Abstract：
The long-term effects of oxytetracycline (OTC) with a high concentration on the anaerobic ammonium oxidation (Anammox) process were evaluated, and the role of static magnetic field (SMF) was further explored. The stress of OTC at 50 mg/L had little effect on the nitrogen removal of anammox process at the first 16 days. With the continuous addition of OTC and the increase of nitrogen loading, the OTC inhibited the nitrogen removal and anammox activity severely. During the 32 days of recovery period without OTC addition, the nitrogen removal was further deteriorated, indicating the inhibition of OTC on anammox activity was irreversible and persistent. The application of SMF alleviated the inhibition of OTC on anammox to some extent, and the specific anammox activity was enhanced by 47.1% compared to the system without SMF during the OTC stress stage. Antibiotic efflux was the major resistance mechanism in the anammox process, and tetA, tetG and rpsJ were the main functional antibiotic resistance genes. The addition of OTC weakened the metabolic interactions between the anammox bacteria and the symbiotic bacteria involved in the metabolism of cofactors and secondary metabolites, leading to the poor anammox activity. The adaptability of microbes to the OTC stress was improved by the application of SMF, which can enhance the metabolic pathways related to bacterial growth and resistance to environmental stress.
摘要：
评估了高浓度土霉素（OTC）对厌氧氨氧化（Anammox）过程的长期影响，并进一步探讨了静磁场(SMF)的作用。50mg/L的OTC胁迫在前16天对厌氧氨氧化过程的脱氮效果影响不大。随着OTC的不断添加和氮气负荷的增加,OTC严重抑制了脱氮和厌氧氨氧化活性。在没有场外交易的32天恢复期内，氮的去除进一步恶化，表明OTC对anammox活性的抑制作用是不可逆和持久的。SMF的应用在一定程度上减轻了OTC对anammox的抑制作用，在OTC胁迫阶段，与没有SMF的系统相比，比anammox活性提高了47.1％。抗生素外排是厌氧氨氧化过程中的主要耐药机制，还有tetA,tetG和rpsJ是主要的功能性抗生素抗性基因。添加OTC削弱了厌氧氨氧化菌与参与辅因子和次生代谢产物代谢的共生菌之间的代谢相互作用,导致不良的厌氧氨氧化活性。SMF的应用提高了微生物对OTC胁迫的适应性,能增强与细菌生长相关的代谢途径和对环境胁迫的抗性。
