Effects of sulfamethoxazole on the denitrifying process in anoxic activated sludge and the responses of denitrifying microorganisms
Effects of sulfamethoxazole on the denitrifying process in anoxic activated sludge and the responses of denitrifying microorganisms
复制标题
磺胺甲恶唑对缺氧活性污泥反硝化过程的影响及反硝化微生物的反应
DOI：
10.2166/wst.2018.394
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发表时间：
2018-09-01
影响因子：
2.7
通讯作者：
Qin, Xueming
中科院分区：
文献类型：
--
作者：
An, Yonglei;Qin, Xueming
城市污水中抗生素的存在必然会影响缺氧活性污泥（AAS）的缺氧脱氮过程。本文研究了磺胺甲恶唑（SMZ）对原子吸收光谱法中微生物分解过程的影响及微生物的响应。结果表明，当SMZ浓度低于10 mg/L时，会显著降低硝酸盐的去除速率，当SMZ浓度高于100 mg/L时，硝酸盐的去除完全受到抑制。弱碱性条件会增强SMZ对缺氧生物反应器中硝酸盐去除的抑制作用。高通量测序和qPCR（定量聚合酶链反应）结果表明，100 mg/L的SMZ不会降低微生物的总丰度。然而，经100 mg/L SMZ处理的AAS中关键反硝化基因NirS和NosZ的相对表达水平与不含SMZ的原始AAS相比仅为0.030和0.036。因此，SMZ对AAS发酵过程的抑制机制可能是通过有效抑制发酵基因的表达，而不是通过降低发酵微生物的总丰度。
The presence of antibiotics in municipal wastewater is bound to affect the anoxic denitrifying process in anoxic activated sludge (AAS). This study investigated the effects of sulfamethoxazole (SMZ) on the denitrifying process in AAS and the responses of denitrifying microorganisms. The results showed that SMZ could decrease the speed of nitrate removal significantly when the concentration of SMZ was lower than 10 mg/L, and the removal of nitrate would be completely inhibited when SMZ concentration was higher than 100 mg/L. Weak alkaline condition would enhance the inhibition effect of SMZ on removal of nitrate in the anoxic bioreactor. The results of high-throughput sequencing and qPCR (quantitative polymerase chain reaction) showed that 100 mg/L of SMZ did not decrease the total abundance of denitrifying microorganisms. However, the relative expression levels of key denitrifying genes NirS and NosZ in AAS treated by 100 mg/L of SMZ versus the raw AAS without SMZ was only 0.030 and 0.036. Therefore, the inhibitory mechanism of SMZ on the denitrifying process in AAS was denoted by an effective inhibition to the expressions of denitrifying genes, rather than a decrease in the total abundance of denitrifying microorganisms.