State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
J Hazard Mater. 2024 Sep 5;476:134896. doi: 10.1016/j.jhazmat.2024.134896. Epub 2024 Jun 13.
Cadmium(Cd) contamination can exert significantly adverse effects on soil microbiota in reclaimed areas, however, its effects on bacterial network structure are still limitedly understood. Here we collected soil samples from typical reclaimed wetlands (RW) and ditch wetlands (DW) in coastal reclamation areas and examined the effects of Cd contamination on the bacterial network complexity and stability. The results showed that the bacterial networks were destabilized by the Cd contamination, while bacteria in DW soils showed robust invulnerability characterized by higher node constancy and compositional stability compared with RW soils. Soil bacteria resisted Cd stress by forming a network with intensive connections in the module but sparser connections among the modules. Especially, network modularity was higher in DW soils than in RW soils, but made it more vulnerable to nodes removal. In addition, Cd contamination promoted bacterial positive cohesion but decreased negative cohesion in RW soils. Flavobacteriaceae, Xanthomonadaceae, and Alcaligenaceae were identified as core phylotypes, which played pivotal roles in regulating interspecies interactions due to higher contributions to cohesion and significant correlations with soil nutrients. The findings of this work indicate the changes of bacterial network structure and the indispensable role of core phylotypes in regulating interactions and maintaining network sustainability under Cd contamination.
镉（Cd）污染会对开垦区的土壤微生物群产生显著的不利影响，但人们对其对细菌网络结构的影响仍知之甚少。本研究采集了沿海开垦区典型围垦湿地（RW）和沟渠湿地（DW）的土壤样本，研究了镉污染对细菌网络复杂性和稳定性的影响。结果表明，镉污染会使细菌网络不稳定，而 DW 土壤中的细菌表现出较强的抗逆性，表现为节点恒定性和组成稳定性较高，与 RW 土壤相比。土壤细菌通过在模块中形成密集连接而在模块间形成稀疏连接来抵抗镉胁迫。特别是，DW 土壤的网络模块性高于 RW 土壤，但使其更容易受到节点去除的影响。此外，镉污染促进了 RW 土壤中细菌正凝聚，但降低了负凝聚。黄杆菌科、黄单胞菌科和产碱杆菌科被鉴定为核心类群，由于它们对凝聚的贡献更高，与土壤养分的显著相关性，它们在调节种间相互作用方面发挥着关键作用。本研究结果表明，在镉污染下，细菌网络结构发生变化，核心类群在调节相互作用和维持网络可持续性方面发挥着不可或缺的作用。
