垃圾堆周边土壤微塑料及潜在病原微生物特征

Characteristics of microplastics and potential pathogenic microorganisms in the soil surrounding a rural garbage dump

为探究农村非正规垃圾堆放点周边土壤的微塑料污染和潜在病原危害,以贵州某典型农村非正规垃圾堆为研究对象,利用宏基因组学技术手段分析包括病毒、病原菌的土壤微生物群落及功能变化,并探究土壤微塑料分布特征及其对微生物的潜在影响.结果表明:垃圾堆放周边土壤均检测出微塑料,丰度为1796~13702个/kg;微塑料包含聚丙烯(PP)、硅树脂、聚氨酯(PU)等20种,以≤100μm粒径为主(占比88.55%).土壤微生物群落分属214门、1336科.土壤病毒以长尾噬菌体科和短尾噬菌体科为主;潜在病原菌共191种.LefSe差异分析表明:β-变形菌、γ-变形菌是近距离区域的指示菌,远距离区域是α-变形菌.虹彩病毒、潘多拉病毒是近距离区域的生物标志物.相关性分析结果表明,垃圾污染土壤中的微塑料影响着微生物的群落组成及病原体的聚集,微塑料各类型中PET对微生物的群落和代谢功能影响最为显著.

To explore the microplastic pollution and potential pathogen risk in the surrounding soil caused by rural garbage stacking,the soil samples around a typical rural garbage dump in Guizhou province were collected for analysis.The microbial community and functional changes in soil,including viruses and pathogens,were studied by metagenomic technology.Combined with the distribution characteristics of microplastics,the potential interaction between microorganisms and microplastics was explored.The results showed that microplastics were detected in all soil samples with the abundance ranging from 1796~13702/kg.A total of 20 kinds of microplastics were detected,including polypropylene(PP),silicone resin and polyurethane(PU),etc.The microplastics particle size were mainly≤100μm with a proportion of 88.55%.The soil microbial community belonged to 214 phyla,and 1336 families,of which Proteobacteria was the dominant phyla.The main soil viruses were Siphoviridae and Podoviridae.A total of 191 potential soil pathogens have been found,including Salmonella enterica,Pseudomonas aeruginosa,Xanthomonas oryzae,etc.LefSe analysis showed thatβ-proteobacteria andγ-proteobacteria were the indicator bacteria in the proximal area,whileα-proteobacteria were key bacteria in the distant area.Iridovirus and Pandoravirus were the biomarkers of the proximal region.The results of correlation analysis showed that microplastics in the garbage contaminated soil might affect the composition of microbial community and the aggregation of pathogens,while PET had the most significant effect on microbial community and metabolic function.