Menéndez-Serra Mateu, Cáliz Joan, Triadó-Margarit Xavier, Alonso David, Casamayor Emilio O
Ecology of the Global Microbiome-Department of Ecology and Complexity, Centre of Advanced Studies of Blanes (CEAB), Spanish Research Council (CSIC), Blanes, Catalonia, Spain.
Centre for Ancient Environmental Genomics, Globe Institute, University of Copenhagen, Copenhagen, Denmark.
Environ Microbiol. 2024 Dec;26(12):e70019. doi: 10.1111/1462-2920.70019.
Selection and dispersal are the primary processes influencing community assembly at both global and regional scales. Although the effectiveness of dispersal is often examined within the same biome, microscopic organisms demonstrate the capability to colonise and thrive across different biomes. In this study, we evaluated the relationship between (i) aquatic, (ii) sedimentary and (iii) aerial microbial communities, and how local selective pressures influence the potential impact of inter-biome dispersal, focusing on the salinity gradient stress over time in ephemeral saline lakes. Our taxonomic ordination analyses revealed that the three communities were distinctly segregated yet interconnected by shared populations. Organisms prevalent across the three biomes exhibited cosmopolitan behaviour based on global databases, indicating an inherent ability to cross biome boundaries. Cosmopolitan groups dominated the planktonic community at lower salinities but gradually diminished as salinity increased, resulting in communities dominated by aquatic specialists with more restricted environmental distributions. The aerial community was primarily composed of generalists, although airborne halophiles were also identified, suggesting long-range dispersal as a source of colonisers in isolated extremophile environments. Our findings contribute to a better understanding of the dynamic interplay between dispersal and selective pressures on community assembly across biomes, highlighting the significance of aerial microbiota in remote colonisation.
选择和扩散是在全球和区域尺度上影响群落组装的主要过程。尽管扩散的有效性通常在同一生物群落中进行研究，但微生物显示出跨越不同生物群落定殖和繁衍的能力。在本研究中，我们评估了（i）水生、（ii）沉积和（iii）空气微生物群落之间的关系，以及局部选择压力如何影响生物群落间扩散的潜在影响，重点关注临时盐湖中随时间变化的盐度梯度压力。我们的分类排序分析表明，这三个群落虽然明显分离，但通过共享种群相互联系。基于全球数据库，在三个生物群落中普遍存在的生物表现出世界性的行为，表明它们具有跨越生物群落边界的内在能力。世界性类群在低盐度下主导浮游生物群落，但随着盐度增加逐渐减少，导致群落由环境分布更受限的水生 specialists 主导。空气群落主要由 generalists 组成，尽管也鉴定出了空气嗜盐菌，这表明远距离扩散是孤立极端环境中定殖者的一个来源。我们的研究结果有助于更好地理解生物群落间扩散和选择压力对群落组装的动态相互作用，突出了空气微生物群落在远程定殖中的重要性。
