Engineering of the redox imbalance of Fusarium oxysporum enables anaerobic growth on xylose

Gianni Panagiotou, Paul Christakopoulos, Thomas Grotkjær, Lisbeth Olsson

    Research output: Contribution to journalJournal articleResearchpeer-review

    Abstract

    Dissimilatory nitrate reduction metabolism, of the natural xylose-fermenting fungus Fusarium oxysporum, was used as a strategy to achieve anaerobic growth and ethanol production from xylose. Beneficial alterations of the redox fluxes and thereby of the xylose metabolism were obtained by taking advantage of the regeneration of the cofactor NAD(+) during the denitrification process. In batch cultivations, nitrate sustained growth under anaerobic conditions (1.21 g L-1 biomass) and simultaneously a maximum yield of 0.55 moles of ethanol per mole of xylose was achieved, whereas substitution of nitrate with ammonium limited the growth significantly (0.15 g L-1 biomass). Using nitrate, the maximum acetate yield was 0.21 moles per mole of xylose and no xylitol excretion was observed. Furthermore, the network structure in the central carbon metabolism of F. oxysporum was characterized in steady state. F. oxysporum grew anaerobically on [1-C-13] labelled glucose and unlabelled xylose in chemostat cultivation with nitrate as nitrogen source. The use of labelled substrate allowed the precise determination of the glucose and xylose contribution to the carbon fluxes in the central metabolism of this poorly described microorganism. It was demonstrated that dissimilatory nitrate reduction allows F oxysporum to exhibit typical respiratory metabolic behaviour with a highly active TCA cycle and a large demand for NADPH.
    Original languageEnglish
    JournalMetabolic Engineering
    Volume8
    Issue number5
    Pages (from-to)474-482
    ISSN1096-7176
    DOIs
    Publication statusPublished - 2006

    Keywords

    • nitrogen source
    • metabolic network analysis
    • fusarium oxysporum
    • C-13-labelling experiments
    • redox balance

    Fingerprint

    Dive into the research topics of 'Engineering of the redox imbalance of Fusarium oxysporum enables anaerobic growth on xylose'. Together they form a unique fingerprint.

    Cite this