High salinity is a common feature of industrial wastewater, however, little is known about the impact of salinity on antibiotic resistance genes (ARGs) and overall bacteria communities in saline wastewater treatment processes. In this study, three reactors were operated for 120 days under different salinities to investigate the dynamics of ARGs and microbial communities. The results showed that the nitrogen removal efficiency of the reactors decreased from 85% to 20% when the salinity was increased from zero to 4%, while 95% organic matter removal could still be achieved at 4% salinity. Interestingly, it was found that the relative abundance of ARGs (especially sul2, tetG and amrB) dropped by almost 50% in the reactor added with sodium chloride. Correlation analysis showed that some bacterial operational taxonomic units were highly associated with the ARGs during wastewater treatment processes in the reactors, suggesting that high salinity may inhibit the growth of some bacteria carrying ARGs and may be used as a potential approach for ARG reduction in the wastewater treatment systems.

高盐度是工业废水的常见特征，但是，盐碱对盐水处理过程中抗生素抗性基因（ARG）和整个细菌群落的影响知之甚少。在这项研究中，三个反应器在不同盐度下运行了120天，以研究ARG和微生物群落的动态。结果表明，当盐度从零增加到4％时，反应器的脱氮效率从85％降低到20％，而在盐度为4％时仍然可以达到95％的有机物去除率。有趣的是，发现在添加氯化钠的反应器中，ARG的相对丰度（尤其是sul2，tetG和amrB）下降了近50％。