Mechanisms Involved in Bacterial Cellulose Biosynthesis

细菌纤维素生物合成的机制

• 批准号: 418310-2012
• 负责人: Weadge, Joel
• 金额: $ 2.19万
• 依托单位: Wilfrid Laurier University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=531095
• 关键词: Mechanisms; Involved; Bacterial; Cellulose; Biosynthesis

Escherichia and Salmonella species form highly resistant biofilms, composed of cellulose and curli fimbriae, that helps these bacteria elude detection by the immune system and increases their tolerance to antimicrobial agents and harsh environmental factors. The cellulose component specifically confers protection from mechanical, chemical and biological stresses and promotes adherence to a number of surfaces, such as epithelial cells, a variety of foods, water distribution systems and more. Thus, knowledge of biofilm formation and composition is of critical importance to understanding how these bacteria establish themselves in environmental reservoirs, thereby enabling them to continue to threaten our food/water security, industrial processes and general health. Bacterial cellulose is also gaining bioengineering significance as it has unique physical/chemical properties that provide significant advantages when compared to algal or plant derived cellulose. These properties have been successfully exploited for the generation of novel wound dressings, bio-plastics, biofuels and bio-inert supports for tissue regeneration. Even though the biological and industrial implications of bacterial cellulose are expanding, little is known about the synthesis and export of this polymer by bacteria. Genetic studies have demonstrated that seven genes, bcsABZCEFG, are essential for the biosynthesis of cellulose in Enteric bacteria. We hypothesize that the Bcs proteins come together to form a bacterial cell wall spanning complex that facilitates the coordinated polymerization, export and release of cellulose from the cell. Using E. coli as a model system, our goals are to utilize a multidisciplinary approach to characterize the structure and function of each of the proteins involved in these processes. The results of this research will be key to revealing unique approaches to circumvent the biofilm barrier and will and lay the groundwork for designing polymers (or enzymes) with specific properties for medical/industrial applications. Equally important, a detailed understanding of the synthesis/export of cellulose will lead to the discovery of important principles relating to polysaccharide synthesis and biofilm development across bacterial species.

埃希氏菌和沙门氏菌形成由纤维素和卷毛菌毛组成的高度耐药的生物膜，帮助这些细菌逃避免疫系统的检测，并提高它们对抗菌剂和恶劣环境因素的耐受性。纤维素成分专门提供针对机械、化学和生物应力的保护，并促进对许多表面的粘附，例如上皮细胞、各种食物、配水系统等。因此，了解生物膜的形成和组成对于了解这些细菌如何在环境储存库中生存至关重要，从而使它们能够继续威胁我们的食品/水安全、工业过程和总体健康。细菌纤维素还具有生物工程意义，因为它具有独特的物理/化学特性，与藻类或植物来源的纤维素相比具有显着的优势。这些特性已成功用于生产新型伤口敷料、生物塑料、生物燃料和用于组织再生的生物惰性支持物。尽管细菌纤维素的生物学和工业意义正在扩大，但人们对细菌合成和输出这种聚合物的情况知之甚少。遗传学研究表明，bcsABZCEFG 七个基因对于肠道细菌中纤维素的生物合成至关重要。我们假设 Bcs 蛋白聚集在一起形成跨越细菌细胞壁的复合物，促进细胞中纤维素的协调聚合、输出和释放。使用大肠杆菌作为模型系统，我们的目标是利用多学科方法来表征这些过程中涉及的每种蛋白质的结构和功能。这项研究的结果将是揭示绕过生物膜屏障的独特方法的关键，并将为设计具有特定性能的医疗/工业应用聚合物（或酶）奠定基础。同样重要的是，对纤维素合成/输出的详细了解将导致发现与跨细菌物种的多糖合成和生物膜发育相关的重要原理。