The role of surface stress in the morphology of microbes.
The role of surface stress in the morphology of microbes.
复制标题
表面应力在微生物形态中的作用。
DOI：
10.1099/00221287-128-5-927
复制
发表时间：
1982
期刊：
影响因子：
--
通讯作者：
Doyle,RJ
中科院分区：
文献类型：
--
作者：
Koch,AL;Higgins,ML;Doyle,RJ
许多原核生物的形状可以通过这样的假设来理解，即细胞壁响应于由重力导出的静水压力产生的张力而膨胀。不同的生物体有不同的形状，因为壁生长发生在不同的区域。以前的一篇论文考虑了原核生物生长的最简单的情况，即屎链球菌。在本文中，这一理论的阐述适用于两个进一步的情况下-更完美的球形球菌和杆状细菌。这些情况在数学上更为复杂，因为必须考虑在相当大一部分表面上的生长。这种扩散生长不能用解析的方法来处理，但可以用计算机模拟或用几何论证来处理。球菌的球形可能是由于其整个外表面的扩散生长，也可能是由于带状生长，其中新物质的加入仅发生在分裂隔膜的附近。在分区模型中，必须假设在新外壁的形成中，与壁生长一致的先前沉积的最少量的间隔肽聚糖被重新加工。对于革兰氏阳性杆菌，其中杆的主体是真正的圆柱形，需要三种生长区：（1）向内生长的隔膜的向内边缘，（2）隔膜和新生极的连接处，和（3）圆柱形壁。圆柱形伸长的两种模式是可能的：（a）在一个或几个狭窄的环形区域中添加新的壁，或（B）在整个最内表面上连续添加新的壁材料，并且外层降解。结果表明，后一种情况适用于枯草杆菌。本文还总结了其他地方更详细地研究的有关梭形细菌、革兰氏阴性杆菌和真菌菌丝尖端形态的结果。
The shapes of many prokaryotes can be understood by the assumption that the cell wall expands in response to tension created by the osmotically derived hydrostatic pressure. Different organisms have different shapes because wall growth takes place in different regions. A previous paper considered the simplest case of prokaryotic growth, i.e. that ofStreptococcus faecium. In the present paper, an elaboration of this theory is applied to two further cases - the more perfectly spherical cocci and the rod-shaped bacteria. These cases are more complex mathematically, because growth over a considerable fraction of the surface must be considered. Such diffuse growth cannot be treated analytically, but can be simulated on a computer or handled by geometric arguments.The spherical form of the cocci may result from either diffuse growth over their entire external surface, or from zonal growth in which the addition of new material only occurs in the immediate vicinity of the splitting septum. In the zonal model, it must be assumed that the least amount of previously laid down septal peptidoglycan consistent with wall growth is reworked in the formation of the new external wall. For Gram-positive rods, where the body of the rod is truly cylindrical, three kinds of growth zones are required: (1) the inward edge of the ingrowing septum, (2) the junction of septum and nascent pole, and (3) the cylindrical walls. Two modes for cylindrical elongation are possible: (a) new wall is added in one or a few narrow annular zones, or (b) new wall material is added continuously all over the innermost surface and the outer layer is degraded. It is shown that the latter case applies toBacillus subtilis.Also summarized in this paper are results, developed in more detail elsewhere, concerning the morphology of fusiform bacteria, Gram-negative rods and the hyphal tips of fungi.