鲟鳇鱼网箱养殖环境微生物菌群结构及潜在病原菌分析

为探究鲟鳇鱼网箱养殖环境中的细菌群落结构组成和潜在致病菌的种类与数量, 文章用高通量测序对中华鲟Acipenser sinensis、施氏鲟Acipenser schrenckii、达氏鳇Huso dauricus、大杂交鲟A. schrenckii♂×H. dauricus♀等网箱养殖水体的细菌群落结构特征和潜在病原菌属进行分析, 同时应用实时荧光定量PCR方法对鲟鳇鱼养殖水体中的典型病原菌种进行定量检测。研究结果表明, 在同一水域同一管理条件下, 不同品种鲟鳇鱼网箱养殖水体中细菌群落结构组成相似度高, 优势菌门由Proteobacteria、Actinobacteria、Bacteroidetes、Verrucomicrobia和Planctomycetes组成, 占到所有样品序列总数的88.81%—93.94%; 在属水平上, 各样品未分类的细菌(unclassified)占比较大, 共发现鲟鳇鱼潜在致病细菌菌属7个: Aeromonas、Acinetobacter、Chryseobacterium、Edwardsiella、Flavobacterium、Pseudomonas和Vibrio。实时荧光定量PCR结果显示, 养殖水体中鲟鳇鱼病害常见的病原菌种Aeromonas hydrophila的丰度最高, 丰度值为(7406±1892) copies/mL; 其次为Flavobacterium columnar(4889±1649) copies/mL]和Pseudomonas fluorescens(3259±1117) copies/mL]。研究结果为该区域的鲟鳇鱼集约化养殖及疾病防控提供科学依据。

ANALYSIS OF MICROBIAL COMMUNITIES STRUCTURE AND POTENTIAL PATHOGENS IN STURGEON CAGE CULTURE ENVIRONMENT

Sturgeon is rare ancient and diadromous fish. The microbial status of aquaculture environment is closely related to the health of fishes, which has drawn extensive attention. Here, high-throughput sequencing technology was used to determine the community composition and complexity of the microbiota in A. sinensis, A. schrenckii, H. dauricus, and hybrid sturgeon (A. schrenckii ♂×H. dauricus ♀) breeding environment farmed in Chinese sturgeon conservation center. The potential pathogens of their microbial communities were assessed by Real-time fluorescence quantitative PCR technology (RT-PCR). The results demonstrated that the microbiota in cage culture water were dominated by bacteria in the phyla Proteobacteria, Actinobacteria, Bacteroidetes, Verrucomicrobia and Planctomycetes, which accounted for 88.81%—93.94% of the sequenced reads in all samples. At the genus level, unclassified genera represented a considerable proportion in all of the experimental samples. Statistical analyses revealed that the diversity of microbial community among the groups did not reach the significant level, and the similarity of the microbial communities was high. The potential pathogenic genera in the culture water were Aeromonas, Acinetobacter, Chryseobacterium, Edwardsiella, Flavobacterium, Pseudomonas and Vibrio. The RT-PCR analyses indicated that A. hydrophila (7406±1892) copies/mL] was the most abundant pathogen in sturgeon cage culture water, followed by F. columnar (4889±1649) copies/mL] and P. fluorescens (3259±1117) copies/mL]. Our results will be the basis for guiding healthy aquaculture of sturgeon and the early warning of pathogenic diseases in the breeding processes.