College of Agriculture, Forestry and Life Science, Qiqihar University, Qiqihar 161006, PR China; Lancaster Environment Centre, Lancaster University, Lancaster LA1 2YW, United Kingdom.
Research Institute for Environmental Innovation (Suzhou), Tsinghua, Suzhou 215163, PR China.
Sci Total Environ. 2019 Dec 20;697:134148. doi: 10.1016/j.scitotenv.2019.134148. Epub 2019 Aug 27.
Phytoremediation is an effective approach to control soil heavy metal pollution. This study isolated a fungus strain from soils contaminated by cadmium (Cd) and lead (Pb) in Zhalong Wetland (China), which was identified as Simplicillium chinense QD10 via both genotypic and phenotypic analysis. The performance and mechanism of S. chinense QD10 in Cd and Pb adsorption was unraveled by morphological analysis and biosorption test, and its roles in ameliorating phytoremediation by Phragmites communis were tested in pot-experiments. Cd biosorption was attributed to the formation of Cd-chelate, whereas Pb was predominantly adsorbed by extracellular polymeric substances. Metal biosorption followed Langmuir isotherm, and the maximum biosorption capacity was 88.5 and 57.8 g/kg for Cd and Pb, respectively. Colonized in soils, such biosorption behavior of S. chinense QD10 can generate gradients of available Cr or Pb and drive their enrichment. Accordingly, S. chinense QD10 amendment significantly enhanced the phytoextraction of Cd and Pb by P. communis, possibly attributing to rhizospheric enrichment of Cd or Pb and defending effects on plants, explained by the significant removal of acid-extractable and reducible metals in soils and the increase of Cd and Pb content in P. communis tissues. The present study explored the mechanisms of S. chinense QD10 in Cd and Pb biosorption and proved its potential in ameliorating the phytoremediation performance at metal contaminated sites.
植物修复是控制土壤重金属污染的有效方法。本研究从中国扎龙湿地受镉（Cd）和铅（Pb）污染的土壤中分离出一株真菌，通过基因型和表型分析鉴定为中华束丝孢（Simplicillium chinense）QD10。通过形态分析和生物吸附试验揭示了 S. chinense QD10 对 Cd 和 Pb 吸附的性能和机制，并通过盆栽试验测试了其在改善香蒲（Phragmites communis）植物修复中的作用。Cd 的生物吸附归因于 Cd-螯合物的形成，而 Pb 主要通过胞外聚合物吸附。金属生物吸附符合朗缪尔等温线，Cd 和 Pb 的最大生物吸附容量分别为 88.5 和 57.8 g/kg。在土壤中定殖时，S. chinense QD10 的这种生物吸附行为会产生可利用的 Cr 或 Pb 梯度，并驱动其富集。因此，S. chinense QD10 的添加显著增强了香蒲对 Cd 和 Pb 的植物提取，这可能归因于 Cd 或 Pb 在根际的富集以及对植物的保护作用，这可以通过土壤中酸提取和可还原金属的显著去除以及 P. communis 组织中 Cd 和 Pb 含量的增加来解释。本研究探讨了 S. chinense QD10 在 Cd 和 Pb 生物吸附中的作用机制，并证明了其在改善金属污染场地植物修复性能方面的潜力。
