Studies of Bacterial Endospore Germination

摘要 细菌内生孢子是地球上最持久和抵抗力最强的生命形式，能够在 休眠数十年，并在一系列其他生物无法承受的潜在致死处理中存活下来 approach.令人惊讶的是，这些休眠细胞可以感受到一个支持生长的环境， 在几个小时内通过发芽过程生长。对细胞结构的主要孢子特异性修饰， 细胞内容物驱动休眠和抵抗杀死处理，休眠孢子具有 在萌发过程中迅速逆转这些修饰的机制。这项研究的长期目标是 充分理解决定孢子特性的细胞修饰的细节， 孢子开始萌发，一连串的事件导致新陈代谢和生长的恢复 细胞质蛋白在脱水的孢子核中高度稳定，但大多数萌发活性 蛋白质位于膜的外表面，处于水合环境中，并且必须在长期使用过程中保持稳定。 休眠和其他机制的潜在身体攻击。这项工作的首要假设是 大多数的发芽感应和调节装置都存在于非常稳定的多蛋白中 复合物内或上的孢子膜，作为一个独特的稳定平台，由于其最小的 膜流动性拟议工作的具体目标是确定这些蛋白质的组成部分 复合物，以检查膜结构的潜在独特修饰，并检查 孢子膜蛋白的降解及其对萌发进程的影响。拟议工作 还包括筛选发现在发芽过程中发挥先前未知作用的基因。 孢子在引发几种人类和动物疾病以及污染中起着重要作用 和食品的降解。孢子被用作递送所需药物的高度稳定的载体。 在许多工业和农业产品的代谢活动，并已开发为稳定的车辆， 疫苗运送在所有这些情况下，孢子萌发在该过程的成功中起着关键作用： 发病机理或活性的递送。因此，对发芽的充分理解可以推动避免 或改善这些过程。阻断发芽可防止发病，同时刺激高效 萌发使孢子易于受到简单得多的去污方法的影响。刺激更高 萌发效率或速率可以提高孢子基产品的有效性。

Abstract Bacterial endospores are the most persistent and resistant forms of life on earth, able to remain in dormancy for decades and to survive a range of potential killing treatments that no other organisms can approach. Amazingly, these dormant cells can sense a growth-supportive environment and return to vegetative growth within hours through the process of germination. Major spore-specific modifications to cell structure and cellular content drive dormancy and resistance to killing treatments, and the dormant spores possess mechanisms to rapidly reverse these modifications during germination. The long-term goal of this study is to fully understand the details of cellular modifications that determine spore properties, the mechanism by which the spore initiates germination, and the cascade of events that lead to a resumption of metabolism and growth Cytoplasmic proteins are highly stabilized in the dehydrated spore core, but most germination-active proteins are on the membrane outer surface, in a hydrated environment, and must be stabilized during long-term dormancy and potential physical assault by other mechanisms. The overriding hypothesis of the proposed work is that the majority of the germination sensing and regulating apparatus is found in very stable multiprotein complexes in or on the inner spore membrane, which serves as a uniquely stable platform due to its minimal membrane fluidity. The specific goals of the proposed work are to define the components of these protein complexes, to examine potentially unique modifications of the membrane structure, and to examine the degradation of spore membrane proteins and effects this has on progression of germination. The proposed work also includes screens for discovery of genes that play previously unknown roles in the germination process. Spores play important roles in the initiation of several human and animal diseases, and in contamination and degradation of food products. Spores are used as the highly stable vehicles for the delivery of desirable metabolic activities in many industrial and agricultural products, and have been developed as stable vehicles for vaccine delivery. In all of these cases, spore germination plays a key role in the success of the process: pathogenesis or delivery of an activity. A full understanding of germination can therefore drive methods to avoid or improve these processes. Blocking germination can prevent pathogenesis, while stimulating highly efficient germination renders the spores susceptible to much simpler decontamination methods. Stimulating higher germination efficiency or rate can improve the effectiveness of a spore-based product.