Fig. 4.

Illustrative examples of FaceCon modules. OptORF was used in conjunction with the FaceCon modules to create unique phenotypes that would be difficult to produce by OptORF alone. (A) A coupling module was added to guarantee that weak coupling would occur but not directional coupling. The dashed line on the x-axis indicates where the excluded region begins. (B) The chemical level module was added to prevent any production of the undesired compound I_ex. The hatched region indicates the excluded region imposed by the module. (C) The direct constraint module was added to force the co-production of E_ex and I_ex for large growth rates. For all panels, red arrows and x׳s on the network map indicate a reaction knockout. Dotted vertical lines show the μ^min and v^min values used in OptORF and FaceCon modules, respectively. (For interpretation of the references to color in this figure, the reader is referred to the web version of this article.)