微塑料短期暴露后附着细菌与所在水域环境样本细菌群落及功能差异  

Difference in community structure and function of bacteria attached to microplastics surface after short-term exposure compared to bacteria in the overlying water and sediment

作　　者：袁强 陆依雯 李墨涵 魏雨清 宋海涯 周晓红 许小红 YUAN Qiang;LU Yiwen;LI Mohan;WEI Yuqing;SONG Haiya;ZHOU Xiaohong;XU Xiaohong(School of Environmental and Safety Engineering,Jiangsu University,Zhenjiang,212013,China;School of the Emergency Management,Jiangsu University,Zhenjiang,212013,China)

机构地区：[1]江苏大学环境与安全工程学院,镇江212013 [2]江苏大学应急管理学院,镇江212013

出　　处：《环境化学》2024年第11期3629-3641,共13页Environmental Chemistry

基　　金：国家自然科学基金(31971472);西藏自治区重点研发计划(XZ202301ZY0002N);大学生创新训练计划项目(202210299034Z)资助.

摘　　要：作为新兴环境污染物,微塑料已成为全球广泛关注的热点环境问题.然而,微塑料附着微生物与所在水域环境介质中微生物群落及其功能的对比性研究仍不足.基于此,以我国淡水湖泊高频检出的聚乙烯(PE)、聚氯乙烯(PVC)、聚丙烯(PP)、聚苯乙烯(PS)和聚对苯二甲酸乙二醇酯(PET)微塑料为研究对象,将其于湖泊水体短期暴露42 d后,对比分析微塑料附着细菌与所在水域环境样本(上覆水和沉积物)细菌群落及功能的差异.结果表明,微塑料与所在水域上覆水和沉积物3种来源样本共检测操作分类单元(OTUs)5142个,包含细菌60门164纲377目598科1081属2088种;沉积物以及微塑料附着细菌群落丰富度和物种多样性均显著高于上覆水中浮游细菌(P<0.05);基于层级聚类以及非度量多维尺度分析(NMDS),发现微塑料、沉积物以及上覆水浮游细菌各自形成独特的群落结构.10.44%的细菌同时存在于上覆水、沉积物以及微塑料,而微塑料、上覆水以及沉积物中分别检测到40.95%、1.89%和10.63%的独有OTUs.从门、纲、属分类水平上均发现,微塑料在湖泊中短期暴露将对细菌群落中占比较小的物种产生更显著的影响.PICRUSt2功能预测发现5个KEGG一级代谢通路以及33个二级代谢通路相对丰度在微塑料、上覆水以及沉积物样本间存在显著差异(P<0.05);基于FAPROTAX的生态功能预测结果,发现共有35个功能类群在3种来源样本中存在显著差异(P<0.05),这些差异性的功能类群涉及到碳、氮和硫的生物化学循环;相对于环境样本,微塑料附着细菌具有更高的硝酸盐还原、氮呼吸和硝酸呼吸功能;而沉积物具有更高的固氮作用、亚硝酸盐脱氮、氧化亚氮脱氮、硝酸盐反硝化以及反硝化作用.以上结果证实了微塑料的存在对所在水域细菌群落结构和功能均产生影响.微塑料附着细菌与附着物理化参数间存在一定的相关性.本文所选5种�Microplastics,an emerging environmental pollutant,has emerged as a hot environmental issue and has been widely concerned around the world.However,the difference in community structure and function between bacteria attached to microplastics surface and bacteria in the overlying water and sediment is still lacking.Hence,the microplastic particles of polyethylene(PE),polyvinyl chloride(PVC),polypropylene(PP),polystyrene(PS)and polyethylene terephthalate(PET)detected by high frequency in freshwater lakes in China were taken as the research objects and placed in the lake for short-term exposure for 42 days.The differences of bacterial communities and functions between the bacteria attached to the surface of microplastics and the water samples(overlying water and sediment)were compared and analyzed.The results showed that a total of 5142 OTUs were detected in the microplastics samples,the overlying water samples,and the sediment samples.These OTUs include 60 phyla,164 classes,377 orders,598 families,and 1081 genera.The community richness and species diversity of bacteria attached to the surface of sediments and microplastics were significantly higher than that of plankton bacteria in overlying water(P<0.05).Complex and unique community structures were observed in microplastic surface,sediment and overlying water,respectively,based on hierarchical clustering and non-metric multidimensional scaling analysis(NMDS).10.44%of common OTUs were detected both from on the surface of microplastics,the overlying water,sediment and microplastics,while 40.95%,1.89%and 10.63%of unique OTUs were just detected from microplastics,overlying water and sediment samples,respectively.In terms of phyla,class and genus classification,it was found that microplastics surface after short-term exposure in lakes would have a more significant impact on species with low relative abundance.PICRUSt2 function prediction showed that the relative abundance of 6 primary metabolic pathways and 33 secondary metabolic pathways of KEGG were significantly diffe

关 键 词：微塑料 细菌群落 功能预测 沉积物 上覆水 

分 类 号：X-1[环境科学与工程] O6[理学—化学]