Guo Haixiao, Chen Zhi, Lu Caicai, Guo Jianbo, Li Haibo, Song Yuanyuan, Han Yi, Hou Yanan
School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China; Tianjin Key Laboratory of Aquatic Science and Technology, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China.
Department of Building, Civil, and Environmental Engineering, Concordia University, 1455 de Maisonneuve Blvd. W. Montreal, Quebec, Canada.
Bioresour Technol. 2020 Jun;305:123073. doi: 10.1016/j.biortech.2020.123073. Epub 2020 Feb 22.
The environmental risks of the sulfonamide antibiotics have attracted much attention recently. In this study, the inhibition effects of sulfadiazine (SDZ) on denitrification electron transfer system (ETS) and ameliorative mechanisms of phosphomolybdic acid (PMo) were first explored. When denitrification was under 2 mg/L SDZ stress, experiments indicated that PMo enhanced NO-N reduction efficiency and rate from 68.30% to 100.00% and 124.22 to 184.59 N/g VSS/h, respectively. Electron transfer rate and consumption efficiency in denitrification ETS were enhanced to ameliorate SDZ inhibition, which was due to the more secreted riboflavin and cytochrome c and the increased denitrifying enzymes activity with PMo mediation. In addition, the microbial growth inhibition and cell membrane damage were ameliorated due to the more EPS surrounding microbe with PMo mediation. Higher diversity of denitrifying microbe with PMo mediation also promoted denitrification under SDZ stress. This work provided promising strategy to ameliorate antibiotics inhibition in the wastewater bio-treatment.
磺胺类抗生素的环境风险近来备受关注。在本研究中，首次探究了磺胺嘧啶（SDZ）对反硝化电子传递系统（ETS）的抑制作用以及磷钼酸（PMo）的改善机制。当反硝化处于2 mg/L SDZ胁迫下时，实验表明，PMo分别将NO-N的还原效率从68.30%提高到100.00%，还原速率从124.22提高到184.59 N/g VSS/h。反硝化ETS中的电子传递速率和消耗效率得到提高，以减轻SDZ的抑制作用，这是由于在PMo的介导下，分泌了更多的核黄素和细胞色素c，且反硝化酶活性增加。此外，在PMo的介导下，由于微生物周围有更多的胞外聚合物（EPS），微生物生长抑制和细胞膜损伤得到改善。在PMo的介导下，反硝化微生物更高的多样性也促进了SDZ胁迫下的反硝化作用。这项工作为改善废水生物处理中抗生素的抑制作用提供了有前景的策略。
