Biofilm Formation by Variovorax paradoxus (pilot)

本项目将研究一种广泛存在的革兰氏阴性需氧菌的生物膜形成， 异食菌该项目的具体目标是了解细胞外聚合物（EPS）生产的遗传和生理基础，以及这种生物合成途径如何影响表面稳定聚集结构（生物膜）的形成。该项目将通过插入诱变鉴定EPS生物合成所必需的基因和相应产物，并同时鉴定不再能够形成生物膜的突变体。进一步的工作将通过敲除基因的互补来表征各种基因在EPS生物合成和生物膜形成中的作用， 使用无启动子GFP构建体分析显影膜中的基因表达。 Variovorax paradoxus广泛存在于环境中，并且先前已被确定为异生物质污染物的降解者。因此，利用这种微生物的发达的遗传和生理系统可用于生物修复环境，以去除污染场地的污染物。生物膜生活方式与许多革兰氏阴性细菌感染以及抗生素耐药性密切相关。因此，使用用于生物膜形成的多个模型系统是极其重要的，其允许发现可能抑制多种生物体中生物膜形成的潜在治疗靶标。EPS生物合成途径与许多系统中的生物膜形成和发病机制密切相关。通过鉴定对奇异弧菌生物膜形成和EPS合成至关重要的基因，并与相关植物和人类病原体的可用测序基因组进行比较，我们可以在细胞中鉴定这些靶点用于化疗。

This project will investigate biofilm formation by a widespread gram-negative aerobic bacterium, Variovorax paradoxus. The specific aims of this project will be to understand the genetic and physiologic basis for extracellular polymeric substance (EPS) production and how this biosynthetic pathway influences the formation of stable aggregated structures (biofilms) on surfacs. The project will identify the genes and corresponding products essential for EPS biosynthesis by insertional mutagenesis, and will simultaneously identify mutants that are no longer capable of forming biofilms. Further work will characterize the roles of various genes in EPS biosynthesis and biofilm formation by complementation of the knocked out genes, and analysis of gene expression in the developing film using a promoterless GFP construct. Variovorax paradoxus is widespread in the environment, and has previously been identified as a degrader of xenobiotic contaminants. Well developed genetic and physiological systems utilizing this microbe may thus be utilized in bioremediative settings to remove contaminants from polluted sites. The biofilm lifestyle has been strongly implicated in the course of many gram negative bacterial infections, as well as in antibiotic resistance. It is therefore extremely important to use multiple model systems for biofilm formation that allow for the discovery of potential therapeutic targets that might inhibit biofilm formation in a variety of organisms. The EPS biosynthesis pathways are strongly linked to biofilm formation and pathogenesis in a number of systems. By identifying genes essential to biofilm formation and EPS synthesis in V. paradoxus, and comparison to the available sequenced genomes of related plant and human pathogens, we may identify such targets in the cell for chemotherapy.