基于宏基因组技术研究鲟几个重要发育时期肠道细菌群落结构

鲟是我国最重要的冷水养殖鱼类之一，也是贵州省养殖产量最高的冷水鱼品种。人工繁育过程中发现，在苗种培育阶段由于不能对所投喂人工饵料进行有效的消化吸收，苗种存活率普遍较低，已成为鲟养殖业的发展瓶颈。研究表明鱼类肠道菌群是鱼类消化道的重要组成部分，对鱼类的生长、发育、生理和免疫都发挥重要作用。因此，本项目以养殖鲟肠道为研究对象，采用宏基因组技术，分析鉴定商品鲟肠道的细菌群落结构。针对苗种培育阶段仔鱼开口摄食和幼鱼转食两个关键时期，研究开口前后细菌的群落结构和变化情况，分析细菌的定植过程；通过对比转食过程中饲喂不同饵料的肠道细菌的差异，解析肠道细菌群落结构对食物的适应性变化过程，分析消化相关细菌。对益生菌进行分离、评价，明确其在不同温度条件下的生物活性。本项目为解决鲟养殖产业中的实际问题提供技术指导，也为阐明细菌群落在鲟健康、营养与免疫中的作用，及益生菌及饲料添加剂的开发提供理论依据。

Sturgeon is one of the most important cultured cold water fish in China, which also has the highest product in Guizhou Province. The fry survival rate was generally low in the stage of seedling cultivation without the effective digestion and absorption of the artificial bait in the process of artificial breeding, and had become bottleneck of sturgeon aquaculture development. Gut microbiota is an important component of the fish digestive tract, due to important roles in the growth, development, physiology and immunity of host. Therefore, in this study we take the intestinal tract of sturgeon as research object and adopt the metagenome technology. We identify the intestinal bacterial species of commercial sturgeon. Aiming at the key development stages of initial feeding and food conversion period, we study the community structure and change before and after the initial feeding, analyze the colonization process of the bacteria; by comparing the differences of intestinal bacteria feeding different baits in the food conversion period, disclose the changing process of bacterial community structure in the adaptation of food, and analyze the bacteria associated with digestion. We separate and identify the probiotics, and study the biological activity under different temperatures. The study will provide technical guidance to solve the practical problems in sturgeon farming industry, contribute to know the effect of bactiria on health, nutrition and immunity of sturgeon, and provide theory basis for the development of probiotics and feed supplement.