BioDesign Research / 2021 / Article / Fig 7

Research Article

In-Depth Computational Analysis of Natural and Artificial Carbon Fixation Pathways

Figure 7

Comparison of carbon fixation pathways using methanol as a substrate for the production of pyruvate with the Enzyme Cost Minimization algorithm. “(w/o SHMT)” indicates that the cost of the serine hydroxymethyltransferase are not included in the respective pathway’s activity. The concentration of CO2 was assumed to be 1 mM and the concentration of HCO3- to be 10 mM. (a) Pathway-specific activities with standard deviations and the full name of the main pathways and the connecting modules to transform their primary product to pyruvate. Pathway abbreviations: CBB(PTS): phosphatase-free CBB cycle; HP-bicycle(glyox): glyoxylate producing subcycle of the 3-HP bicycle; GAPtoPyr: glycolysis; FCL: formaldehyde:NADP+ oxidoreductase (formyl-CoA-forming); GlyoxToPyr: GCL/GDH route; b-OH-AspCycle: β-hydroxyaspartate cycle; AcCoAtoOAA(HP): acetyl-CoA to oxaloacetate-converting module derived from the 3-HP/4-HB cycle using either ADP- or AMP-producing CoA-ester synthases; rCC-AcCoAtoPyr: acetyl-CoA to pyruvate-converting module derived from the rCCC; GlyoxToOAA: glyoxylate- to oxaloacetate-converting module based on the Serine cycle. (b) Pathway-specific activities compared to product-substrate yield. The overall stoichiometries of all pathways and modules are listed in Table 1 and supplementary Table S4 and S5. The small letters label each pathway and correspond to the labels and the respective pathway combinations in (a).