State Key Laboratory of Marine Environmental Science, Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies, Xiamen University, Xiamen, Fujian, China.
Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, Fujian, China.
Microbiol Spectr. 2022 Feb 23;10(1):e0079821. doi: 10.1128/spectrum.00798-21. Epub 2022 Jan 12.
Marine microbiota are critical components of global biogeochemical cycles. However, the biogeographic patterns and ecological processes that structure them remain poorly understood, especially in the oligotrophic ocean. In this study, we used high-throughput sequencing of 16S and 18S rRNA genes to investigate the distribution patterns of bacterial and microeukaryotic communities and their assembly mechanisms in the surface waters of the tropical North Pacific Ocean. The fact that both the bacterial and the microeukaryotic communities showed similar distribution patterns (i.e., similar distance-decay patterns) and were clustered according to their geographic origin (i.e., the western tropical North Pacific and central tropical North Pacific) suggested that there was a significant biogeographic pattern of microbiota in the North Pacific Ocean. Indices of alpha diversity such as species richness, phylogenetic diversity, and the Shannon diversity index also differed significantly between regions. The correlations were generally similar between spatial and environmental variables and the alpha and beta diversities of bacteria and microeukaryotes across the entire region. The relative importance of ecological processes differed between bacteria and microeukaryotes: ecological drift was the principal mechanism that accounted for the structure of bacterial communities; heterogeneous selection, dispersal limitation, and ecological drift collectively explained much of the turnover of the microeukaryote communities. Bacteria and microeukaryotes are extremely diverse groups in the ocean, where they regulate elemental cycling and energy flow. Studies of marine microbial ecology have benefited greatly from the rapid progress that has been made in genomic sequencing and theoretical microbial ecology. However, the spatial distribution of marine bacteria and microeukaryotes and the nature of the assembly mechanisms that determine their distribution patterns in oligotrophic marine waters are poorly understood. In this study, we used high-throughput sequencing methods to identify the distribution patterns and ecological processes of bacteria and microeukaryotes in an oligotrophic, tropical ocean. Our study showed that contrasting community assembly mechanisms underlaid similar biogeographic patterns of surface bacterial and microeukaryotic communities in the tropical North Pacific Ocean.
海洋微生物群是全球生物地球化学循环的关键组成部分。然而，塑造它们的生物地理格局和生态过程仍然知之甚少，特别是在贫营养的海洋中。在这项研究中，我们使用高通量测序 16S 和 18S rRNA 基因来研究热带北太平洋表层水中细菌和微型真核生物群落的分布模式及其组装机制。细菌和微型真核生物群落都表现出相似的分布模式（即相似的距离衰减模式），并且根据其地理起源（即西热带北太平洋和中热带北太平洋）聚类，这一事实表明北太平洋的微生物群存在显著的生物地理格局。多样性指数（如物种丰富度、系统发育多样性和香农多样性指数）在区域之间也有显著差异。整个区域的空间和环境变量与细菌和微型真核生物的 alpha 和 beta 多样性之间的相关性通常相似。生态过程的相对重要性在细菌和微型真核生物之间存在差异：生态漂移是解释细菌群落结构的主要机制；异质选择、扩散限制和生态漂移共同解释了微型真核生物群落的大部分周转率。细菌和微型真核生物是海洋中极其多样化的群体，它们调节元素循环和能量流动。海洋微生物生态学的研究从基因组测序和理论微生物生态学的快速发展中受益匪浅。然而，贫营养海洋中海洋细菌和微型真核生物的空间分布以及决定其分布模式的组装机制的性质仍知之甚少。在这项研究中，我们使用高通量测序方法来确定贫营养、热带海洋中细菌和微型真核生物的分布模式和生态过程。我们的研究表明，在热带北太平洋，表面细菌和微型真核生物群落的相似生物地理格局背后存在着截然不同的群落组装机制。
