木贼定居对铅锌尾矿砂微生物多样性及重金属迁移转化的影响

为研究根际微生物影响木贼耐受和吸附重金属的机制,为重金属污染植物-微生物协同修复提供参考,应用化学分析方法和Illumina MiSeq高通量测序技术,对木贼定居对铅锌尾矿重金属含量、土壤微生物多样性的影响进行研究。结果表明,子囊菌、未明确分类真菌和担子菌是铅锌尾矿地土壤的优势真菌。木贼定居导致散囊菌纲、座囊菌纲丰度下降,粪壳菌纲丰度增加。Alternaria,Amorphotheca,Aspergillus为尾矿裸地中主要优势真菌,Fusarium,Chaetomiaceae-Unclassified,Calcarisporiella为木贼根际土壤主要优势真菌。变形菌门、厚壁菌门、放线菌门是研究区土壤中的优势细菌类群,Lactococcus,Bacillus,Gemmatimonas,Sulfuricaulis,Dongia,Sulfurifustis,Azoarcus,Nitrospira等是尾矿地优势细菌。有机质、全氮与真菌和细菌ace,shannon指数显著相关,重金属含量与真菌和细菌ace,shannon指数显著或极显著负相关。木贼定居提高了尾矿砂中微生物的种类和多样性,有利于有机和氮素营养成分的积累和降低重金属含量;在尾矿生态修复实践中可多引入木贼等乡土草本先锋植物,同时补充有机质和氮素营养,或引入功能微生物菌剂和接种植物共生菌等,强化生态修复效果。

The aim of this study is to investigate the mechanism of rhizosphere microorganisms affecting the tolerance and adsorption of heavy metals by Equisetum hyemale L.,and to provide reference for phyto-microbial coremediation of heavy metal pollution.Chemical analysis and high-throughput sequencing technology of Illumina Miseq were used to the effect of settlement of E.hyemale on heavy metal content and soil microbial diversity in lead-zinc tailings.The results showed,ascomycetes,unclassified fungi and basidiomycetes were the dominant fungi in the soil of lead-zinc tailings.The colonization of E.hyemale resulted in the decrease of the abundance of Dothideomycetes and Eurotiomycetes,and the increase of the abundance of Sordariomycetes.Alternaria,Amorphotheca and Aspergillus were the main dominant fungi in the tailings bare land,Fusarium,Chaetomiaceae-Unclassified,Calrisporiella were the main dominant fungi in the rhizosphere soil of E.hyemale.Proteobacteria,Firmicutes and Actinobacteria were the dominant bacteria at phylum level.Lactococcus,Bacillus,Gemmatimonas,Sulfuricauli,Dongia,Sulfurifustis,Azoarcus and Nitrospira were the dominant bacteria at genus level.Organic matter and total nitrogen were significantly correlated with ACE and Shannon index of fungi and bacteria,while heavy metal content was significantly or extremely significantly negatively correlated with ACE and Shannon index of fungi and bacteria.The settlement of E.hyemale increased the species and diversity of microorganisms in tailing sand,which was beneficial to the accumulation of organic and nitrogen nutrients and the reduction of heavy metal content.In the practice of tailing ecological restoration,more pioneer plants such as E.hyemale can be introduced,organic matter and nitrogen nutrition can be supplemented at same time,or functional microbial agents and inoculate plant symbionts can be introduced to strengthen the effect of ecological restoration.