Liu Han, Guo Xianwu, Gooneratne Ravi, Lai Ruifang, Zeng Cong, Zhan Fanbin, Wang Weimin
College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan 430070, P. R. China.
Laboratorio de Biotecnología Genómica, Centro de Biotecnología Genómica, Instituto Politécnico Nacional, Boulevard del Maestro esquina Elías Piña, Colonia Narciso Mendoza, Ciudad Reynosa, 88710, Tamaulipas, Mexico.
Sci Rep. 2016 Apr 13;6:24340. doi: 10.1038/srep24340.
Vertebrate gut microbiome often underpins the metabolic capability and provides many beneficial effects on their hosts. However, little was known about how host trophic level influences fish gut microbiota and metabolic activity. In this study, more than 985,000 quality-filtered sequences from 24 16S rRNA libraries were obtained and the results revealed distinct compositions and diversities of gut microbiota in four trophic categories. PCoA test showed that gut bacterial communities of carnivorous and herbivorous fishes formed distinctly different clusters in PCoA space. Although fish in different trophic levels shared a large size of OTUs comprising a core microbiota community, at the genus level a strong distinction existed. Cellulose-degrading bacteria Clostridium, Citrobacter and Leptotrichia were dominant in the herbivorous, while Cetobacterium and protease-producing bacteria Halomonas were dominant in the carnivorous. PICRUSt predictions of metagenome function revealed that fishes in different trophic levels affected the metabolic capacity of their gut microbiota. Moreover, cellulase and amylase activities in herbivorous fishes were significantly higher than in the carnivorous, while trypsin activity in the carnivorous was much higher than in the herbivorous. These results indicated that host trophic level influenced the structure and composition of gut microbiota, metabolic capacity and gut content enzyme activity.
脊椎动物的肠道微生物群通常是其代谢能力的基础，并对宿主产生许多有益影响。然而，关于宿主营养级如何影响鱼类肠道微生物群和代谢活性，人们知之甚少。在本研究中，从24个16S rRNA文库中获得了超过985,000条经过质量过滤的序列，结果揭示了四个营养类别中肠道微生物群的不同组成和多样性。主坐标分析（PCoA）测试表明，肉食性和草食性鱼类的肠道细菌群落在PCoA空间中形成了明显不同的聚类。尽管不同营养级的鱼类共享大量构成核心微生物群落的操作分类单元（OTU），但在属水平上存在明显差异。宏基因组功能的PICRUSt预测表明，不同营养级的鱼类会影响其肠道微生物群的代谢能力。此外，草食性鱼类的纤维素酶和淀粉酶活性显著高于肉食性鱼类，而肉食性鱼类的胰蛋白酶活性远高于草食性鱼类。这些结果表明，宿主营养级会影响肠道微生物群的结构和组成、代谢能力以及肠道内容物酶活性。
