Metabolomic analyses show that electron donor and acceptor ratios control anaerobic electron transfer pathways in Shewanella oneidensis

Hui Wang, Elon Correa, Warwick B. Dunn, Catherine L. Winder, Royston Goodacre, Jonathan R. Lloyd

    Research output: Contribution to journalArticlepeer-review

    Abstract

    This study investigated the physiological impact of changing electron donor-acceptor ratios on electron transfer pathways in the metabolically flexible subsurface bacterium Shewanella oneidensis, using batch and chemostat cultures, with an azo dye (ramazol black B) as the model electron acceptor. Altering the growth rate did result in changes in biomass yield, but not in other key physiological parameters including the total cytochrome content of the cells, the production of extracellular flavin redox shuttles or the potential of the organism to reduce the azo dye. Dramatic increases in the ability to reduce the dye were noted when cells were grown under conditions of electron acceptor (fumarate) limitation, although the yields of extracellular redox mediators (flavins) were similar under conditions of electron donor (lactate) or acceptor limitation. FT-IR spectroscopy confirmed shifts in the metabolic fingerprints of cells grown under these contrasting conditions, while spectrophotometric analyses supported a critical role for c-type cytochromes, expressed at maximal concentrations under conditions of electron acceptor limitation. Finally, key intracellular metabolites were quantified in batch experiments at various electron donor and acceptor ratios and analysed using discriminant analysis and a Bayesian network to construct a central metabolic pathway model for cells grown under conditions of electron donor or acceptor limitation. These results have identified key mechanisms involved in controlling electron transfer in Shewanella species, and have highlighted strategies to maximise reductive activity for a range of bioprocesses. © 2012 Springer Science+Business Media New York.
    Original languageEnglish
    Pages (from-to)642-656
    Number of pages14
    JournalMetabolomics
    Volume9
    Issue number3
    DOIs
    Publication statusPublished - Jun 2013

    Keywords

    • Azo dye
    • Bayesian networks
    • Cytochrome c
    • Electron transport
    • Flavins
    • Metabolism

    Fingerprint

    Dive into the research topics of 'Metabolomic analyses show that electron donor and acceptor ratios control anaerobic electron transfer pathways in Shewanella oneidensis'. Together they form a unique fingerprint.

    Cite this