FIG 2.

ETC composition influences tetrazolium dye reduction. (A) Depiction of the terminal oxidase complexes present in the WT (center) and the strains PaCco (left) and PaCio (right). Electrons enter the ETC via primary dehydrogenases (not shown) and are transferred to the quinone pool (Q). Reduced Q can act as a substrate for the quinol oxidases (Cyo and Cio) or the cytochrome bc₁ complex (bc₁). A cytochrome c protein mediates electron transfer between bc₁ and the terminal oxidases Cco1, Cco2, and Cox. (B) The 32 carbon sources that support PA14 growth, grouped based on tetrazolium dye reduction patterns of each phenazine-producing and phenazine-null strain. Groups were designated based on data from three experiments. Carbon sources highlighted in colored boxes are those on which dye reduction patterns changed relative to the strains with the full complement of terminal oxidases (i.e., WT and Δphz, the center column). Carbon source descriptors are as provided by the manufacturer.