典型兽用抗生素胁迫下厌氧氨氧化系统中的质粒组特征及抗性基因转移机制

厌氧氨氧化（anammox）技术在高氨氮的畜禽养殖废水脱氮处理方面具有广阔的应用前景。然而，畜禽养殖废水中的抗生素对anammox菌的活性存在抑制作用。现有研究主要围绕抗生素对anammox工艺的抑制进行，并未系统地阐明低浓度抗生素胁迫下anammox系统的抗性发展及抗性基因的转移机制。本项目拟选用畜禽养殖废水中的典型兽用抗生素磺胺二甲嘧啶为研究对象，从脱氮效能、微生物种群结构及功能基因等角度，揭示磺胺二甲嘧啶对anammox系统的影响及其抑制浓度。利用高通量测序技术，进一步探究在低于抑制浓度的抗生素压力下anammox系统中的质粒多样性及抗性质粒组特征。结合对抗性细菌的全基因组测序分析，深入解析携带抗性基因的插入序列及质粒的结构特征，并阐明磺胺类抗性基因的转移机制。本项目的实施将有助于深入了解废水生物处理系统中抗生素抗性基因的来源与归趋，同时为畜禽养殖废水脱氮新技术的发展提供理论指导。

Anaerobic ammonia oxidation (anammox) technology has a broad application prospect in the treatment of livestock wastewater with high ammonia nitrogen. Nevertheless, antibiotics in livestock wastewater significantly affect the activity of anammox bacteria. The present researches mainly focus on the inhibition of antibiotics on anammox process, but have not systematically elucidated the resistance development of anammox system and the transfer mechanism of resistance genes under low-concentration antibiotics stress. This project will select sulfadimidine, a typical antibiotic in livestock wastewater, as the research target. The effect and inhibitory concentration of sulfadimidine on anammox system will be revealed from the perspectives of nitrogen removal performance, microbial community structure and functional genes. Furthermore, high-throughput sequencing technology will be applied to explore the plasmid diversity and the characteristics of resistant plasmidome in anammox system under the antibiotics stress with lower concentrations. Combined with the whole-genome sequencing analysis on the antibiotic resistance bacteria (ARB) in the system, the structural features of the inserted sequences and plasmids that carrying antibiotic resistance genes (ARGs) will be further analyzed, and the transfer mechanism of sulfonamides ARGs will also be clarified. This project will contribute to the in-depth understanding of the source and fate of ARGs in wastewater biological treatment systems, and provide a theoretical guidance for the development of new nitrogen removal technologies for livestock wastewater.