Cell-surface interactions of Shewanella oneidensis MR-1 - role of eDNA and nucleolytic activity

在缺氧沉积环境中，异化铁还原菌在铁氧化物及伴生金属/有机污染物的循环中起着关键作用。在自然界中，不溶性含金属矿物质的还原是通过在基质表面形成微生物生物膜的直接代谢相互作用发生的。微生物-表面相互作用的启动和细菌生活方式转换的开始的分子机制尚不清楚。拟就的异化铁还原模式生物——同一希瓦氏菌MR-1的研究将使用全球转录组学和蛋白质组学分析来鉴定在代谢惰性或可接近表面上粘附差异调节的基因模式。然后，这些将用于创建荧光和基于lacz的报告系统，以便在微观上监测表面粘附后的细胞活动，并追踪潜在的调节事件和环境刺激。与此同时，将更详细地研究一个通过初步转录组学分析和转座子突变独立确定的调控系统，该系统将参与该过程。该方法将对代谢和非代谢微生物表面相互作用的开始产生新的见解。

Dissimilatory iron-reducing bacteria play a critical role in cycling iron oxides and associated metal/organic contaminants in anoxic sedimentary environments. In nature, reduction of insoluble metal-containing minerals occurs through direct metabolic interaction, mediated by the formation of microbial biofilms at the substrate surface. The molecular mechanisms underlying the initiation of microbe-surface interactions and the onset of a bacterial life style switch are not well understood. The proposed study on the model-organism for dissimilatory iron reduction, Shewanella oneidensis MR-1, will use global transcriptomic and proteomic profiling to identify gene patterns differentially regulated on adhesion to metabolically inert or accessible surfaces. These will then be used to create fluorescent and lacZ-based reporter systems in order to microscopically monitor cellular activities following surface adhesion and to track down underlying regulatory events and environmental stimuli. In parallel a regulatory system will be studied in more detail that was identified independently by preliminary transcriptomic analysis and transposon mutagenesis to be involved in that process. The approach will yield novel insights into the initiation of metabolic and non-metabolic microbe-surface interaction.