects on denitrification, whereas AGRs exhibited stimulating effects. Specifically, the enrofloxacin concentration showed a significant negative correlation with the copy number of denitrifying bacteria, whereas the copy number of the ARGs sulI, sulII, and tetG showed significant positive correlations. In addition, tetG was closely related to the community structure of nirS-type denitrifiers, and nirS-type denitrifiers were significantly correlated with the potential denitrification rate (PDR). Furthermore, the ARGs sulI, sulII, and tetG were positively correlated with PDR (P < 0.05). By contrast, the metal elements arsenic, manganese, cobalt, and antimony were negatively correlated with the copy number of denitrifying bacteria. Arsenic was significantly correlated with the community composition of nirK-type denitrifiers, but nirK-type denitrifiers did not show a significant correlation with the PDR. This work extends our understanding of the effects of antibiotics and heavy metals on denitrification, but further studies are needed to determine the interaction effects of pollutants.

https://www.sciencedirect.com/science/article/abs/pii/S0045653521034202