Fig. 3

Output voltage of the WT and four recombinant S. oneidensis strains (XE, GE, XS, and GS) with different carbon sources in the anodic chamber of MFCs. The output voltage of the four strains XE, GE, XS, and GS, using lactate and xylose as the carbon source, respectively. 18 mM lactate (the favourable carbon source of Shewanella) was added at the initiation of MFC operations (as indicated by the black arrow). Upon the depletion of lactate and vanishing of electricity output, 18 mM xylose was added at ~260 h as the carbon source (as indicated by the blue arrow) to illustrate the power generation capability of these S. oneidensis strains using xylose as the sole carbon source. The error bars were calculated from triplicate experiments