Institute of Biological and Environmental Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen, AB24 2TZ, UK.
Sci Rep. 2017 Oct 24;7(1):13877. doi: 10.1038/s41598-017-13249-8.
Atlantic salmon undergo dramatic physiological changes as they migrate from freshwater to the marine environment. Osmoregulatory adaptation is the most crucial change, necessitating functional adaptations of the gills, kidney and intestine. Additionally, novel pathogens, microbes and dietary items are encountered in the saltwater environment, which suggests major changes in the intestinal microbiota following movement to saltwater. Here we compared the intestinal microbiota harboured in the distal digesta of Atlantic salmon freshwater fish (FW) kept in a commercial Scottish freshwater hatchery with that of their full-siblings after seawater acclimatisation (SW) by a 16S rRNA (V3-V4) high-throughput sequencing approach. Alpha- and beta-diversity were found significantly higher in FW compared to SW, both in terms of richness and diversity. Metastats analysis identified a higher number of Operational Taxonomic Units (OTUs) unique to FW compared to SW, with an additional 238 OTUs found at significantly different abundance. A core microbiota of 19 OTUs was identified in 100% of all fish, which indicates that certain microbes are maintained to fulfil minimal functions within the gut. Furthermore we show that the uniqueness of the respective microbial profiles can be correlated with significant differences in KEGG pathways including lipid and amino acid metabolism.
当大西洋鲑从淡水迁移到海洋环境时，它们会经历剧烈的生理变化。渗透调节适应是最重要的变化，需要鳃、肾脏和肠道的功能适应。此外，在咸水环境中会遇到新的病原体、微生物和食物，这表明在迁移到咸水后，肠道微生物群会发生重大变化。在这里，我们通过 16S rRNA（V3-V4）高通量测序方法比较了在苏格兰商业淡水孵化场中饲养的大西洋鲑淡水鱼（FW）的远端消化物中携带的肠道微生物群，以及它们经过海水驯化（SW）后的全同胞的肠道微生物群。与 SW 相比，FW 的 alpha 和 beta 多样性在丰富度和多样性方面都显著更高。Metastats 分析确定了 FW 中比 SW 更多的独特操作分类单元（OTUs），其中有 238 个 OTUs 的丰度存在显著差异。在所有鱼类中都鉴定出了一个由 19 个 OTUs 组成的核心微生物群，这表明某些微生物被维持以在肠道中发挥最小功能。此外，我们还表明，各自微生物谱的独特性可以与 KEGG 途径的显著差异相关，包括脂质和氨基酸代谢。
