Department of Molecular and Cell Biology, School of Natural Sciences, University of California Merced, Merced, CA, United States of America.
Quantitative and Systems Biology Graduate Program, University of California Merced, Merced, CA, United States of America.
PLoS One. 2019 Feb 14;14(2):e0212355. doi: 10.1371/journal.pone.0212355. eCollection 2019.
Microbial communities control numerous biogeochemical processes critical for ecosystem function and health. Most analyses of coastal microbial communities focus on the characterization of bacteria present in either sediment or seawater, with fewer studies characterizing both sediment and seawater together at a given site, and even fewer studies including information about non-bacterial microbial communities. As a result, knowledge about the ecological patterns of microbial biodiversity across domains and habitats in coastal communities is limited-despite the fact that archaea, bacteria, and microbial eukaryotes are present and known to interact in coastal habitats. To better understand microbial biodiversity patterns in coastal ecosystems, we characterized sediment and seawater microbial communities for three sites along the coastline of Puerto Nuevo, Baja California, Mexico using both 16S and 18S rRNA gene amplicon sequencing. We found that sediment hosted approximately 500-fold more operational taxonomic units (OTUs) for bacteria, archaea, and microbial eukaryotes than seawater (p < 0.001). Distinct phyla were found in sediment versus seawater samples. Of the top ten most abundant classes, Cytophagia (bacterial) and Chromadorea (eukaryal) were specific to the sediment environment, whereas Cyanobacteria and Bacteroidia (bacterial) and Chlorophyceae (eukaryal) were specific to the seawater environment. A total of 47 unique genera were observed to comprise the core taxa community across environment types and sites. No archaeal taxa were observed as part of either the abundant or core taxa. No significant differences were observed for sediment community composition across domains or between sites. For seawater, the bacterial and archaeal community composition was statistically different for the Major Outlet site (p < 0.05), the site closest to a residential area, and the eukaryal community composition was statistically different between all sites (p < 0.05). Our findings highlight the distinct patterns and spatial heterogeneity in microbial communities of a coastal region in Baja California, Mexico.
微生物群落控制着许多对生态系统功能和健康至关重要的生物地球化学过程。大多数关于沿海微生物群落的分析都集中于描述存在于沉积物或海水中的细菌，只有少数研究同时描述了给定地点的沉积物和海水，而包括非细菌微生物群落信息的研究则更少。因此，尽管古菌、细菌和微生物真核生物在沿海栖息地存在并已知相互作用，但关于沿海群落中微生物生物多样性的生态模式的知识是有限的。为了更好地了解沿海生态系统中的微生物生物多样性模式，我们使用 16S 和 18S rRNA 基因扩增子测序技术，对墨西哥下加利福尼亚州巴哈半岛新普雷韦扎角的三个沿海地点的沉积物和海水微生物群落进行了描述。我们发现，沉积物中细菌、古菌和微生物真核生物的操作分类单元（OTUs）数量大约是海水的 500 倍（p < 0.001）。沉积物和海水样本中发现了不同的门。在前十名最丰富的类群中，Cytophagia（细菌）和 Chromadorea（真核生物）是沉积物环境特有的，而 Cyanobacteria 和 Bacteroidia（细菌）和 Chlorophyceae（真核生物）是海水环境特有的。共有 47 个独特的属被观察到构成了跨环境类型和地点的核心分类群社区。在丰富度或核心分类群中没有观察到古菌类群。沉积物群落组成在各域或各地点之间没有观察到显著差异。对于海水，主要出水口（靠近居民区的地点）的细菌和古菌群落组成在统计学上有显著差异（p < 0.05），而所有地点的真核生物群落组成在统计学上也有显著差异（p < 0.05）。我们的研究结果突出了墨西哥下加利福尼亚沿海地区微生物群落的独特模式和空间异质性。
