异育银鲫养殖环境典型病原微生物检测和细菌群落解析

Typical pathogenic microorganisms detection and bacterial community analysis of gibel carp(Carassius auratus gibelio) breeding environment

【背景】水产养殖病害是限制淡水渔业发展的一个重要因素,养殖环境的微生物状况与鱼类健康紧密相关,已引起人们广泛关注。【目的】阐明养殖水体和沉积物中病原微生物丰度和细菌群落多样性变化特征。【方法】利用荧光定量PCR方法和末端限制性片段长度多态性(Terminal restriction fragment length polymorphism,T-RFLP)技术,对异育银鲫养殖环境水体和沉积物中的典型病原微生物进行定量检测,以及细菌群落多样性分析。【结果】养殖过程中病原菌丰度呈现不同的变化趋势,嗜水气单胞菌(Aeromonas hydrophila)、温和气单胞菌(A. sobria)和维氏气单胞菌(A. veronii)与鲤疱疹病毒Ⅱ型丰度变化呈显著正相关。水体中病原菌丰度受pH、温度和溶解氧等环境因子的影响显著。T-RFLP分析表明沉积物样品较水体样品细菌群落组成复杂,并且沉积物细菌群落动态变化幅度高于水体。水体和沉积物中细菌T-RFs数量范围分别在11-29和20-32之间,Shannon-wiener指数在1.44-2.87和2.44-3.25之间。【结论】养殖水体中的病原菌丰度高于沉积物,而沉积物细菌群落丰富度和多样性高于水体。病原菌丰度和细菌群落结构变化与环境因子密切相关,明确养殖池塘环境中病原微生物的生态分布和丰度变化,将为指导养殖过程中病原性疾病发生早期预警提供理论依据。

[Background] Aquaculture diseases are a significant constraint in the development of freshwater fisheries, and the microbial status of aquaculture environment is closely related to the health of fishes, which has drawn extensive attention. [Objective] To elucidate the change characteristics of pathogen abundances and bacterial community diversity in aquaculture environment. [Methods] Real-time fluorescence quantitative PCR method and terminal restriction fragment length polymorphism(T-RFLP) technology were used to quantify typical pathogens in gibel carp breeding environment, and to analyze bacterial community diversity. [Results] Pathogen abundances in the process of breeding presented different change trend, the abundances of Aeromonas hydrophila, A. sobria and A. veronii were significantly positively related to Cyprinid herpesvirus Ⅱ. The abundance of pathogens in water was significantly affected by pH, temperature, dissolved oxygen and other environmental factors. T-RFLP analysis showed that the composition of bacterial community in sediment samples was more complex than that in water samples, and the dynamic change range of bacterial community in sediment was higher than that in water. The T-RFs in water and sediment ranged from 11 to 29 and 20 to 32, respectively, and Shannon-wiener index ranged from 1.44 to 2.87 and 2.44 to 3.25, respectively. [Conclusion] The abundances of pathogens in cultured waters were higher than that in sediments, and the relative abundance and diversity of bacterial community in sediments were higher than that in water. The changes of pathogen abundances and bacterial community structure are closely related to environmental factors, and it will provide theoretical data for guiding the early warning of pathogenic diseases in the breeding processes to clarify the ecological distribution and abundance changes of pathogenic microorganisms in the aquaculture pond.