Fig. 6. Schematic representation of the proposed regulation of catabolic pathways in G. metallireducens at high (A) and low (B) substrate concentrations. Thick blue arrows represent simplified degradation pathways. Open arrows indicate the positive (+) or negative (−) effect on expression of degradation pathways by a corresponding substrate. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of the article.)