Orrego C, Kerjan P, Manca de Nadra M C, Szulmajster J
J Bacteriol. 1973 Nov;116(2):636-47. doi: 10.1128/jb.116.2.636-647.1973.
Partially synchronized cultures of a Bacillus subtilis thermosensitive sporulation mutant (ts-4) and the 168 try(-)try(-) (168tt) parental strain were infected with the virulent phage phie at various times during their growth cycle at 30 and 42 C (permissive and restrictive temperatures, respectively). It was shown that at the restrictive temperature the burst size in the parental strain was two- to threefold lower than in the ts-4 mutant. No such difference was observed at the permissive temperature. However, the time at which this difference was observed excludes a correlation between the burst size and initiation of the sporulation process. It was further found that the capacity to transcribe in vitro phage phie deoxyribonucleic acid by partially purified ribonucleic acid (RNA) polymerase from both strains decreased sharply if the source of enzyme was sporulating cells instead of vegetative ones. However, a similar decrease, although to a lesser extent, was observed with the RNA polymerase isolated from stationary-phase cells of the ts-4 mutant grown at the nonpermissive temperature, or with the enzyme derived from several other zero-stage sporulation mutants. At no time was a structural modification in the beta subunits of the RNA polymerase observed during growth of the sporulating bacteria. We have also shown that, in addition to the relatively low specific activity of the RNA polymerase, the level of the intracellular protease activity is about 15-fold lower in the ts-4 mutant grown at the restrictive temperature than that of the parental strain grown at the same temperature. At the permissive temperature no such difference was observed between these two strains. However, the present data do not allow us to establish a correlation among the low content of intracellular protease, the weak specific activity of the RNA polymerase, and the loss of the sporulation capacity in the ts-4 mutant grown at the restrictive temperature.
在30℃和42℃（分别为允许温度和限制温度）下，将芽孢杆菌属枯草芽孢杆菌热敏性芽孢形成突变体（ts - 4）和168 try(-)try(-)（168tt）亲本菌株的部分同步培养物在其生长周期的不同时间用烈性噬菌体phie进行感染。结果表明，在限制温度下，亲本菌株的裂解量比ts - 4突变体低两到三倍。在允许温度下未观察到这种差异。然而，观察到这种差异的时间排除了裂解量与芽孢形成过程起始之间的相关性。进一步发现，如果酶的来源是正在形成芽孢的细胞而非营养细胞，那么用来自这两种菌株的部分纯化的核糖核酸（RNA）聚合酶在体外转录噬菌体phie脱氧核糖核酸的能力会急剧下降。不过，从在非允许温度下生长的ts - 4突变体的稳定期细胞中分离出的RNA聚合酶，或者从其他几个零阶段芽孢形成突变体衍生的酶，也观察到了类似程度较轻的下降。在芽孢形成细菌生长过程中，未观察到RNA聚合酶β亚基的结构修饰。我们还表明，除了RNA聚合酶相对较低的比活性外，在限制温度下生长的ts - 4突变体中细胞内蛋白酶活性水平比在相同温度下生长的亲本菌株低约15倍。在允许温度下，这两种菌株之间未观察到这种差异。然而，目前的数据不允许我们确定在限制温度下生长的ts - 4突变体中细胞内蛋白酶含量低、RNA聚合酶比活性弱与芽孢形成能力丧失之间的相关性。
