许氏平鲉仔鱼、稚鱼、幼鱼肠道微生物群结构特征

采集常规饲养的健康许氏平鲉1日龄仔鱼,9、20日龄稚鱼,54、95日龄幼鱼,运用Illumina MiSeq PE300平台,对其肠道微生物的16S rDNA V3~V4可变区进行高通量测序,共获得1039个运算分类单位、667个属。在丰度高于1%的菌属水平上,野生鱼肠道菌群丰度的平均值(86%)远高于幼鱼时期的平均值(73.5%)。不动杆菌属为仔鱼、稚鱼、幼鱼肠道中最优势菌属(丰度为26.2%~45.3%);短芽孢杆菌属次之。结合共有菌属分析获得11个核心菌群,芽孢杆菌属、短芽孢杆菌属、不动杆菌属、根瘤菌属等的丰度随仔鱼、稚鱼、幼鱼生长先升后降,均在54日龄时丰度最高;弧菌属则呈现相反的趋势(0.37%~12.41%),54日龄时丰度最低。仔鱼、稚鱼、幼鱼与野生个体肠道仅有14个共有菌属,短芽孢杆菌属、Massilia的最小丰度值分别是野生个体肠道中最大丰度值的9倍和32倍,差异明显。本研究揭示了许氏平鲉仔鱼、稚鱼、幼鱼肠道菌群结构特征及其发生、发育的过程,为苗种繁育阶段肠道生理健康调控提供理论依据。

Structural Characteristics of Intestinal Microbiota in Black Rockfish Sebastes schlegelii during Early Life Stage

V3 and V4 variable regions of 16 S rDNA of intestinal microbiota were sequenced in black rockfish Sebastes schlegelii larvae and juveniles with 1, 9, 20, 54 and 95 day after hatching(DAH) using Illumina MiSeq PE300 system. A total of 1039 operational taxonomic units(OTU) and 667 genera were obtained. At the genus level, there were higher microbial abundance and mean value(higher than 1%)(86%) in intestinal microbiota in wild fish than that in juvenile stage(73.5%), with the most abundances dominant genus of Acinetobacter(26.2%-45.3%), and followed by genus Brevibacillus. Meantime, the combined analysis of shared microflora revealed that there were 11 core microbiota. With growth of the larvae and juveniles, successional abundances for Bacillus, Brevibacillus, Acinetobacter and Rhizobium, belong to the core microbiota, were increased firstly and then declined rapidly, the maximal abundances of these four genera were all appeared on 54 DAH. However, Vibrio as one of the core microbiota, with abundances of 0.37%-12.41%, showed the opposite trend during the early life stage, with the minimal value on 54 DAH. There were only 14 shared genera in intestines between larvae and juveniles and wild ones, the minimum abundance of Brevibacillus and Massilia in intestine of larvae and juveniles being 9 times and 32 times as the maximum value of these two genera in wild fish, showing the obvious difference. The findings will provide the theoretical reference for the regulation of intestinal physiological health during the life stage.