山东省德州市禹城市和湖南省长沙市望城区分别属于我国北方和南方地区, 环境和气候差异明显。本试验以禹城市和望城区两地的草鱼(Ctenopharyngodon idella)、鲫鱼(Carassius auratus)和鲤鱼(Cyprinus carpio)为研究对象, 对肠道中的菌群进行16s rRNA V4高变区扩增, 基于IonS5TM XL测序平台进行测序, 并对相关数据进行分析。结果表明, 在门水平上鲫鱼、鲤鱼、草鱼的肠道优势菌主要为变形菌门(Proteobacteria)、梭杆菌门(Fusobacteria)、硬壁菌门(Firmicutes), 拟杆菌门(Bacteroidetes), 各组中这四种菌门所占比之和均在80%以上; 基于Bray-Curtis距离值的秩次进行组间差异显著性检验, 山东草鱼组和湖南草鱼组比较中组间差异大于组内差异(R=0.307, P<0.05), 且线性判别分析显示湖南草鱼组的特征性菌群为弧菌属, 而山东草鱼组的为梭菌纲, 推测特征性菌群差异与环境的影响有关; 有害菌种的统计分析表明, 湖南鲫鱼组和鲤鱼组的嗜水气单胞菌属相对丰度明显高于对应的山东鲫鱼组和鲤鱼组, 山东草鱼组和鲤鱼组的弧菌属相对丰度高于对应的湖南草鱼组和鲤鱼组, 可能受外界环境的影响, 不同地区抵御外来有害细菌的能力也不一样。本研究对两地的淡水鱼类肠道微生物群落结构进行了比较和分析, 为进一步的鱼类发育研究奠定基础。

In order to investigate the differences of intestinal microflora of freshwater fishes in two regions of China, we chose grass crap(Ctenopharyngodon idella), crucian crap(Carassius auratus) and crap(Cyprinus carpio)from Yucheng city (in Shandong Province belonging to northern China) and Wangcheng District (in Hunan Province belonging to southern China) as the experimental objects. The intestinal contents of fishes were sequenced by 16S rRNA gene V4 hypervariable regions via S5TM XL platform and then the sequencing data were analyzed. The results revealed that the dominant intestinal bacteria of grass crap, crucian crap and crap were Proteobacteria, Fusobacteria, Firmicutes and Bacteroidetes at phylum category. The sum of the four kinds of bacteria in each group was more than 80%. Based on the rank of Bray-Curtis distance, the differences between groups were significant. Compared with crap group, the differences among groups were significantly greater than that within groups (R=0.307, P<0.05), speculating that the difference of characteristic flora is related to the influence of environment. LDA (linear discriminant analysis)analysis showed that the biomarker of Hunan crap group was Vibrio. Meanwhile, it was Clostridium in Shandong crap. The statistical analysis of harmful strains showed that the relative abundance of Aeromonas hydrophila in Hunan grass crap group and Hunan crucian crap group was significantly higher than that in Shandong groups, and the relative abundance of Vibrio in Shandong crap group and Shandong crucian crap group was significantly higher than that in Hunan groups. The ability of fishes in different areas to resist the invasion of foreign harmful bacteria will change with the environment. The comparison and analysis of the intestinal microbial community structure of freshwater fishes in the two areas are established for the further research of freshwater fish growth.