肠道气泡堆积对银鲳肠道菌群结构的影响

Effect of the Intestinal Gas Bubble Accumulation on Intestinal Bacterial Communities in Silver Pomfret

为研究肠道气泡堆积对银鲳(Pampus argenteus)肠道菌群的影响,2019年3月于东海水产研究所福鼎研究中心采集了15尾肠道气泡堆积的银鲳为病鱼组,15尾健康银鲳为健康鱼组,并通过16S r DNA基因DNA高通量测序技术结合LEfSe分析方法,对两组样品间菌群结构和多样性进行对比分析。结果显示,病鱼组肠道菌群多样性与健康鱼组无显著差异(P>0.05),但病鱼组肠道菌群的均匀度和相对丰度都显著低于健康鱼组(P<0.05)。两组样品的优势菌群均为变形菌门(Proteobacteria),且相对丰度都较大(超过97%)。此外,利用LEfSe分析两组样品发现,病鱼组中如根瘤菌(Rhizobium)、栖热菌(Thermus)等好氧菌丰度显著高于健康鱼组,而不动肝菌(Acinetobacter)、微酸菌(Ilumatobacter)等显著低于健康鱼组,蓝细菌(Cyanobacteria)相对丰度显著高于健康鱼组。由此可以表明,肠道气泡堆积很可能会引发肠道菌群紊乱。

Silvery pomfret(Pampus argenteus)is a kind of valuable economic fish species and the intestinal gas bubble accumulation is an important factor that hinders its popularization.In order to evaluate the changes of the bacterial communities in Silvery pomfret’s intestine upon gas bubble accumulation occurrence,15 diseased fish were chosen as the diseased group and 15 healthy fish as the healthy group.The method of high-throughput sequencing of 16 S rDNA gene’s V3-V4 region was used to determine diversity and composition of bacterial communities in each of these samples.The comparison results of the Alpha diversity index showed that there was no significant difference in the Simpson index and the Shannon index between these two groups(P>0.05),but the Chao1 estimator and the ACE estimator in the diseased group are significantly lower than those of the healthy group(P<0.05)(Table 1).The analysis of the microbiota structure showed that the dominant bacterial groups were similar in the diseased and control groups,at the phylum level being Proteobacteria,and at the genus level being Sphingobium,Sphingomonas,Cupriavidus,Novo sphingobium and Acinetobacter(Table 2).From the above results,it can be concluded that the intestinal gas bubble accumulation reduces the richness and evenness of intestinal flora of Silvery pomfret,but does not affect its diversity.In addition,the two groups of samples were analyzed by LEfSe and the results showed that the relative abundance of aerobic bacteria such as agrobacterium bacteria,thermophilic bacteria,cyanobacteria,rhizobial bacteria in the diseased group was significantly higher than that of the healthy group,while the relative abundance of acinetobacter and microacidic bacteria was significantly lower than that of the healthy group(Fig.3 and Fig.4).From these results,it can be concluded that the intestinal gas bubble accumulation may cause intestinal flora disorder.