摘要
      抗生素耐药性在水生环境中的快速传播与抗生素耐药性基因（ARGs）的流行密切相关。环境ARG经历一定程度的太阳光解和氯氧化。本报告是首次通过太阳能/游离氯过程全面研究质粒编码的细胞外抗生素抗性基因（pUC19）的太阳能光降解机制。与单独氯化（0.04 min−1）和直接太阳能光解（0.05 min−1。将pH值从6增加到8导致更高的臭氧产量并加速pUC19的光降解。在反应时间的20分钟内，臭氧和羟基自由基（•OH）分别占pUC19降解的37.5%和55.1%，而活性氯物种（RCS）的贡献可以忽略不计。由同一片段中不同扩增子长度确定的降解率显示出与扩增子长度的线性相关性。太阳能/游离氯的攻击可能是非选择性的，因为位于不同pUC19片段（ampR和ori）中的相似扩增子长度显示出相似的降解率。太阳/游离氯过程引起的pUC19损伤是破坏DNA双键的最有效治疗方法。尽管受到水基质成分的干扰和抑制，但在真实的游泳池水中也观察到了增强的太阳能/游离氯光解现象，这为控制受氯水生环境中的ARGs提供了有价值的见解。
Abstract
The rapid spread of antibiotic resistance in aquatic environments is closely related to the prevalence of antibiotic resistance genes (ARGs). Environmental ARGs undergo some degree of solar photolysis and chlorine oxidation. This report is the first study to comprehensively investigate the solar photodegradation mechanism of a plasmid-encoded extracellular antibiotic resistance gene (pUC19) via the solar/free chlorine process. The pUC19 degradation rate via the solar/free chlorine process was significantly enhanced (1.15 ± 0.05 min−1) compared to chlorination (0.04 min−1) and direct solar photolysis (0.05 min−1) alone. Increasing the pH values from 6 to 8 resulted in a higher yield of ozone and accelerated pUC19 photodegradation. Within 20 min of the reaction time, ozone and hydroxyl radicals (•OH) were responsible for 37.5% and 55.1% of the pUC19 degradation, respectively, and the contribution of reactive chlorine species (RCS) was negligible. Degradation rates, determined by different amplicon lengths in the same segment, showed a linear correlation with amplicon length. The attack by solar/free chlorine may be nonselective because similar amplicon lengths located in different pUC19 segments (ampR and ori) showed similar degradation rates. The pUC19 lesions caused by the solar/free chlorine process were the most effective treatment for breaking DNA double bonds. An enhanced solar/free chlorine photolysis phenomenon was also observed in real swimming pool waters, despite interference and inhibition by the water matrix components, which provides valuable insight into the control of ARGs in chlorine-receiving aquatic environments.

https://www.sciencedirect.com/science/article/abs/pii/S2213343721019618