Metabolic pathway analysis for in silico design of efficient autotrophic production of advanced biofuels

Bioresources and Bioprocessing

Table 1 Existing pathways and predicted yields performance by recombinant strains and designed mutants with multiple gene deletions for maximizing isobutanol and hexadecanol synthesis

Strains	Total pathways	P-syn pathways^a	P-frac (%)^b	Y_X (g/g)^c	Y_P (g/g)^d
Isobutanol (SCA)
WT-Isobutanol	8940	1068	12	0.22–0.57	0–0.42
∆GG5r∆ACT1∆AcDH^e	1476	252	17	0.22–0.57	0–0.42
∆GG5r∆ACT1∆AcDH^e under gas feeding control at fq_H2 > 0.67^f	252	252	100	0.31	0.21–0.42
Hexadecanol (LCA)
WT-Hexadecanol	9264	1392	15	0.22–0.57	0–0.34
∆CAL4∆ACT1∆AcDH^e	3420	972	28	0.22–0.57	0–0.34
∆CAL4∆ACT1∆AcDH^e under gas feeding control at fq_H2 > 0.67^f	864	864	100	0	0.20–0.34

^aAvailable metabolic pathways for product synthesis
^b Percent of product synthesizing pathways from total available metabolic pathways
^cPredicted cell yield during growth condition
^dPredicted product yield during non-growth condition
^eGenes and enzymes corresponding to deleted reactions are GG5r, triosephosphate isomerase (tpiA); ACT1, acetoacetyl-CoA thiolase/Acetyl-CoA acetyltransferase (phaA); AcDH, acetaldehyde dehydrogenase 1/2 (mhpF/acoD); CAL4, fructose/Sedoheptulose bisphosphatase (cbbF)
^ffq_H2 is fraction of H₂ gas input relative to total gas input of CO₂, H₂ and O₂ mixture