State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; Department of Municipal Engineering, School of Civil Engineering, Southeast University, Nanjing 210096, China.
State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
J Hazard Mater. 2022 Mar 5;425:127767. doi: 10.1016/j.jhazmat.2021.127767. Epub 2021 Nov 22.
Rhizodegradation using submersed macrophytes Vallisneria natans (V. natans) is a promising biotechnology with the potential to restore polycyclic aromatic hydrocarbon (PAH)-contaminated sediments. However, how different sediment types influence the rhizoremediation outcome and the characterization of microbial community along the sediment-V. natans continuum is poorly understood. Here, we collect V. natans, sediments and overlying water from two types of vegetation zones with different levels of PAHs pollutions and set up sediment microcosms for phytoremediation tests. V. natans presence was particularly useful for PAHs remediation in the highly contaminated sites and had a significant effect on PAHs rhizodegradation and microbial communities, especially rhizosphere sediments. The structural composition of microbial communities along the sediment-plant continuum was shaped predominantly by compartment niche of V. natans. Moreover, selective enrichment of specific microbial taxa like Herbaspirillum (relative abundance = 94.80%) in endosphere of V. natans was observed. Herbaspirillum could use PAH as carbon source and promote the growth of plants. In the highly contaminated sediment, V. natans could recruit these bacteria for toxicant degradation into the root interior. Thus, understanding the complex V. natans-microbe interactions could help set up novel decontamination strategies based on the rhizosphere and root interior interactions between plants and their microbial associates.
沉水植物水蕴草（Vallisneria natans）的根际降解是一种很有前途的生物技术，具有修复多环芳烃（PAH）污染沉积物的潜力。然而，不同类型的沉积物如何影响根际修复效果，以及微生物沿沉积物-水蕴草连续体的特征，目前还了解甚少。在这里，我们从两种受 PAH 污染程度不同的植被带收集水蕴草、沉积物和上覆水，并建立沉积物微宇宙进行植物修复试验。水蕴草的存在对高污染地区的 PAHs 修复特别有用，对 PAHs 的根际降解和微生物群落有显著影响，特别是根际沉积物。微生物群落沿沉积物-植物连续体的结构组成主要由水蕴草的隔室生态位决定。此外，还观察到一些特定微生物类群在水蕴草的根内（相对丰度=94.80%）的选择性富集，如水生螺菌属（Herbaspirillum）。水生螺菌可以利用 PAH 作为碳源，并促进植物的生长。在高度污染的沉积物中，水蕴草可以将这些细菌招募到根内部进行有毒物质的降解。因此，了解水蕴草与微生物之间的复杂相互作用，可以帮助我们基于植物与其微生物伙伴之间的根际和根内相互作用，建立新的污染降解策略。
