微塑料及金属在黄浦江地表水环境的赋存特征及与金属抗性基因的相关性分析  

Occurrence Characteristics of Microplastics and Metal Elements in the Surface Water of Huangpu River and Their Associations with Metal Resistance Genes

作　　者：陆嘉玮 徐晨烨 胡纯 刘树仁 李方[1] LU Jia-wei;XU Chen-ye;HU Chun;LIU Shu-ren;LI Fang(College of Environmental Science and Engineering,Donghua University,Shanghai 201620,China;College of Environment and Resources,Zhejiang University,Hangzhou 310058,China)

机构地区：[1]东华大学环境科学与工程学院,上海201620 [2]浙江大学环境与资源学院,杭州310058

出　　处：《环境科学》2023年第5期2551-2561,共11页Environmental Science

基　　金：国家自然科学基金项目(22006010)。

摘　　要：城市河流是微塑料(MPs)及重金属污染的“热点”区域,在污染迁移中起到重要作用.然而同样作为抗性基因赋存及释放的重要媒介,鲜有研究考察了流域MPs、金属与金属抗性基因(MRGs)的关联.为此,调研了10个黄浦江站点水样的金属及MPs的污染特征,并基于宏基因组学对水样及提取的MPs上的MRGs及可移动遗传元件(MGEs)进行分析.结果显示,表层水中ρ[锑(Sb)]平均值最高,为(3.16±0.419)μg·L^(-1).MPs的丰度平均值为(1.78±0.84)n·L^(-1),位于工业区和人口密集区的MPs丰度显著高于农业区和低人口密度的区域.纤维状、“小粒径”(<0.5 mm)的聚对苯二甲酸乙二醇酯(PET)是最主要的MPs类型.所有样本中共检出18类MRGs,其中水样中MRGs的相对丰度为1.68±0.21.最主要的MRGs亚型是merR和ruvB,分别为汞和多重金属抗性基因的亚型.相关性分析表明,水中的铬和镍与MRG-Cr、MRG-Ni和多重金属抗性基因之间存在显著正相关.MPs上MRGs的相对丰度为1.63±0.53,最主要的MRGs亚型是merT-P和copB,同样为汞和多重金属抗性基因的亚型.其中多重金属抗性基因亚型ctpC、cueA、czrA和kmtR等与水中的Ni、Cr和Sb含量都存在显著正相关.与水样相比,MPs选择性富集merT-P、copB、ziaA、sodA和dmeF.此外,基于网络分析挖掘了MRGs和MGEs的共现模式.在水环境中,MRGs可经由转座子tnpA_1和tnpA_2,整合子qacEdelta及插入序列IS91实现水平基因转移,使微生物产生对应金属的抗性.MPs表面多重金属抗性基因和铜的抗性基因与质粒的亚型IncFIC(FII)、Rep7、rep7和rep13之间存在显著正相关,MPs的存在对由质粒介导的特定MRGs的水平基因转移有着显著影响.Urban rivers have been regarded as the"hotspots"for microplastic(MPs)and metal contamination as they play important roles in pollution migration.However,as important sinks and sources of resistance genes,there has been little to no research investigating the associations between MPs,metal contaminations,and metal resistance genes(MRGs).Ten water samples were collected from the Huangpu River in situ;along with metal elements,MPs characteristics analyzed.Metal resistance genes and mobile genetic elements(MGEs)in waters and MPs were detected using metagenomic technology.As a result,the highest metal concentration was that of Sb in surface water(3.16±0.419)μg·L^(-1).The average abundance of MPs was(1.78±0.84)n·L^(-1),and the peak levels located in industrial and densely populated areas,which was significantly higher than those in agricultural and low population density areas.Fibrous,small-size(<0.5 mm),and transparent polyethylene terephthalate(PET)were the largest contributors of MPs.Eighteen MRGs were detected in all the samples.The relative abundance of MRGs in water was 1.68±0.21.The most dominant MRGs subtypes were merR and ruvB,which are subtypes resistant to mercury and Multi_metals.Correlation analysis showed that chromium and nickel in waters were significantly positively associated with MRG-Cr,MRG-Ni,and Multi_metals resistance genes.For MPs particles,the relative abundance of MRGs was 1.63±0.53.The most dominant MRGs subtypes were merT-P and copB,which also belong to mercury-resistant and Multi_metals.The Multi_metals resistance gene,ctpC,cueA,czrA,kmtR,etc.,had significant positive associations with Ni,Cr,and Sb in waters.Compared with water samples,MPs selectively enriched merT-P,copB,ziaA,sodA,and dmeF.Additionally,the co-occurrence patterns of MRGs and MGEs were explored based on network analysis.In water samples,the transposases(tnpA_1 and tnpA_2),integrase(qacEdelta),and insertion sequence(IS91)were the major contributors of the horizontal gene transfer(HGT)of specific MRGs.Multiple subtypes r

关 键 词：微塑料(MPs) 金属 金属抗性基因(MRGs) 可移动遗传元件(MGEs) 宏基因组学 

分 类 号：X171.5[环境科学与工程—环境科学]