Structural Biology of Bacillus subtilis Biofilms

微生物形成表面附着的群落，称为生物膜，其促进协同生活方式，其中细胞外基质（ECM）提供针对环境压力的保护，包括宿主免疫反应或抗生素治疗。显然，它们的发生可能产生健康并发症，例如与植入物或牙齿有关。ECM形成的原理很重要，特别是因为它的组分不仅具有结构功能，而且还参与信号传导过程。对ECM的结构和功能的改进的知识可以允许开发新的和更好地定制的抗菌治疗，特别是针对生物膜形成（耐药性）病原体的那些。然而，目前缺乏在分子水平上研究体内情况的方法学途径。固态NMR，电子显微镜和质谱成像的最新发展承诺进入ECM，特别是进入单个组分的分布及其相互作用的前所未有的观点。这是革兰氏阳性菌B的生物膜。subtilis作为模型系统。它们是很有吸引力的目标，因为已有一些机理研究，可为后续调查提供燃料。作为一个开始，我们确定在体内结构的TasA原纤维，研究它们的相互作用与TapA和EPS在体外和生物膜中的生物物理技术和结构的方法，并研究整体生物膜的组成。该项目的长期目标是在各种尺度上对生物膜结构进行全面的、充分解析的表示。长期目标是检测整个生物膜上或ECM内的大或小组分的梯度。 该结果对于理解炭疽B.和金黄色B.的存活和感染性是相关的。

Microorganisms form surface-attached communities, termed biofilms, which promote a synergistic lifestyle where an extracellular matrix (ECM) provides protection against environmental stress, including host immune reactions or antibiotic treatment. Evidently, their occurrence may produce health complications, for example in connection with implants or on teeth. The principles according to which the ECM is formed are important to understand, especially as its components do not only serve structural functions but can also be involved in signalling processes. An improved knowledge on the structure and function of the ECM could allow the development of new and better tailored antibacterial treatments, particularly those directed against biofilm forming (antibiotic-resistant) pathogens. Yet, there is a lack of methodological approaches for investigating the in vivo situation on the molecular level. Recent developments in solid-state NMR, electron microscopy and imaging by mass spectrometry promise access to unprecedented views into the ECM and in particular into the distribution of individual components and their interactions. Here, biofilms of the gram-positive organism B. subtilis serve as a model system. They are attractive targets, since a number of mechanistic studies are available that fuel follow-up investigations. As a start, we determine the in-vivo structure of TasA fibrils, investigate their interactions with TapA and EPS in vitro and in biofilms by biophysical techniques and structural methods, and study overall biofilm composition. The long-term goal of this project is a comprehensive, sufficiently resolved representation of biofilm structure at various scales. A long-term aim is the detection of gradients of large or small components over an entire biofilm or within the ECM. The results are relevant for understanding B.anthracis and B.aureus survival and infectivity.