College of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai, 200444, China.
College of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai, 200444, China.
Chemosphere. 2020 Feb;241:125027. doi: 10.1016/j.chemosphere.2019.125027. Epub 2019 Oct 1.
The aim of this study was to investigate whether the plant-growth-promoting rhizobacteria (PGPR) could enhance phytoremediation efficiency of Scirpus triqueter (S.triqueter) in the pyrene-Ni co-contaminated soil. We also expected to reveal the possible mechanism for the affected phytoremediation efficiency induced by PGPR. We used three kinds of contaminated soils (Ni-contaminated soil, pyrene-contaminated soil and pyrene-Ni co-contaminated soil) to conduct this pot study. After harvest, plants growth indicators, polyphenol oxidase (PPO) activity and soil microbial community structure of each treatment were investigated to explain the different dissipation rates of pyrene and removal rates of Ni between treatments with and without PGPR. The results showed that PGPR-inoculated S. triqueter increased dissipation rates of pyrene and removal rates of Ni in all three contaminated soils, among which Ni removal rates in Ni single contaminated soil was elevated most significantly, from 0.895‰ to 8.8‰, increasing nearly 9 folds. However, Ni removal rate efficiency in co-contaminated soil was weakened because more toxic and complicated co-contaminated soil restrained plant growth and Ni absorption. We also observed that co-contamination harmed the soil microbial community more severely than that in single pyrene or Ni contaminated soil through phospholipid fatty acids analysis. Furthermore, dissipation rates of pyrene and removal rates of Ni were found positively correlated to the PPO activity and the abundance of branched and saturated fatty acids reflected by Pearson correlation analysis.
本研究旨在探讨植物促生根际细菌（PGPR）是否能提高香蒲（S.triqueter）在芘-镍复合污染土壤中的植物修复效率。我们还期望揭示 PGPR 对植物修复效率的影响可能的机制。我们使用三种污染土壤（镍污染土壤、芘污染土壤和芘-镍复合污染土壤）进行盆栽研究。收获后，对每个处理的植物生长指标、多酚氧化酶（PPO）活性和土壤微生物群落结构进行了调查，以解释有和没有 PGPR 处理之间芘的不同消解率和镍的去除率。结果表明，PGPR 接种的香蒲提高了所有三种污染土壤中芘的消解率和镍的去除率，其中在镍单污染土壤中镍的去除率提高最显著，从 0.895‰增加到 8.8‰，增加了近 9 倍。然而，由于毒性更大、更复杂的复合污染土壤抑制了植物生长和镍吸收，复合污染土壤中的镍去除率效率减弱。通过磷脂脂肪酸分析，我们还观察到，与单一芘或镍污染土壤相比，复合污染对土壤微生物群落的危害更大。此外，通过皮尔逊相关性分析，芘的消解率和镍的去除率与 PPO 活性和反映分支和饱和脂肪酸的丰度呈正相关。
