Min Xiaobo, Wang Yangyang, Chai Liyuan, Yang Zhihui, Liao Qi
Institute of Environmental Science and Engineering, School of Metallurgy and Environment, Central South University, 410083, Changsha, China; National Engineering Research Center for Heavy Metals Pollution Control and Treatment, 410083, Changsha, China.
Institute of Environmental Science and Engineering, School of Metallurgy and Environment, Central South University, 410083, Changsha, China; College of Environment and Planning, Henan University, 475004, Kaifeng, China.
Chemosphere. 2017 Sep;183:266-276. doi: 10.1016/j.chemosphere.2017.05.105. Epub 2017 May 21.
To explore how heavy metal contamination in Chromite Ore Processing Residue (COPR) disposal sites determine the dissimilarities of indigenous microbial communities, 16S rRNA gene MiSeq sequencing and advanced statistical methods were applied. 13 soil samples were collected from three COPR disposal sites in Mouding of southwestern, Shangnan of northwestern and Yima of central China. The results of analyses of variance (ANOVA), similarities (ANOSIM), and non-metric multidimensional scaling (NMDS) showed that the structural diversity of the microbial communities in the samples with high total chromium (Cr) content (more than 300 mg kg; High group) were significantly lesser than in the Low group (less than 90 mg kg) regardless of their geographical distribution. But their diversity had virtually rehabilitated under the pressures of long-term metal contamination. Furthermore, the similarity percentage (SIMPER) analysis indicated that the major dissimilarity contributors Micrococcaceae, Delftia, and Streptophyta, possibly having Cr(VI)-resistant and/or Cr(VI)-reducing capability, were dominant in the High group, while Ramlibacter and Gemmatimonas with potential resistances to other heavy metals were prevalent in the Low group. In addition, the multivariate regression tree (MRT), aggregated boosted tree (ABT), and Mantel test revealed that total Cr content affiliated with Cr(VI) was the principal factor shaping the dissimilarities between the soil microbial communities in the COPR sites. Our findings provide a deep insight of the influence of these heavy metals on the microbial communities in the COPR disposal sites and will facilitate bioremediation on such site.
为探究铬铁矿加工残渣（COPR）处置场地中的重金属污染如何决定本地微生物群落的差异，应用了16S rRNA基因MiSeq测序和先进的统计方法。从中国西南部牟定、西北部商南和中部义马的三个COPR处置场地采集了13份土壤样本。方差分析（ANOVA）、相似性分析（ANOSIM）和非度量多维尺度分析（NMDS）结果表明，无论地理分布如何，总铬（Cr）含量高的样本（超过300 mg/kg；高组）中微生物群落的结构多样性显著低于低组（低于90 mg/kg）。但在长期金属污染的压力下，它们的多样性实际上已经恢复。此外，相似性百分比（SIMPER）分析表明，高组中主要的差异贡献菌微球菌科、代尔夫特菌属和链形植物可能具有抗Cr(VI)和/或还原Cr(VI)的能力，而低组中对其他重金属具有潜在抗性的拉恩氏菌属和芽单胞菌属较为普遍。此外，多元回归树（MRT）、聚合增强树（ABT）和Mantel检验表明，与Cr(VI)相关的总Cr含量是塑造COPR场地土壤微生物群落差异的主要因素。我们的研究结果深入洞察了这些重金属对COPR处置场地微生物群落的影响，并将促进此类场地的生物修复。
