School of Environmental Science and Engineering, Donghua University, Shanghai, China.
School of Environmental Science and Engineering, Donghua University, Shanghai, China.
Chemosphere. 2021 Jun;273:129496. doi: 10.1016/j.chemosphere.2020.129496. Epub 2021 Jan 2.
Vermiremediation on improvement of antimony (Sb) and cadmium (Cd) contaminated soil was less reported. In this study, earthworm Eisenia fetida was exposed into soil spiked with Sb and Cd and their mixture for 30 days, and then we measured multiple soil enzyme activities and bacteria communities via enzymatic reaction and high-throughput sequencing of 16 S rRNA genes. The results showed that Sb and Cd at high treatment levels inhibited the activities of urease, neutral phosphatase and protease significantly, but earthworm could promote the activities of urease and neutral phosphatase by 17.75%-121.91% and 1.46%-118.97%, respectively. However, earthworms inhibited catalase and had no effect on protease. The Geometric Mean Index suggested that earthworms led to a higher soil biochemistry function. According to a taxonomic analysis, bacterial community structure predominantly consisted of phylum Proteobacteria, Actinobacteria, Firmicutes, etc. and class Gammaproteobacteria, Actinobacteria, Alphaproteobacteria, etc.; furthermore, Pielou index and Shannon index (Alpha diversity in the habitat) indicated that bacteria diversity and evenness increased in the presence of earthworms. The heating map revealed that earthworms made genus Sphingomonas, Flavobacterium, etc. and species Sphingomonas jaspsi, Conexibacter, etc. dominate. Overall, earthworm is a suitable remediation species to improve the ecological function of heavy metal polluted soil. However, the specific mechanism and causal relationship of how earthworm to control enzyme activity and bacteria community remained to be explored.
蚯蚓修复对改善锑（Sb）和镉（Cd）污染土壤的作用研究较少。本研究采用添加 Sb 和 Cd 及其混合物的土壤，暴露 30 天后，通过酶促反应和 16S rRNA 基因高通量测序，测定了多种土壤酶活性和细菌群落。结果表明，高处理水平的 Sb 和 Cd 显著抑制了脲酶、中性磷酸酶和蛋白酶的活性，但蚯蚓可分别促进脲酶和中性磷酸酶的活性 17.75%-121.91%和 1.46%-118.97%。然而，蚯蚓抑制了过氧化氢酶，对蛋白酶没有影响。几何均数指数表明，蚯蚓导致了更高的土壤生物化学功能。根据分类分析，细菌群落结构主要由门变形菌门、放线菌门、厚壁菌门等和纲γ-变形菌纲、放线菌纲、α-变形菌纲等组成；此外，Pielou 指数和 Shannon 指数（生境中的 Alpha 多样性）表明，蚯蚓的存在增加了细菌的多样性和均匀度。热图显示，蚯蚓使鞘氨醇单胞菌属、黄杆菌属等和种 Sphingomonas jaspsi、 Conexibacter 等成为优势属和种。总体而言，蚯蚓是一种适合改善重金属污染土壤生态功能的修复物种。然而，蚯蚓如何控制酶活性和细菌群落的具体机制和因果关系仍有待探索。
