摘要
      海水废水具有高浓度土霉素（OTC）和盐的特点，这对传统的生物脱氮工艺来说是一个巨大的挑战。海洋厌氧氨氧化菌（MAB）由于其良好的耐盐性，最近被用于从含盐废水中去除氮。本研究首次重点研究了OTC对MAB去除海水废水中氮的影响，特别强调了抗生素抗性基因（ARG）的增殖和群体感应（QS）反应。在低OTC剂量（≤7 mg L−1）下，MAB具有良好的耐受性，总氮去除率保持在77%。当OTC剂量达到22 mg L−1时，MAB的活性受到明显抑制。当OTC剂量从0 mg L−1增加到22时，MAB的相对丰度从14.41%急剧下降到4.1%。相反，随着OTC含量的增加，抗生素耐药性细菌逐渐成为反应器中的优势种群，同时伴随着ARGs相对丰度的增加。ARGs的高表达增强了基于MAB的联合体对OTC毒性的耐受性。此外，分泌更多的细胞外聚合物物质来增强厌氧氨氧化颗粒对OTC毒性的耐受性，这是由信号分子（3OC6-HSL）的高释放所促进的。此外，QS调节hdh和tetM的表达，以增强OTC应激下基于MAB的联合体耐受性。因此，厌氧氨氧化联合体对OTC的耐受性主要归因于ARGs的增殖和活性QS。这项工作开发了MAB在海水废水处理中的巨大潜力。
Abstract
Seawater-based wastewater is characterized by high concentrations of oxytetracycline (OTC) and salt, which is a huge challenge for conventional biological nitrogen removal processes. Marine anammox bacteria (MAB) are recently employed for nitrogen removal from saline wastewater due to their good salt tolerance. This study focuses on the impacts of OTC on MAB for nitrogen removal from seawater-based wastewater for the first time, particularly highlighting the antibiotic resistance gene (ARG) proliferation and quorum sensing (QS) response. At low OTC doses (≤7 mg L−1), MAB had a good tolerance and the total nitrogen removal efficiency was maintained at 77%. When OTC dose reached 22 mg L−1, the activity of MAB was inhibited obviously. The relative abundance of MAB drastically decreased to 4.1% from 14.41% when OTC dose increased to 22 from 0 mg L−1. On contrary, antibiotic resistance bacteria gradually became the dominant population in reactor with increasing OTC content, accompanying along with the increase of relative abundance of ARGs. The tolerance of MAB-based consortia to OTC toxicity was enhanced by the high expression of ARGs. Besides, more extracellular polymeric substance was secreted to enhance anammox granule tolerance against OTC toxicity, which was promoted by the high release of signal molecule (3OC6-HSL). Furthermore, the expression of hdh and tetM was regulated by QS to enhance MAB-based consortia tolerance under OTC stress. Therefore, the tolerance of anammox consortia to OTC was mainly attributed to proliferated ARGs and active QS. This work exploited the significant potential of MAB in seawater-based wastewater treatment.

https://www.sciencedirect.com/science/article/abs/pii/S1385894722030273