Substrate | C1-Pathway | Intermediate | Enzyme number | ATP cost | NAD(P)H equivalents | Refs. |
---|
CO2 | WLP | acetyl-CoA | 12 | 2 | 11 | [47] |
CO2 | rGlyP | pyruvate | 11 | 4 | 11 | [42, 48] |
CO2 | rTCA cycle | acetyl-CoA | 13 | 4 | 11 | [49, 50] |
CO2 HCO3− | DC/HB cycle | acetyl-CoA | 18 | 6 | 11 | [51] |
CO2 HCO3− | HP/HB cycle | acetyl-CoA | 20 | 8 | 11 | [52, 53] |
HCO3− | 3-HP bicycle | pyruvate | 22 | 10 | 11 | [54, 55] |
CO2 | CBB cycle | GAP | 21a | 14a | 11a | [56] |
CO2 | ASAP | pyruvate | 13a | − 2a | 11a | [13] |
- All calculations are based on converting CO2 equivalents to isobutyraldehyde via pyruvate. NAD(P)H equivalents refer to the reducing power generated from NADH, NADPH, ferredoxin, H2, or H2O.
- WLP: Wood–Ljungdahl pathway, rGlyP: reductive glycine pathway, rTCA cycle: reductive TCA cycle, DC/HB cycle: dicarboxylate/4-hydroxybutyrate cycle, HP/HB cycle: 3-hydroxypropionate/4-hydroxybutyrate cycle, 3-HP bicycle: 3-hydroxypropionate bicycle, CBB cycle: Calvin–Benson–Bassham cycle, ASAP: artificial starch anabolic pathway.
- aHere, we assume that the CBB cycle and ASAP are employed to convert CO2 to glyceraldehyde-3-phosphate (GAP), then a few steps of the glycolysis pathway are utilized to convert GAP to pyruvate, which will be further used to produce isobutyraldehyde