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目的通过分离鉴定大肠埃希菌噬菌体,研究其生物学特性。方法利用噬菌斑法从环境污水中分离和鉴定大肠埃希菌噬菌体,采用负染法电镜观察噬菌体的形态和大小;提取噬菌体的基因组并进行酶切电泳分析,测定噬菌体感染复数并观察其一步生长曲线。结果通过噬菌斑法分离出9株大肠埃希菌噬菌体。电镜显示,噬菌体头部呈立体对称,有一长尾。琼脂糖凝胶电泳显示,噬菌体基因组大小约30kb。生长曲线表明噬菌体感染宿主菌的潜伏期为23min,爆发时间为39min,裂解量为78。结论9株大肠埃希菌噬菌体中有6株具有较广的噬菌谱,潜伏期短,裂解量明显,为深入研究大肠埃希菌噬菌体的生物学特性及其功能提供了依据。
Objective To isolate and identify Escherichia coli phage and study its biological characteristics. Methods The phage of Escherichia coli was isolated and identified from environmental sewage by plaque assay. The morphology and size of phage were observed by negative staining electron microscopy. The phage genome was extracted and analyzed by restriction enzyme digestion. The number of phage infection was determined and observed for one step Growth curve. Results Nine strains of Escherichia coli were isolated by plaque assay. Electron microscopy showed phage head was three-dimensional symmetry, there is a long tail. Agarose gel electrophoresis showed that the size of the phage genome was about 30 kb. The growth curves showed that the phage-infected host strain had an incubation period of 23 min, an eruption time of 39 min and a lysed amount of 78. Conclusion Six of the nine strains of Escherichia coli have a broad spectrum of phage with short incubation period and obvious cleavage. These results provide the basis for further study on the biological characteristics and function of Escherichia coli phage.