生物制品公司周边环境中2株大肠杆菌噬菌体的分离鉴定
Isolation and Characterization of Two Escherichia coli Specific Bacteriophages from Surrounding Environment of Biological Products Company

为了检测生物制品公司周边环境中噬菌体的种类及含量,以大肠杆菌(CMCC44102)为宿主菌,对生物制品公司污水处理厂污水样本中的噬菌体进行了分离纯化,并对纯化样本的一般生物学特性进行了鉴定。实验分离获得了2株噬菌体ΦL和ΦS,ΦL噬菌斑直径为1~2 mm,ΦS噬菌斑直径为0.1~0.3 mm。2株噬菌体在电镜下形态极为相似,均可见明显头部和尾部结构,头部呈正多面体,直径约为33 nm;尾部较短,长约21 nm,可见爪刺样结构。ΦL与ΦS的一般生物学特性大多相似,前者效价为2.129×1010 PFU/mL,后者为2.5645×1010 PFU/mL;2株噬菌体的最佳感染复数均为10;在37 ℃及以下温度均具有良好的稳定性;且均对宿主菌,即大肠杆菌(CMCC44102)具有高度属特异性。一步生长曲线结果表明,ΦL的潜伏期和爆发期均显著短于ΦS,说明ΦL生长能力强于ΦS。上述结果表明,生物制品公司周边环境中存在大量噬菌体,并对一些重要工程菌具有高度特异性,应高度关注并防止其对生物产品质量产生影响。
In order to investigate the bacteriophages existed in surrounding environment of biological products company,two E.coli CMCC44102 specific bacteriophages,named ΦL and ΦS,were isolated from sewage and characterized.The plaque of ΦL was larger (1-2 mm) and the plaque of ΦS was smaller (0.1-0.3 mm).Both ΦL and ΦS had similar biological characteristics,such as similar structures under TEM,which consist of a head (33 nm in dia.) and a short tail (21 nm in length),similar titers (ΦL,2.129×1010 PFU/mL,and ΦS,2.5645×1010 PFU/mL),the same optimal multiplicity of infection (both were 10),and the same host range.The only difference between ΦL and ΦS was that ΦL showed a much faster growth rate than ΦS did in one-step growth curve.All these results demonstrated that bacteriophages specific to engineering bacteria could be found in surrounding environment of biological products company and might severely influence the quality of bioproducts,which deserves high attention.