生长和分裂是细菌生命周期中两个最基本的过程。传统的微生物学观点认为，所有革兰氏阳性细菌通过逐步酶解切割分裂板的方式完成分裂。但是2015年Science论文报道，葡萄球菌以一种全新发现的“崩裂机制”的物理过程，在毫秒级的时间尺度内瞬间完成分裂，颠覆了该研究领域的认识。“崩裂机制”要求细菌分裂板必须以双层结构形式存在，但该结构模型迄今没有明确的实验证据支持。原子力显微镜技术不仅能够对生物样品进行高分辨率的显微成像，而且能够以纳米操纵技术对样品进行显微操作。申请人的前期研究，证实了使用该技术研究葡萄球菌分裂板结构的可行性。本项目在前期基础上，对金黄色葡萄球菌分裂板结构进行系统研究，揭示并确证分裂板的双层结构形式，阐明分裂板在纳米尺度上的超微表面结构特征、以及分裂板肽聚糖的分子组织结构，为细菌“崩裂机制”提供结构上的证据支持。本项目是细菌学的基础研究，将能够深化对细菌最基本的细胞框架结构的认识。

Growth and division are two most basic processes in bacterial life cycle. Traditional view in microbiological research area considered that all gram-positive bacteria divide by progressively enzymatic splitting on bacterial septa. However, recent new finding reported in Science showed that Staphylococcus divided in a “popping mechanism”, which happened within milliseconds. The findings renewed our knowledge about the way of bacterial division. The “popping mechanism” required that the septum should exist in the form of a double-layered structure. However, there is no clear proof to this proposed structural model to date. Atomic force microscopy is a high-resolution technique in biological research. Moreover, it is able to manipulate biological samples directly with nano-manipulation technique. Our previous works proved that it is feasible to study the structure of septum from Staphylococcus with atomic force microscopy. This program will carry out systematic works on the structure of septum from Staphylococcus aureus based on previous works. Moreover, this program will provide evidence for the double layered structure of bacterial septum, and elucidated the surface structural characteristics of septum at nanoscale, as well as the molecular organizations of peptidoglycan in septum. This work will provide the structural basis for the bacterial “popping mechanism”. This program is a fundamental research in the basic structure of bacterial, and will expand our knowledge about the basic structure of bacterial cells.