中文摘要：

【目的】对来自中国典型培养物保藏中心（CCTCC）的39株枯草芽孢杆菌中的PBSX类缺陷性原噬菌体进行普遍性调查。【方法】对实验菌株进行丝裂霉素C（MMC）诱导,得到诱导后的裂解液上清。通过裂解液上清中13 kb DNA片段的存在情况,及其对PBSX敏感菌Bacillus subtilis W23的攻击作用,判断该菌株是否携带PBSX类缺陷性原噬菌体。同时利用透射电镜检测裂解液上清中噬菌体状颗粒。【结果】39株检测菌株中,24株菌裂解液上清含有13 kb DNA片段,对W23也具有较强的攻击能力,为PBSX溶源菌;1株菌裂解液上清中含有13 kb DNA片段,但不能攻击W23;5株菌裂解液上清中不含13 kb DNA片段,但依然对W23具有一定的攻击能力;另外9株裂解液上清中不含13 kb DNA片段,对W23也不具备攻击能力,其中3株菌株裂解液上清中能检测到大小不同于PBSX的噬菌体状颗粒。【结论】39株检测菌株中,携带有PBSX的菌株占61.5%的比重,具有一定普遍性;而工业菌株以及分离自神农架土壤中的野生菌株中含有不同于PBSX的多种噬菌体状颗粒。本文结果为进一步揭示PBSX对于宿主菌的作用提供了更多的理论依据。

英文摘要：

[Objective] To investigate PBSX-like defective prophages resident in 39 Bacillus subtilis strains preserved in China Center for Type Culture Colletion（CCTCC）. [Methods] B. subtilis strains were induced with mitomycin C, yielding cell lysate supernatants. Agarose gel electrophoresis was used to detect the existence of 13 kb DNA fragments in cell lysate supernatants. Cell lysate supernatants were mixed with PBSX-sensitive strain, B. subtilis W23 to determine the killing activity against W23. Phage-like particles in the cell lysate supernatants were examined with transmission electron microscopy. [Results] Cell lysate supernatants of 24 strains were detected to have 13 kb DNA fragments, and had killing activity against W23. They were defined as PBSX lysogenic bacteria. 1 strain＇s lysate supernatants possessed 13 kb DNA fragments, but had no killing activity against W23. 5 strains＇ lysate supernatants displayed killing activity against W23 although 13 kb DNA fragments were not detected in them. 9 strains＇ lysate supernatants did not have 13 kb DNA fragments, as well as had no killing activity against W23. Among the 9 strains, 3 strains＇ lysate supernatants were detected to have phage-like particles distinguished with PBSX. [Conclusion] Among the 39 B. subtilis strains, 61.5% are PBSX lysogenic bacteria. Industrial strains and wild strains isolated from soil collected from Shennongjia harbor various phage-like particles distinguished from PBSX. Results in this paper provide more theory evidences for further uncovering the function of PBSX on host bacteria.