State Key Laboratory of Organic Geochemistry and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100039, China.
State Key Laboratory of Organic Geochemistry and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100039, China.
J Hazard Mater. 2024 Oct 5;478:135513. doi: 10.1016/j.jhazmat.2024.135513. Epub 2024 Aug 20.
Endophytic bacteria can promote plant growth and accelerate pollutant degradation. However, it is unclear whether endophytic consortia (Consortium_E) can stabilize colonisation and degradation. We inoculated Consortium_E into the rhizosphere to enhance endophytic bacteria survival and promote pollutant degradation. Rhizosphere-inoculated Consortium_E enhanced polycyclic aromatic hydrocarbon (PAH) degradation rates by 11.5-13.1 % compared with sole bioaugmentation and plant treatments. Stable-isotope-probing (SIP) showed that the rhizosphere-inoculated Consortium_E had the largest number of degraders (8 amplicon sequence variants). Furthermore, only microbes from Consortium_E were identified among the degraders in bioaugmentation treatments, indicating that directly participated in phenanthrene metabolism. Interestingly, Consortium_E reshaped the community structure of degraders without significantly altering the rhizosphere community structure, and strengthened the core position of degraders in the network, facilitating close interactions between degraders and non-degraders in the rhizosphere, which were crucial for ensuring stable functionality. The synergistic effect between plants and Consortium_E significantly enhanced the upregulation of aromatic hydrocarbon degradation and auxiliary degradation pathways in the rhizosphere. These pathways showed a non-significant increasing trend in the uninoculated rhizosphere compared with the control, indicating that Consortium_E primarily promotes rhizosphere effects. Our results explore the Consortium_E bioaugmentation mechanism, providing a theoretical basis for the ecological restoration of contaminated soils.
内生细菌可以促进植物生长并加速污染物降解。然而，目前尚不清楚内生菌群（Consortium_E）是否可以稳定定殖和降解。我们将内生菌群接种到根际中，以增强内生细菌的生存能力并促进污染物降解。与单独的生物强化和植物处理相比，根际接种内生菌群使多环芳烃（PAH）的降解率提高了 11.5-13.1%。稳定同位素探针（SIP）显示，根际接种内生菌群的降解菌数量最多（8 个扩增子序列变体）。此外，在生物强化处理中，只有内生菌群中的微生物被鉴定为降解菌，表明它们直接参与了菲的代谢。有趣的是，内生菌群重塑了降解菌的群落结构，而没有显著改变根际群落结构，并且强化了网络中降解菌的核心地位，促进了根际中降解菌和非降解菌之间的紧密相互作用，这对于确保稳定的功能至关重要。植物和内生菌群之间的协同作用显著增强了芳烃降解和辅助降解途径在根际中的上调。与对照相比，这些途径在未接种根际中的非显著增加趋势表明，内生菌群主要促进了根际效应。我们的研究结果探索了内生菌群的生物强化机制，为污染土壤的生态修复提供了理论基础。
