【摘要】 从土壤微生物中筛选得到一株产神经节苷脂内切糖苷酶的菌株YW2 1 1 2 ,该酶能特异性水解神经节苷脂中连接神经酰胺和寡糖链之间的糖苷键 ,是研究神经节苷脂结构与功能的重要工具酶。对分离菌株YW2 1 1 2进行了形态、生理生化鉴定及 1 6SrDNA序列分析。菌株YW2 1 1 2为细菌 ,革兰氏染色阴性 ,直杆状 ,鞭毛周生 ,菌体大小为 ( 0 6μm～ 1 μm)× ( 1 μm～3μm) ,V -P实验阳性 ,甲基红阴性 ,利用葡萄糖产酸产气。以 1 6SrDNA同源性为基础构建了包括 1 1株相关种属细菌在内的系统发育树 ,在系统发育树中 ,分离菌株YW2 1 1 2与Enter obactercloacae在同一分支 ,二者的序列相似性为 98 6% ,结合形态和生理生化鉴定 ,将其鉴定为阴沟肠杆菌 (Enterobactercloacae)。更多还原

【Abstract】 A bacterial isolate YW2112 producing endoglycoceramidase was isolated from soil. The enzyme catalyzed the hydrolysis of the linkage between oligosaccharides and ceramides of gangliosides. It was a very important analytical tool for the elucidation of biological functions and structures of gangliosides. The isolated strain YW2112 was identified by 16S rDNA sequence, morphological,biochemical and physiological identification. The cells of the strain YW2112 were straight rods that were 0 6μm～1 0μm wide×1 0μm～3 0μm long, Gram negative, peritrichous flagella, V-P positive, Methyl red negative. D glucose and other carbohydrates were catabolized with the production of gas and acid. A phylogenetic tree was constructed by comparing with the published 16S rDNA sequences of the relative bacteria species. In the phylogenetic tree YW2112, Enterobacter cloacae,Enterobacter dissolvens and Klebsiella pneumoni constitute a branch and Enterobacter cloacae was the closest relative with 98 6% sequence similarity. The results indicated that strain YW2112 was belong to Enterobacter cloacae.更多还原