Plasmid transfer in biofilms: integrating fundamental and applied research

生物膜中的质粒转移：整合基础研究和应用研究

• 批准号: 355606-2008
• 负责人: Hausner, Martina
• 金额: $ 1.97万
• 依托单位: Ryerson University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2009
• 资助国家: 加拿大
• 起止时间: 2009-01-01 至 2010-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=431668
• 关键词: Plasmid; transfer; biofilms; integrating; fundamental

The overall objective for the proposed research program is to elucidate the complex interactions of biofilms with their environment and the effect of these interactions on catabolic plasmid transfer, maintenance, dissemination and consequent contaminant biodegradation. To initially focus the project scope, subsurface-derived biofilms will be investigated. The knowledge generated by the proposed research will be crucial not only for the assessment of the success of natural attenuation and biodegradation in the subsurface but can be applied to other environments, such as benthic communities, drinking water biofilms, intestinal biofilms or biofilm reactors. The exchange of genetic information between cells is a common phenomenon in both natural and engineered environments and may significantly contribute to accelerated adjustment of microbial communities. Biofilms, accumulations of microorganisms and extracellular polymeric substances, represent environmental niches characterized by high cell densities and thus provide ideal environments for gene transfer to occur. Catabolic genes or those coding for antibiotic or metal resistance are often carried on plasmids. Plasmid transfer via conjugation (the exchange of genetic information from one cell to another mediated by cell to cell contact) can be viewed as a bioaugmentation strategy and has been shown to contribute to the spread of catabolic genes in various ecosystems. Despite the fact that plasmid transfer is known to play a critical role in biofilms, little is known about the exact way in which the surrounding environment influences conjugation frequencies and fate of plasmids in biofilms. The proposed work will test the hypothesis that subsurface biofilms facilitate plasmid transfer and consequently contribute to an increased biodegradation potential in aquifers by conducting a very careful set of experiments in continuous flow-through chambers and lab scale microcosms simulating "real world" conditions using well characterized catabolic plasmids. The findings from the proposed work will span a bridge to clinical and public health microbiology (spread of antibiotic resistance plasmids in biofilms) and bioremediation strategies.

拟议的研究计划的总体目标是阐明生物膜与环境的复杂相互作用，以及这些相互作用对分解代谢质粒转移，维持，传播和随后的污染物生物降解的影响。为了初步确定项目范围，将对地下衍生生物膜进行调查。拟议的研究所产生的知识不仅对评估地下自然衰减和生物降解的成功与否至关重要，而且可以应用于其他环境，如底栖生物群落、饮用水生物膜、肠道生物膜或生物膜反应器。细胞之间的遗传信息交换是自然和工程环境中的常见现象，并可能显著有助于加速微生物群落的调整。生物膜，微生物和细胞外聚合物的积累，代表了以高细胞密度为特征的环境小生境，从而为基因转移提供了理想的环境。分解代谢基因或那些编码抗生素或金属抗性的基因通常携带在质粒上。通过接合（细胞与细胞接触介导的遗传信息从一个细胞到另一个细胞的交换）的质粒转移可以被视为一种生物增强策略，并已被证明有助于分解代谢基因在各种生态系统中的传播。尽管已知质粒转移在生物膜中起关键作用，但对周围环境影响生物膜中质粒的接合频率和命运的确切方式知之甚少。拟议的工作将测试的假设，地下生物膜促进质粒转移，从而有助于提高生物降解潜力的含水层进行了一系列非常仔细的实验，在连续的流通室和实验室规模的缩影模拟“真实的世界”的条件下，使用良好的特征分解代谢质粒。拟议工作的发现将跨越临床和公共卫生微生物学（生物膜中抗生素耐药性质粒的传播）和生物修复策略的桥梁。