Data_Sheet_1_Community Assembly and Co-occurrence Patterns Underlying the Core and Satellite Bacterial Sub-communities in the Tibetan Lakes.docx

Microbial communities normally comprise a few core species and large numbers of satellite species. These two sub-communities have different ecological and functional roles in natural environments, but knowledge on the assembly processes and co-occurrence patterns of the core and satellite species in Tibetan lakes is still sparse. Here, we investigated the ecological processes and co-occurrence relationships of the core and satellite bacterial sub-communities in the Tibetan lakes via 454 sequencing of 16S rRNA gene. Our studies indicated that the core and satellite bacterial sub-communities have similar dominant phyla (Proteobacteria, Bacteroidetes, and Actinobacteria). But the core sub-communities were less diverse and exhibited a stronger distance-decay relationship than the satellite sub-communities. In addition, topological properties of nodes in the network demonstrated that the core sub-communities had more complex and stable co-occurrence associations and were primarily driven by stochastic processes (58.19%). By contrast, the satellite sub-communities were mainly governed by deterministic processes (62.17%). Overall, this study demonstrated the differences in the core and satellite sub-community assembly and network stability, suggesting the importance of considering species traits to understand the biogeographic distribution of bacterial communities in high-altitude lakes.

微生物群落通常由少数核心物种和大量卫星物种组成。这两种亚群落天然环境中扮演着不同的生态和功能角色，然而，关于西藏湖泊中核心与卫星物种的组装过程及共现模式的认知仍相对匮乏。本研究通过对西藏湖泊核心与卫星细菌亚群落进行16S rRNA基因的454测序，探究了其生态过程及共现关系。研究结果表明，核心与卫星细菌亚群落具有相似的支配门类（变形菌门、拟杆菌门和放线菌门）。然而，核心亚群落多样性较低，且表现出比卫星亚群落更强的距离衰减关系。此外，网络中节点拓扑属性表明，核心亚群落具有更为复杂和稳定的共现关联，且主要受随机过程驱动（占比58.19%）。相比之下，卫星亚群落主要由确定性过程控制（占比62.17%）。总体而言，本研究揭示了核心与卫星亚群落组装及网络稳定性的差异，强调了在理解高海拔湖泊中细菌群落生物地理分布时考虑物种特性的重要性。