不同生长速度的大黄鱼肠道菌群结构的差异

Differences in intestinal flora of cultured large yellow croaker Pseudosciaena crocea with different growth rates

为分析肠道菌群结构变化对大黄鱼Pseudosciaena crocea生长速度的影响,采用高通量测序的方法,对生长条件相同、生长速度不同的两组大黄鱼肠道菌群结构进行了研究。结果表明:生长缓慢组鱼肠道内菌群OTUs和菌群多样性指数Chao1显著高于生长正常组(P<0.05),但两组间Shannon指数差异不显著(P>0.05);变形菌门Proteobacteria、厚壁菌门Firmicutes、梭杆菌门Fusobacteria和拟杆菌门Bacteroidetes为大黄鱼肠道内的优势菌群,其中变形菌门在两组鱼肠道内的相对丰度超过50%;两组大黄鱼肠道菌群结构变化主要集中在变形菌门、放线菌门Actinobacteria和蓝细菌门Cyanobacteria;科水平上的细菌相对丰度比较结果显示,变形菌门内的鞘脂单胞菌科Sphingomonadaceae、柄杆菌科Caulobacteraceae、丛毛单胞菌科Comamonadaceae、假单胞菌科Pseudomonadaceae和莫拉氏菌科Moraxellaceae在两组鱼肠道内的相对丰度差异显著(P<0.05),其中莫拉氏菌科在生长缓慢组鱼肠道内的含量显著高于生长正常组(P<0.05)。研究表明,不同生长速度的大黄鱼肠道菌群结构存在差异,生长缓慢组鱼肠道内菌群种类多于生长正常组;变形菌门内菌群变化与大黄鱼生长密切相关,莫拉氏菌科在鱼肠道内含量的变化可能是引起大黄鱼生长变慢的主要原因。

The intestinal microbiota was analyzed in large yellow croaker Pseudosciaena crocea cultured in the same conditions with different growth by the high-throughput sequencing to investigate the relationship between growth rate and intestinal flora. The results showed that there were significantly higher quantities of OTUs and Chao1 in the smaller-sized group than those in the larger-sized group（ P〈0. 05）,without significant differences in the quantities of Shannon between the two groups（ P〈0. 05）. The dominance of Proteobacteria,Firmicutes,Fusobacteria and Bacteroidete was shown in the microbiota,especially Proteobacteria with more than 50% abundances in both groups. The relative abundance in family level revealed that there were significant differences in Sphingomonadaceae,Caulobacteraceae,Comamonadaceae,Pseudomonadaceae and Moraxellaceae between the two groups（ P〈0. 05）,significantly higher relative abundance of Moraxellaceae in the smaller-sized group than that in the largersized one. The finding demonstrated that there were differences in intestinal flora in the fish with different growth rates. There was more species in intestinal bacteria in the smaller-sized group than that in the larger-sized group.The growth of the fish seems to be involved in changes in flora of Proteobacteria,and growth differences of the fish are suggested to be attributed to the variation in amount of intestinal Moraxellaceae.