高通量测序揭示某石化固废填埋场污染对土壤微生物群落结构和功能的影响

石油化工行业产生大量固体废物，包含有毒有害污染物，其填埋处置可能对周边环境造成潜在危害，亟待开展石化固废填埋场对周边环境的影响研究．本文选择中国北方某石化固废填埋场作为研究对象，采用16S rDNA和宏基因组高通量测序技术揭示填埋场土壤微生物群落结构和功能特征，评估其对周边土壤微生物的影响．研究结果表明:填埋场土壤微生物群落结构较背景点存在差异，属水平上，Solirubrobacter等丰度降低；Mycobacterium、Sphingomanas、Arthrobacter和Bradyrhizobium等丰度增加；同时其微生物群落功能也区别于背景点，直系同源蛋白簇（COG）注释到高丰度的生物学功能，不仅有助于维持微生物正常的生理活动，也可帮助其适应外源污染胁迫；与背景点相比，填埋场土壤差异表达的基因功能与微生物对于污染胁迫的降解反应及毒性响应相关．填埋场构筑的防渗墙以及低渗透性介质条件能够有效地降低填埋场污染对于周边土壤微生物群落结构和功能的影响．相关性分析证实污染胁迫，特别是多环芳烃污染胁迫，是填埋场土壤微生物群落结构和功能改变的重要原因． 

Influence of pollutants on soil microbial community structure and function at a petrochemical landfill site: a high-throughput sequencing study

The petrochemical industry produces a large amount of solid wastes, including toxic and harmful pollutants．Landfill disposal of such wastes may cause potential harm to surrounding environment．Thus, it is urgent to study environmental influence of pollutants at petrochemical landfill site．In this work, 16S rDNA and metagenomics were examined to study soil microbial community structure and functions at a typical landfill site in northern China．Soil microbial community structure was found shifted when compared with a normal background site．At the genus level, abundance of Solirubrobacter was found decreased, abundance of Mycobacterium, Sphingomanas, Arthrobacter and Bradyrhizobium increased．Functions of soil microbial community at this landfill site showed marked differences from a control background site．High-abundance biological functions, as annotated by Cluster of Orthologous Groups of proteins (COG), were found involved in both maintaining normal physiological activities of microorganisms and adapting to exogenous pollution stress．Compared with the background site, differentially expressed genes at landfill site were found, mainly related to microbial degradation and toxicity response to pollution stress．Constructed impermeable system and low permeability medium conditions could effectively lessen impacts of landfill on microbial community structure and functions in the surrounding soil．Correlation analysis confirmed that pollution stresses, especially polycyclic aromatic hydrocarbons pollution stress, were an important factor causing alterations in soil microbial community structure and function ．