摘要
活性污泥是细胞外耐药基因(eARGs)重要储存库之一,本文采用宏基因组技术探究了不同温度(12,20和30℃)饥饿胁迫(即无营养基质)下活性污泥中eARGs的动态特征.结果表明,30d饥饿促使eARGs的相对与绝对丰度分别削减3.5%~26.0%、66.1%~81.4%,且eARGs的丰度在12℃饥饿后明显高于20和30℃饥饿.12℃饥饿能够维持大部分胞外可移动遗传元件(eMGEs)的稳定性,而20和30℃饥饿导致eMGEs的相对丰度分别降低41.4%~54.4%、48.7%~67.4%.eARGs优势寄主(Mycobacterium和Nitrospira)的丰度在不同温度饥饿后保持稳定.与20和30℃饥饿相比,12℃饥饿下活细胞比例较高,且胞外DNA吸附/降解率较低,有利于维持eARGs的稳定性.研究结果阐明了不同温度饥饿胁迫对活性污泥中eARGs归趋的影响,可为控制实际污水处理厂中eARGs的散播提供科学依据.
Activated sludge is a vital reservoir for extracellular antibiotic resistance genes(eARGs).The metagenomic sequencing technology was used for the first time to examine the impacts of starvation(i.e.,substrate deficiency)at different temperatures(12℃,20℃and 30℃)on the dynamic of eARGs in activated sludge.The results indicated that the abundance of eARGs after 30-days starvation was effectively reduced by 3.5%~26.0%,66.1%~81.4%,respectively.The abundance of eARGs after 12℃starvation was higher than that after 20℃and 30℃starvation.The majority of extracellular mobile genetic elements changed little after starvation at 12℃,but their abundance after 12℃and 30℃starvation decreased by 41.4%~54.4%,48.7%~67.4%,respectively.The relative abundance of the dominated hosts of eARGs(i.e.,Mycobacterium and Nitrospira)remained stable after starvation at different temperatures.The kinetic studies confirmed that,compared with 20℃and 30℃starvation,12℃starvation had higher proportion of living cells and relatively lower adsorption or degradation rate of extracellular DNA,which was conducive to maintain the stability of eARGs.The present study was helpful for elucidating the fate of eARGs in activated sludge in response to starvation stress at different temperatures,which could provide a scientific basis for controlling the propagation and dissemination of eARGs in actual wastewater treatment plants.
作者
唐振平
刘博阳
高媛媛
段毅
杨正卿
周帅
TANG Zhen-ping;LIU Bo-yang;GAO Yuan-yuan;DUAN Yi;YANG Zheng-qing;ZHOU Shuai(Hunan Province Key Laboratory of Pollution Control and Resources Reuse Technology,University of South China,Hengyang 421001,China;Hunan Province Key Laboratory of Rare Metal Mineral Exploitation and Geological Disposal of Wastes,University of South China,Hengyang 421001,China;School of Civil Engineering,University of South China,Hengyang 421001,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2023年第3期1397-1406,共10页
China Environmental Science
基金
国家自然科学基金资助项目(52100219)
湖南省教育厅项目(21A0288)
污染控制与资源化研究国家重点实验室开放课题资助项目(PCRRF21001)
南华大学研究生科研创新项目(223YXC016)。
关键词
活性污泥
细胞外耐药基因(eARGs)
饥饿
温度
宏基因组
动力学
activated sludge
extracellular antibiotic resistance genes(eARGs)
starvation
temperature
metagenomics
kinetics
