Department of Applied Animal Science, College of Animal Life Sciences, Kangwon National University, Chuncheon, 24341, Kangwon-do, Republic of Korea.
Department of Animal Life Science, College of Animal Life Sciences, Kangwon National University, Chuncheon, 24341, Republic of Korea.
Curr Microbiol. 2021 May;78(5):1798-1806. doi: 10.1007/s00284-021-02440-w. Epub 2021 Mar 18.
Freshwater smelt (Hypomesus nipponensis) is a planktivorous fish found in the river of South Korea, Japan, China, and Russia. Because of its specific characteristics living in the cold temperature, this species is economically valuable in the various countries that held winter festival. The body size of the smelt is too small, so people consumed raw smelt during the winter festival sometimes. However, the microbial studies of smelt are nonexistent. Here, we characterized and compared the bacterial communities in the gut and skin of freshwater smelts. We amplified, sequenced, and analyzed the V4 regions of bacterial 16S rRNA genes from freshwater smelts. The microbial diversity in the skin (375 OTUs) was much greater than that in the gut (250 OTUs). At the phylum level, Proteobacteria (gut: 51.5%; skin: 52.9%), Firmicutes (gut: 30.6%; skin: 25.4%), Bacteroidetes (gut: 7.7%; skin: 14.7%), and Actinobacteria (gut: 5.2%; skin: 3.8%) were predominant in both organs. At the genus level, Sphingomonas (gut: 24.9%; skin: 4.4%, P < 0.01) was more abundant in the gut, whereas Acinetobacter (gut: 0.8%; skin: 11.8%, P = 0.02) and Pseudomonas (gut: 0.3%; skin: 2.1%, P = 0.01) were more abundant in the skin. Both beneficial (Lactobacillus) and harmful (Staphylococcus and Streptococcus) bacteria were detected in both organs, even under freshwater conditions. These results revealed that smelts have their own unique microbial communities in the gut and skin. Our findings broaden the understanding of planktivorous freshwater fish microbiomes and provide new insights into fish microbiomes for ensuring food safety.
日本七鳃鳗是一种生活在韩国、日本、中国和俄罗斯河流中的洄游性肉食性鱼类。由于其生活在低温下的特殊特性，这种鱼类在举办冬季节日的各个国家都具有经济价值。七鳃鳗的体型很小，因此人们有时会在冬季节日期间生吃七鳃鳗。然而，目前对于七鳃鳗的微生物研究还很少。在这里，我们对淡水七鳃鳗的肠道和皮肤中的细菌群落进行了特征描述和比较。我们扩增、测序并分析了淡水七鳃鳗肠道和皮肤中细菌 16S rRNA 基因的 V4 区。皮肤（375 个 OTUs）中的微生物多样性远大于肠道（250 个 OTUs）。在门水平上，变形菌门（gut: 51.5%；skin: 52.9%）、厚壁菌门（gut: 30.6%；skin: 25.4%）、拟杆菌门（gut: 7.7%；skin: 14.7%）和放线菌门（gut: 5.2%；skin: 3.8%）在这两个器官中都占主导地位。在属水平上，鞘氨醇单胞菌属（gut: 24.9%；skin: 4.4%，P < 0.01）在肠道中更为丰富，而不动杆菌属（gut: 0.8%；skin: 11.8%，P = 0.02）和假单胞菌属（gut: 0.3%；skin: 2.1%，P = 0.01）在皮肤中更为丰富。在这两种器官中，甚至在淡水条件下，都检测到了有益菌（乳杆菌）和有害菌（葡萄球菌和链球菌）。这些结果表明，七鳃鳗在肠道和皮肤中具有独特的微生物群落。我们的研究结果拓宽了对洄游性肉食性淡水鱼类微生物组的认识，并为确保食品安全提供了鱼类微生物组的新见解。
