Effects of Sulfamethazine on Denitrification and the Associated N2O Release in Estuarine and Coastal Sediments
Effects of Sulfamethazine on Denitrification and the Associated N2O Release in Estuarine and Coastal Sediments
复制标题
磺胺二甲嘧啶对河口和沿海沉积物反硝化及相关 N2O 释放的影响
DOI：
10.1021/es504433r
复制
发表时间：
2015-01-06
影响因子：
11.4
通讯作者：
Tong, Chunfu
中科院分区：
文献类型：
--
作者：
Hou, Lijun;Yin, Guoyu;Tong, Chunfu
反硝化作用是河口和沿海生态系统脱氮和生成氧化亚氮的重要途径，在对抗过量氮负荷引起的水体富营养化中起着重要作用。由于抗生素的生产和使用不断增加，河口和沿海环境也受到越来越多的抗生素污染。本研究通过沉淀液培养实验来确定磺胺乙嗪（SMT，一种磺胺类抗生素）对反硝化和相关N2O产量的影响。对反硝化和抗生素耐药性的重要基因进行了量化，以研究SMT对反硝化作用的微生物生理机制。SMT显著抑制了反硝化速率，但SMT浓度的增加提高了N2O的释放速率。反硝化基因丰度与SMT浓度之间的负指数关系表明，SMT通过限制反硝化细菌的生长来降低反硝化速率，尽管在孵育期间检测到抗生素抗性基因的存在。这些结果表明，在河口和沿海生态系统中广泛存在的残留抗生素可能通过抑制反硝化和刺激N2O释放来影响富营养化控制、温室效应和大气臭氧消耗。
Denitrification is an important pathway of nitrogen removal and nitrous oxide (N2O) production in estuarine and coastal ecosystems, and plays a significant role in counteracting aquatic eutrophication induced by excessive nitrogen loads. Estuarine and coastal environments also suffer from increasing antibiotic contamination because of the growing production and usage of antibiotics. In this study, sediment slurry incubation experiments were conducted to determine the influence of sulfamethazine (SMT, a sulphonamide antibiotic) on denitrification and the associated N2O production. Genes important for denitrification and antibiotic resistance were quantified to investigate the microbial physiological mechanisms underlying SMT's effects on denitrification. SMT was observed to significantly inhibit denitrification rates, but increasing concentrations of SMT enhanced N2O release rates. The negative exponential relationships between denitrifying gene abundances and SMT concentrations showed that SMT reduced denitrification rates by restricting the growth of denitrifying bacteria, although the presence of the antibiotic resistance gene was detected during the incubation period. These results imply that the wide occurrence of residual antibiotics in estuarine and coastal ecosystems may influence eutrophication control, greenhouse effects, and atmospheric ozone depletion by inhibiting denitrification and stimulating the release of N2O.