Fig. 5
Modular optimization of biliverdin production by combining push module and pull module. a Schematic representation of different combinations. The genes hemAM, hemL, hemQ, hmuO are assembled and rearranged with the plasmids that have different origins. b Biliverdin and heme production of recombinant strains with different gene combinations. White box, concentration of heme; black box, concentration of biliverdin