FIG 4.

Genes essential for growth with electrodes are not required for Fe(III) reduction. (A and B) Growth of scarless deletion mutants of chemosensory genes esnA, esnB, esnC, and esnD, and extracellular conduit clusters extABCD, omcBC, extEFG, and extHIJKL with poised electrodes (A) or insoluble Fe(III) oxides (B). All incubations or reactor experiments were performed for each strain in triplicate. A mutant lacking both inner membrane cytochromes important for using extracellular acceptors (ΔcbcL ΔimcH) was used as a negative control. Representative curves are from replicates in all growth experiments. Error bars represent standard deviations.