【作者】 万方林； 王颖； 张锦华； 周秋白；

【Author】 WAN Fanglin;WANG Ying;ZHANG Jinhua;ZHOU Qiubai;Jiangxi Agricultural University;

【机构】 江西农业大学动物科学技术学院；

【摘要】 越来越多的研究证明索氏鲸杆菌作为大多数淡水鱼类肠道的土著菌,其在鱼类健康中扮演着重要的角色。在前期的对健康与上草黄鳝肠道菌群差异研究发现,鲸杆菌是二者的主要差异优势菌属。本研究在此基础上,采用厌氧培养、纯化与分子鉴定相结合的方法,从健康黄鳝肠道中获得3株索氏鲸杆菌(C4、C24、C29)。体外表型试验表明三株菌在5%羊血平板上表现γ溶血型(无溶血),对多种抗生素敏感,在生长过程中产生酸性代谢产物。基因组分析显示C4与C24聚为一支,C29独立成支,三株菌功能基因组成相似,其中碳水化合物代谢相关基因最为丰富,且均携带厌氧条件下合成钴胺素的完整通路基因。体外代谢表型显示菌株C29具有合成(胞内)和释放(胞外)VB12的能力。本研究旨在促进潜在益生菌索氏鲸杆菌在黄鳝养殖中的开发与应用。更多还原

【Abstract】 An increasing number of studies have demonstrated that Cetobacterium somerae, a predominant indigenous bacterium in the intestines of most freshwater fish, plays an important role in maintaining host health. Based on previous research comparing the intestinal microbiota between healthy and diseased Monopterus albus, three C. somerae strains(C4, C24, and C29) were isolated from the intestines of healthy individuals using a combination of anaerobic cultivation, purification,and molecular identification. In vitro phenotypic characterization revealed that all strains exhibited aγ-hemolytic(non-hemolytic) pattern on 5% sheep blood agar, were sensitive to multiple antibiotics, and produced acidic metabolites during growth. Genomic analysis showed that C4 and C24 clustered together while C29 formed an independent branch. The three strains shared similar functional gene profiles, with carbohydrate metabolism genes being the most abundant, and all harbored a complete anaerobic cobalamin(vitamin B??) biosynthesis pathway. Metabolic assays further demonstrated that strain C29 possessed the ability to synthesize vitamin B?? intracellularly and release it extracellularly.This study provides a theoretical basis for the screening and application of C. somerae as a probiotic candidate in M. albus aquaculture.更多还原