一株弗氏链霉菌噬菌体的分离及其分子特性研究

Identification and Molecular Characterization of a Phage from Streptomyces fradiae

鉴定一株从泰乐菌素异常发酵液中分离出的烈性噬菌体SF1并研究其分子特性。采用双层平板法分离纯化弗氏链霉菌的噬菌体SF1,通过负染法电镜观察噬菌体SF1的大小和形态;测定噬菌体SF1对氯仿和异丙醇的敏感性分析其包膜结构;通过SDS-PAGE分析噬菌体的结构蛋白;提取噬菌体基因组DNA进行限制性片段长度多样性分析。噬菌体SF1的噬菌斑直径约11-15 mm,边缘整齐透明,为烈性噬菌体;SF1为长尾型,头部为多面体,直径约24-30 nm,尾长约52-64 nm,尾宽约为3-5 nm;对氯仿和异丙醇不敏感,无包膜;基因组为双链DNA,大小约为35 kb;至少含有14种相对分子量为14.8-59.5 k D的结构蛋白。

It was to identify and explore the molecular characterization of a phage SF1, which was isolated from Streptomyces fradiae fermentation hroth during the failed industrial production of tylosin. Phage SF1 was characterized by observing the shape of plaque, titering on double-layer agar culture plate. The morphology of SF1 was observed by the electron microscopic observation after negative staining. The sensitivity of the phage to chloroform and isopropyl alcohol was tested to detect its envelope. The structural proteins analysis of phage SF1 was carried out by SDS-PAGE. Restriction fragment length polymorphism （ RFLP ） analysis of genomie DNA was further performed to characterize the phage. Results showed that the plaque （ 11-15 mm in diameter ） is neat and transparent. SF1 has a polyhedral head （ about 24-30 nm in diameter ） and a long tail （ about 52-64 nm long and 3-5 nm wide ） . It is insensitive to chloroform and isopropyl alcohol. The genome of SF1 consists of double-stranded DNA and is approximately 35 kb. Capsid protein analysis shows a higher level of 14 major protein bands ranging from 14.8-59.5 kD, which is presumed to be the structural proteins of SF1.