In Silico Analysis of Bioethanol Overproduction by Genetically Modified Microorganisms in Coculture Fermentation

Table 2

Metabolic engineering strategies for ethanol overproduction by recombinant E.  coli strain ZSC113 [22].

Number	Metabolic engineering strategy	Deleted reaction
1	Deletion of acetate kinase (ack)	Acetate + ATP ↔ Acetyl phosphate + ADP
2	Deletion of pyruvate formate lyase (pfl)	Acetyl-CoA + Formate → CoA + Pyruvate
3	Deletion of phosphotransacetylase (pta)	Acetyl-CoA + Phosphate ↔ Acetyl phosphate + CoA
4	Deletion of fumarase (fum) + pfl	Fumarate + H2O ↔ L-malate; Acetyl-CoA + Formate → CoA + Pyruvate
5	Deletion of phosphogluconate dehydrogenase (gnd) + ack	6-Phospho-D-gluconate + NADP → Ribulose 5-phosphate + NADPH + CO2; Acetate + ATP ↔ Acetyl phosphate + ADP
6	Deletion of glutamate dehydrogenase (gdh) + pta	Glutamate + NADP + H2O ↔ 2-Oxoglutarate + NADPH + NH3; Acetyl-CoA + Phosphate ↔ Acetyl phosphate + CoA
7	gdh + ack	Glutamate + NADP + H2O ↔ 2-Oxoglutarate + NADPH + NH3; Acetate + ATP ↔ Acetyl phosphate + ADP
8	gdh + pfl	Glutamate + NADP + H2O ↔ 2-Oxoglutarate + NADPH + NH3; Acetyl-CoA + Formate → CoA + Pyruvate
9	Deletion of methylenetetrahydrofolate dehydrogenase (mthfd) + ∆ack	5,10-Methylenetetrahydrofolate + NADP ↔; 5,10-Methenyltetrahydrofolate + NADPH; Acetate + ATP ↔ Acetyl phosphate + ADP
10	Deletion of carbamate kinase (cbm) + ack	ATP + CO2 + NH4  ↔ ADP + Carbamoyl phosphate; Acetate + ATP ↔ Acetyl phosphate + ADP