Fig. 1

The optimal pathway for threonine production calculated from iJO1366 model and the related genetic engineering targets used in this study. Red lines indicate reactions in the threonine bypass. Through threonine bypass, the theoretical mole yield of PHB was increased from 1 to 1.26. The metabolites are: F6P fructose 6-phosphate, FBP fructose 1,6-bisphosphate, GAP d-Glyceraldehyde 3-phosphate, DHAP dihydroxyacetone phosphate, PEP phosphoenolpyruvate, Pyr pyruvate, OAA oxaloacetate, Asp aspartate, A4P aspartyl-4-phosphate, ASA aspartate semialdehyde, Hser homoserine, PHS homoserine phosphate, Thr threonine, AKB 2-amino-3-ketobutyrate, Gly glycine, Ser serine, MTHF methylene-tetrahydropteroylpolyglutamates, Glu glutamate, AKG 2-oxoglutarate