【摘要】 微塑料和抗生素抗性基因都是环境中的新兴污染物,也是近年来的研究热点.为探究微塑料对河口沉积物抗生素抗性基因的影响,在沉积物中添加3种不同的微塑料进行培养实验,主要采用高通量定量PCR方法研究河口沉积物抗性基因种类、丰度、多样性及其变化情况.结果表明,微塑料显著改变了沉积物中抗生素抗性基因结构组成,两种难降解微塑料PVC和PE使得沉积物抗生素抗性基因组成结构显著改变,而可溶性微塑料PVA使得沉积物抗生素抗性基因种类数显著减少;添加PVC、PE和PVA微塑料的沉积物抗生素抗性基因的绝对丰度显著增加,分别为4. 1×10⁹、8. 1×10⁹和2. 0×10⁹copies·g^-1,添加PE微塑料的沉积物抗生素抗性基因丰度增加了近一个数量级,微塑料显著增加了沉积物抗生素抗性基因的绝对丰度; OLS回归分析显示,抗生素抗性基因丰度与转座子、整合子基因显著正相关,表明可移动遗传元件可能促进了抗生素抗性基因的迁移、传播和扩散.更多还原

【Abstract】 Microplastics and antibiotic resistance genes（ ARGs） are emerging pollutants/contaminants,and are also the research hotspots concerning environmental health in the past few years. To explore the effects of microplastics on ARGs in estuarine sediment,three different microplastics were added to microcosm incubation experiments of sediments. Then,we investigated the persistence,abundance,diversity,and shifts of the ARGs in estuarine sediments by high-throughput quantitative polymerase chain reaction（ PCR）. The results showed that the microplastics significantly changed the structure of ARGs in the sediments. PVC and PE,which are hard to degrade,had significant effects on the structures and types of ARGs. However,the PVA,which is soluble,reduced the types and persistence of ARGs significantly. The abundance of ARGs in S_PVC,S_PE,and S_PVA were 4. 1 × 10⁹,8. 1 × 10⁹,and2. 0 × 10⁹ copies·g^-1,respectively. The abundance of ARGs in sediments with added PE almost increased by one order of magnitude,implying that microplastics could significantly increase the abundance of ARGs in sediments. Furthermore,OLS regression analysis showed that ARGs are significantly correlated with transposon and integron,suggesting that mobile genetic elements（ MGEs） may promote the transfer and dissemination of ARGs.更多还原