State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China.
State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, China.
J Hazard Mater. 2019 Apr 5;367:99-108. doi: 10.1016/j.jhazmat.2018.12.071. Epub 2018 Dec 19.
Understanding environmental and spatial gradient influences on sediment microbial communities, especially the communities of highly contaminated subsurface sediments, has received great attention with respect to natural attenuation and bioremediation. Here, we investigated the spatial variation and the co-occurrence patterns of microbial communities in polycyclic aromatic hydrocarbon (PAH)-contaminated riverine sediments by using spatial-series 16S rRNA gene data. The results showed that species from the surface and subsurface sediment samples tended to show greater co-occurrence patterns and facilitative interactions in the sediment microbial community as environmental severity increased. Microorganisms in the heavier PAH-contaminated sediment have stronger relationships and are more centrally clustered within the network compared to microorganisms in the lower PAH-contaminated sediment. The core communities harbored the keystone species (Dechloromonas, Crenothrix, Desulfuromonadales, Xanthomonadales, Anaerolineaceae and Dehalococcoidales), which responded to changes in the environmental and spatial gradients. The sediment PAH concentrations, ferrous iron and vertical distance were identified as the main drivers in determining the bacterial community assembly. The keystone species were linked to PAHs biodegradation coupled with iron cycling in sediments and could orchestrate core communities to perform ecosystem processes. Overall, these findings provide new insight into microbial community assembly and contribute to harnessing their functions in ecosystems for bioremediation.
了解环境和空间梯度对沉积物微生物群落的影响，特别是对高度污染的地下沉积物微生物群落的影响，对于自然衰减和生物修复受到了极大的关注。在这里，我们通过使用空间序列 16S rRNA 基因数据研究了多环芳烃（PAH）污染河流沉积物中微生物群落的空间变化和共现模式。结果表明，随着环境严重程度的增加，表层和底层沉积物样品中的物种在沉积物微生物群落中表现出更大的共现模式和促进相互作用。与低 PAH 污染沉积物中的微生物相比，较重 PAH 污染沉积物中的微生物具有更强的关系，并且在网络内的中心聚类程度更高。核心群落中存在着关键物种（脱氯单胞菌、纤发菌属、脱硫单胞菌目、黄单胞菌目、产甲烷菌科和脱氯螺菌目），它们对环境和空间梯度的变化有响应。沉积物中 PAH 浓度、亚铁和垂直距离被确定为决定细菌群落组装的主要驱动因素。关键物种与 PAHs 生物降解以及沉积物中的铁循环有关联，它们可以协调核心群落来执行生态系统过程。总的来说，这些发现为微生物群落组装提供了新的见解，并有助于利用它们在生态系统中的功能进行生物修复。
