title: Metabolic flux analysis of Shewanella spp. reveals evolutionary robustness in central carbon metabolism.
abstract: Shewanella spp. are a group of facultative anaerobic bacteria widely distributed in marine and freshwater environments. In this study, we profiled the central metabolic fluxes of eight recently sequenced Shewanella species grown under the same condition in minimal medium with [3-13C] lactate. Although the tested Shewanella species had slightly different growth rates (0.23-0.29 h(-1)) and produced different amounts of acetate and pyruvate during early exponential growth (pseudo-steady state), the relative intracellular metabolic flux distributions were remarkably similar. This result indicates that Shewanella species share similar regulation in regard to central carbon metabolic fluxes under steady growth conditions: the maintenance of metabolic robustness is not only evident in a single species under genetic perturbations (Fischer and Sauer, 2005; Nat Genet 37(6):636-640), but also observed through evolutionary related microbial species. This remarkable conservation of relative flux profiles through phylogenetic differences prompts us to introduce the concept of metabotype as an alternative scheme to classify microbial fluxomics. On the other hand, Shewanella spp. display flexibility in the relative flux profiles when switching their metabolism from consuming lactate to consuming pyruvate and acetate.
authors.affiliation: Virtual Institute of Microbial Stress and Survival, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Yinjie J
authors.initials: YJ
authors.lastname: Tang
authors.forename: Hector Garcia
authors.initials: HG
authors.lastname: Martin
authors.forename: Paramvir S
authors.initials: PS
authors.lastname: Dehal
authors.forename: Adam
authors.initials: A
authors.lastname: Deutschbauer
authors.forename: Xavier
authors.initials: X
authors.lastname: Llora
authors.forename: Adam
authors.initials: A
authors.lastname: Meadows
authors.forename: Adam
authors.initials: A
authors.lastname: Arkin
authors.forename: Jay D
authors.initials: JD
authors.lastname: Keasling
mesh_terms: D019342:Acetic Acid / Q000378:metabolism; D002244:Carbon / Q000378:metabolism*; D002247:Carbon Isotopes / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry; D019344:Lactic Acid / Q000378:metabolism; D019289:Pyruvic Acid / Q000378:metabolism; D020592:Shewanella / Q000378:metabolism*
chemical_list: D002247:Carbon Isotopes; D003470:Culture Media; D019344:Lactic Acid; D002244:Carbon; D019289:Pyruvic Acid; D019342:Acetic Acid