Zhang Fen-Guo, Wu Kefan, Zhang Sanqing, Liang Furong, Du Zhihua, Wang Yongji, Zhang Quan-Guo
College of Life Science, Shanxi Engineering Research Center of Microbial Application Technologies, Shanxi Normal University, Taiyuan, China.
State Key Laboratory of Earth Surface Processes and Resource Ecology, MOE Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, China.
Front Microbiol. 2025 Jan 7;15:1508136. doi: 10.3389/fmicb.2024.1508136. eCollection 2024.
To investigate the influence of immigration on the selection in structuring local water bacterial communities, we conducted a new community assembly experiment using microcosms filled with sterile original water medium under outdoor conditions. We collected air particulate matter from dust pooled from samples collected at 10 locations across ~20 km in a warm temperate region in Linfen City (northern China). The immigration rates were increased by introducing air particulate matter into the microcosms. The diversity, structure, and composition of the bacterial community in the water were assessed using 16S rRNA gene amplicon sequencing on the 13th and 60th days after the start of the experiment. Our results showed that increasing immigration did not lead to significant changes in the overall diversity of the total bacterial community on the 13th day. However, on the 60th day, diversity significantly increased. The variation explained by the environment substantially decreased from the 13th to the 60th day. The amount decreased from the control to the high immigration treatments, with a range of 65.0 to 29.8% on the 13th day and 34.0 to 15.4% on the 60th day. The dominant phyla differed significantly. In the early stage, Proteobacteria (69.6%) accounted for a higher relative average abundance, while Firmicutes (4.6%), Cyanobacteria (6.0%), Planctomycetota (8.1%), Verrucomicrobiota (2.0%), and Halobacterota (0.9%) were more abundant in the late stage. Additionally, the late stage had an average of 33 phyla, compared to 15 phyla in the early stage. All the results suggested a minimal role of dispersal limitation in structuring water bacterial communities in the early stage, whereas, in the late stage, the bacterial communities might experience dispersal swamping in our study area. Variance partitioning indicated that throughout the experiment, increasing immigration weakened the signal of environmental selection in the water microbial community assembly. These results expand our understanding of the impact of immigration on environmental selection and provide insights into the varying importance of dispersal and selection on microbial community assembly at different stages of succession.
为了研究移民对构建当地水体细菌群落选择的影响，我们在室外条件下使用装有无菌原水培养基的微宇宙进行了一项新的群落组装实验。我们从中国北方临汾市一个暖温带地区约20公里范围内10个地点采集的灰尘样本中收集空气颗粒物。通过向微宇宙中引入空气颗粒物来提高移民率。在实验开始后的第13天和第60天，使用16S rRNA基因扩增子测序评估水中细菌群落的多样性、结构和组成。我们的结果表明，在第13天，移民增加并未导致总细菌群落的总体多样性发生显著变化。然而，在第60天，多样性显著增加。从第13天到第60天，环境解释的变异大幅减少。该量从对照到高移民处理逐渐减少，第13天的范围为65.0%至29.8%，第60天为34.0%至15.4%。优势菌门有显著差异。在早期，变形菌门（69.6%）的相对平均丰度较高，而在后期厚壁菌门（4.6%）、蓝细菌门（6.0%）、浮霉菌门（8.1%）、疣微菌门（2.0%）和盐杆菌门（0.9%）更为丰富。此外，后期平均有33个菌门，而早期为15个菌门。所有结果表明，在早期，扩散限制在构建水体细菌群落中作用极小，而在后期，我们研究区域的细菌群落可能经历扩散淹没。方差分解表明，在整个实验过程中，移民增加削弱了水微生物群落组装中环境选择的信号。这些结果扩展了我们对移民对环境选择影响的理解，并为演替不同阶段扩散和选择对微生物群落组装的不同重要性提供了见解。
