Thursday, July 30, 2009 - 3:30 PM
S160
Genome-enabled studies of Shewanella ecophysiology
Alexander S. Beliaev, Pacific Northwest National Laboratory, 990 Battelle Boulevard, Richland, WA 99352
Shewanella oneidensis MR-1 is a motile, facultative γ-Proteobacterium with remarkable respiratory versatility; it can utilize a range of organic and inorganic compounds as terminal electron acceptors for anaerobic metabolism. To function and compete in environments that are subject to spatial and temporal environmental change, Shewanella must be able to sense and respond to such changes and therefore require relatively robust sensing and regulation systems. The overall goal of our studies is to apply the tools of genomics, leveraging the availability of genome sequence for >20 strains of Shewanella, to better understand the ecophysiology and speciation of respiratory-versatile members of this important genus. To understand these systems, we use genome-based approaches to investigate Shewanella as a system of integrated networks; first describing key cellular subsystems – those involved in signal transduction, regulation, and metabolism - then building towards understanding the function of whole cells and, eventually, cells within populations. As a general approach, we employ complimentary “top-down” – bioinformatics-based genome functional predictions, high-throughput expression analyses, and functional genomics approaches to uncover key genes as well as metabolic and regulatory networks. The “bottom-up” component employs more traditional approaches including genetics, physiology and biochemistry to test or verify predictions. This information is ultimately linked to analyses of signal transduction and transcriptional regulatory systems and used to develop a linked model that will contribute to understanding the ecophysiology of Shewanella in redox stratified environments.