Pooley H M
J Bacteriol. 1976 Mar;125(3):1139-47. doi: 10.1128/jb.125.3.1139-1147.1976.
When soluble autolytic activity was added to growing cultures of a mutant possessing a reduced rate of cell wall turnover, there was a delay of more than one generation before solubilization of new cell wall began, in contrast to the immediate increase in the rate of solubilization of old cell wall. A similar delay was found before turnover of new cell wall occurred in the parent, in agreement with a previous report (Mauck et al., 1971). When sodium lauryl sulfate-inactivated cell walls were prepared, the great bulk of the wall formed a uniformly susceptible substrate to added autolytic activity. The immediate solubilization of new wall eliminates insusceptibility to autolytic enzyme as an explanation for the failure to be turned over. There were, however, major differences in the rate of solubilization of wall of different ages. During solubilization of the initial 30% of the cell wall preparation, wall two generations old was solubilized at least seven times faster than wall one-half a generation old. This result is interpreted in terms of differences in accessibility. The cell wall is seen as consisting of a series of layers, the age of which increases with the distance from the membrane, such that wall newly synthesized on the membrane passes out through the thickness of the cell wall layer during subsequent growth and only becomes susceptible to turnover as it reaches the outer surface, largely in the form of a layer, more than one generation after incorporation.
当将可溶性自溶活性添加到细胞壁更新速率降低的突变体的生长培养物中时，与旧细胞壁溶解速率立即增加形成对比的是，新细胞壁开始溶解前有超过一代的延迟。在亲代中，新细胞壁更新发生之前也发现了类似的延迟，这与之前的一份报告（Mauck等人，1971年）一致。当制备月桂基硫酸钠灭活的细胞壁时，大部分细胞壁形成了对添加的自溶活性均匀敏感的底物。新细胞壁的立即溶解排除了对自溶酶不敏感是其未能更新的原因。然而，不同年龄细胞壁的溶解速率存在重大差异。在细胞壁制剂最初30%的溶解过程中，两代旧的细胞壁溶解速度至少比半代旧的细胞壁快七倍。这一结果根据可及性的差异进行了解释。细胞壁被视为由一系列层组成，其年龄随着与膜的距离增加而增加，这样在膜上新合成的细胞壁在随后的生长过程中穿过细胞壁层的厚度，并且只有在到达外表面时才变得易于更新，在掺入后大多以一层的形式，超过一代之后。
