Ferris J J, Clesceri L S
Appl Microbiol. 1971 Apr;21(4):633-8. doi: 10.1128/am.21.4.633-638.1971.
The mechanism by which the replicative cycle of T4r(+) phage is inhibited by certain nonhost bacterial systems was investigated. Some Bacillaceae, especially Bacillus subtilis, decreased the plaquing efficiency of this virus more than 95% within 24 hr of exposure. Sarcina lutea and Micrococcus sp. both failed to cause any significant change in the infectivity of T4r(+) phage. Preliminary investigations into the nature of the inhibitory substance(s) suggested that an extracellularly elicited protein was at least partially responsible for this effect. Further analysis has implicated subtilisin, an exoprotease from B. subtilis, as the cause of some, if not all, of the observed decrease in plaquing efficiency. Gel-filtration chromatography of control and treated (14)C-labeled T4r(+) phage showed a wide dispersal of phage-specific material of these particles after 24 hr of exposure to pure subtilisin or to expended medium exoprotease from B. subtilis. It was concluded that B. subtilis exoprotease is capable of chemically altering the structure of the phage capsid, thus causing a decrease in its plaquing efficiency.
研究了某些非宿主细菌系统抑制T4r(+)噬菌体复制周期的机制。一些芽孢杆菌科细菌，特别是枯草芽孢杆菌，在接触24小时内可使这种病毒的噬斑形成效率降低95%以上。藤黄八叠球菌和微球菌属均未引起T4r(+)噬菌体感染性的任何显著变化。对抑制物质性质的初步研究表明，一种细胞外诱导蛋白至少部分导致了这种效应。进一步分析表明，枯草芽孢杆菌的一种外蛋白酶——枯草杆菌蛋白酶，即使不是全部，也是观察到的噬斑形成效率下降的部分原因。对照和经处理的（14）C标记的T4r(+)噬菌体经凝胶过滤层析显示，在接触纯枯草杆菌蛋白酶或枯草芽孢杆菌分泌的培养基外蛋白酶24小时后，这些颗粒的噬菌体特异性物质广泛分散。得出的结论是，枯草芽孢杆菌外蛋白酶能够化学改变噬菌体衣壳的结构，从而导致其噬斑形成效率降低。
