摘要
随着抗生素在长江流域的广泛使用,抗生素污染日渐加剧.抗生素的普遍存在可能对生态系统带来危害,环境选择压力对流域环境微生物的群落结构和功能具有潜在影响.本研究选择磺胺甲恶唑(SMX)为典型抗生素,以崇明岛东滩沉积物为研究对象,通过不同浓度水平抗生素长期(60 d)暴露的模拟实验,结合高通量测序与同位素示踪技术,探究了不同温度下抗生素暴露对河口水体和沉积物中微生物群落结构和氮转化过程的影响机制.潜在的氮转化速率定量测试结果表明,SMX在0.5~5μg·L^(-1)的浓度范围内,对河口沉积物中氮转化过程有显著影响,SMX的长期暴露(30~45 d)会显著抑制反硝化和厌氧氨氧化(anammox)过程;进一步延长暴露时间(60 d),SMX的抑制效果减弱.此外,低温(15℃)下反硝化和anammox对SMX的负响应更显著;同等浓度SMX暴露条件下,低温组中(15℃)SMX暴露组与对照组潜在的反硝化/anammox速率差比高温组(25℃)高14%~18%/2%~10%.30 d时,SMX暴露组沉积物中特有物种数量比对照组高17%;线性混合模型结果显示,温度对变形菌门影响更加明显,而SMX则对绿弯菌门有显著负效应.本研究有助于厘清痕量抗生素长期暴露对长江河口地区氮转化的影响机制,并为流域抗生素控制提供技术支撑.
With the widespread use of antibiotics in the Yangtze River Basin,antibiotic pollution is becoming increasingly severe.The pervasive presence of antibiotics may pose risks to ecosystems.Additionally,environmental selection pressures can potentially impact the community structure and functions of microorganisms in the river basin.This study conducted a long-term(60 d)sulfamethoxazole(SMX)exposure simulation experiment at different SMX concentration levels and different temperatures with the sediments of Dongtan on Chongming Island.Combining high-throughput sequencing with isotope tracing techniques,the mechanisms by which antibiotic exposure affects the microbial community structure and nitrogen transformation processes in estuarine waters and sediments under different temperatures were investigated.Quantitative determination of nitrogen transformation rates showed that SMX,within a concentration range of 0.5~5μg·L^(-1),significantly affected nitrogen transformation processes in estuarine sediments.Long-term exposure to SMX(30~45 d)significantly inhibited denitrification and anaerobic ammonia oxidation(anammox)processes.Extending the exposure to 60 days,SMX′s inhibitory effects diminished.Furthermore,at lower temperatures(15℃),the negative responses to SMX exposure for the denitrification and anaerobic ammonia oxidation(anammox)processes were more significant.Under the same concentration of SMX exposure,the potential denitrification/anammox rates difference between the SMX exposure samples at low-temperature group(15℃)with the control group was 14%~18%/2%~10%more that at the high-temperature group(25℃).After 30 days,the sediment of the SMX-exposed group contained 17%more unique species than that in the control group.A linear mixed model revealed that temperature impacted the abundance of Proteobacteria more significantly than other phylum,whereas SMX exerted a notable negative effect on Chloroflexi.This study helped to clarify the mechanisms by which trace antibiotics influence nitrogen transformation in
作者
徐赫姝
郭加汛
张伟航
关傲梅
陈宇枫
陈飞
胡红修
吴涵
黄适尔
齐维晓
李艳红
XU Heshu;GUO Jiaxun;ZHANG Weihang;GUAN Aomei;CHEN Yufeng;CHEN Fei;HU Hongxiu;WU Han;HUANG Shier;QI Weixiao;LI Yanhong(School of Environmental Science and Engineering,Guilin University of Technology,Guilin 541004;Center for Water and Ecology,School of Environment,Tsinghua University,Beijing 100084;Key Laboratory of Drinking Water Science and Technology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085;Yangtze River Ecological Environmental Research Center,China Three Gorges Corporation,Beijing 100038)
出处
《环境科学学报》
CAS
CSCD
北大核心
2024年第12期49-59,共11页
Acta Scientiae Circumstantiae
基金
国家自然科学基金项目(No.52300244,52222004)
中国长江三峡集团有限公司科研项目(No.201903139)。
关键词
长江口
磺胺甲恶唑
高通量测序
氮转化
Yangtze River estuary
sulfamethoxazole
high-throughput sequencing
nitrogen transformation
