School of Chemical and Biological Engineering, School of Environmental and Municipal Engineering, Key Laboratory of Extreme Environmental Microbial Resources and Engineering in Gansu Province, Lanzhou Jiaotong University, Lanzhou 730070, China.
School of Chemical and Biological Engineering, School of Environmental and Municipal Engineering, Key Laboratory of Extreme Environmental Microbial Resources and Engineering in Gansu Province, Lanzhou Jiaotong University, Lanzhou 730070, China.
Sci Total Environ. 2020 Jun 25;723:138081. doi: 10.1016/j.scitotenv.2020.138081. Epub 2020 Mar 20.
Concentration gradients of multiple heavy metals (HMs) in the arid loess region near a smelter were determined. In order to understand the response of soil microbes to multiple HM gradients, bacterial and fungal community structures and functions were analyzed using high-throughput RNA gene sequencing and the PICRUSt method. RDA/PCA analyses revealed that soil pH, HMs, and electrical conductivity (EC) jointly affected the bacterial communities in the soils. The soil microbial community structures responded differently to HMs, EC, and pH. High HMs increased the abundances of the bacterial phyla Actinobacteria, Bacteroidetes, Deinococcus-Thermus, and Chloroflexi, and the genera Blastococcus, Rubrobacter, Quadrisphaera, and Tunicatimonas, whereas they decreased the abundances of the phyla Proteobacteria and Acidobacteria and the genera Streptomyces and Nocardioides. High EC and low pH decreased the abundance of most of the dominant bacterial phyla but increased the abundances of Firmicutes, Deinococcus-Thermus, and Nitrospirae. Furthermore, high HMs and EC reduced the numbers of soil-specific bacterial and fungal groups and drove the succession of certain groups that were highly resistant to increased HMs and EC. In addition, many bacterial and fungal groups exhibited different response patterns to each HM, implying that, in multiple HM-contaminated soils, HMs jointly shaped the microbial communities. PICRUSt analysis suggested that high HMs significantly decreased the total gene abundance and most KEGG modules in the soils. High EC and low pH significantly enhanced the abundances of several two-component system-, electron transfer-, and methanogenesis-related modules. We conclude that excessive multiple HMs and EC principally repressed the microbial activity and severely drove the gradient succession of bacterial and fungal communities in the arid loess region.
测定了冶炼厂附近干旱黄土区多种重金属（HM）的浓度梯度。为了了解土壤微生物对多种 HM 梯度的响应，我们使用高通量 RNA 基因测序和 PICRUSt 方法分析了细菌和真菌群落结构和功能。RDA/PCA 分析表明，土壤 pH、HM 和电导率（EC）共同影响土壤中的细菌群落。土壤微生物群落结构对 HM、EC 和 pH 的响应不同。高 HM 增加了放线菌门、拟杆菌门、厚壁菌门、Chloroflexi 门和芽胞杆菌属、Rubrobacter 属、Quadrisphaera 属和 Tunicatimonas 属的丰度，而降低了变形菌门和酸杆菌门以及链霉菌属和诺卡氏菌属的丰度。高 EC 和低 pH 降低了大多数优势细菌门的丰度，但增加了厚壁菌门、厚壁菌门、热脱硫菌门和硝化螺旋菌门的丰度。此外，高 HM 和 EC 减少了土壤特异性细菌和真菌类群的数量，并促使某些对高 HM 和 EC 高度耐受的类群演替。此外，许多细菌和真菌类群对每种 HM 表现出不同的响应模式，这意味着在多种 HM 污染的土壤中，HM 共同塑造了微生物群落。PICRUSt 分析表明，高 HM 显著降低了土壤中的总基因丰度和大多数 KEGG 模块。高 EC 和低 pH 显著增强了几个二组分系统、电子传递和产甲烷相关模块的丰度。我们得出结论，过多的多种 HM 和 EC 主要抑制了微生物活性，并严重驱动了干旱黄土区细菌和真菌群落的梯度演替。
