Fig. 3.

Electron transfer flux distribution predicted for ferrous ion, tetrathionate and thiosulfate metabolism: A flux map illustrating the electron transfer metabolism for ferrous ion (FIM), tetrathionate (TTM) and thiosulfate (TSM) metabolism. Reactions are specified in capital letters, while metabolites in lowercase letters and yellow circles. Arrows indicate the direction of enzymatic activity and the arrow thicknesses are proportional to the flux through each reaction (a thicker arrow has a larger flux). Light blue arrows represent the electron flow in the network. Visually undetectable fluxes for being so small were increased by a corresponding factor specified next to the corresponding reaction in the map. The diagram shows the energy-conserving ion translocating reactions, each labeled with the stoichiometry of the translocated ion. Proton translocation stoichiometry predicted reactions are shown in brown. The different colored regions correspond to the tree modeled spaces: cytoplasm (light blue), periplasm (yellow) and the extracellular space (white). For each network the corresponding standard reduction potential (in mV) associated with a specific transformation was specified. The uptake of h2co3 for each simulation was constraint at 2 mmol/g DW/h, and the corresponding electron donor was allowed to freely enter the system. FBA was performed for FIM, TTM and TSM. Due to flux similarities results, TTM and TSM were plotted together. For TTM, reactions, metabolites and fluxes we potted according to the previous description. In the case of TSM, reaction fluxes different from the ones obtain in TTM, were plotted in orange. For TTM and TSM, an additional flux distribution, called as parallel solution, was plotted. This solution was obtained when constraining CYTBO3 and CYTBD ub and lb to 0. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)