School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, PR China.
School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, PR China.
Chemosphere. 2022 Sep;302:134829. doi: 10.1016/j.chemosphere.2022.134829. Epub 2022 May 3.
Persistent heavy metal (HM) contaminated soil provides special habitat for microorganisms, HM stress and complex abiotic factors bring great uncertainty for the development of bacteria and eukaryotic microbes. Despite numerous studies about HMs' effect on soil microorganisms, the key factors affecting microbial communities in severe HM contaminated soil and their interactions are still not definite. In this study, the effect of HM fractions and soil properties on the interaction between bacterial communities and eukaryotic microorganisms was studied by high-throughput Illumina sequencing and simplified continuous extraction of HM in severe HM contaminated soil. Based on amplification and sequencing of the 18S rRNA gene, this study revealed that protists and algae were the most predominant eukaryotic microorganisms, and the dominant phyla were SAR, Opisthokonta and Archaeplastida in HM seriously polluted soil. These results also showed that exchangeable As was negatively correlated with bacterial Shannon and Simpson indexes, while exchangeable Zn was positively correlated with Shannon and Simpson indexes of eukaryotic microbes. Moreover, the structural equation model illustrated that pH, moisture content, available potassium and phosphorus, and exchangeable Cd, As and Zn were the dominant factors shaping bacterial communities, while total organic carbon and exchangeable Zn made the predominant contributions to variations in eukaryotic microbes. In addition, eukaryotic microbes were intensely affected by the bacterial communities, with a standardized regression weight of 0.53, which exceeded the influence of other abiotic factors. It was suggested that community-level adaptions through cooperative interactions under serious HM stress in soil.
持久性重金属 (HM) 污染土壤为微生物提供了特殊的栖息地，HM 胁迫和复杂的非生物因素给细菌和真核微生物的发展带来了极大的不确定性。尽管有大量关于 HMs 对土壤微生物影响的研究，但严重 HM 污染土壤中影响微生物群落的关键因素及其相互作用仍不确定。在这项研究中，通过高通量 Illumina 测序和简化的连续提取严重 HM 污染土壤中的 HM 分数和土壤特性，研究了 HM 分数和土壤特性对细菌群落与真核微生物相互作用的影响。基于 18S rRNA 基因的扩增和测序，本研究揭示了原生动物和藻类是最主要的真核微生物，而在严重 HM 污染土壤中，优势门为 SAR、Opisthokonta 和 Archaeplastida。这些结果还表明，可交换的 As 与细菌 Shannon 和 Simpson 指数呈负相关，而可交换的 Zn 与真核微生物的 Shannon 和 Simpson 指数呈正相关。此外，结构方程模型表明，pH、含水量、有效钾和磷以及可交换的 Cd、As 和 Zn 是塑造细菌群落的主要因素，而总有机碳和可交换的 Zn 对真核微生物的变异贡献最大。此外，真核微生物受到细菌群落的强烈影响，标准化回归权重为 0.53，超过了其他非生物因素的影响。这表明在严重的 HM 胁迫下，土壤中的群落水平适应是通过合作相互作用实现的。
