Fig. 3From: Optimization of hydrogenobyrinic acid biosynthesis in Escherichia coli using multi-level metabolic engineering strategiesFurther optimization of the expression rates of ALAS, PBGS, PBGD and UROS in vivo. a Analysis of RBS intensity of five strains with high fluorescence (red series) and five low fluorescence strains (blue series). b Change of the HBA titer after optimizing the expression of hemD on plasmid p15ASI-25. From JPT25D2 to JPT25D5, the RBS intensity decreased gradually, and all intensities were higher than that of the original RBS. c Change of the HBA titer after optimizing the expression of hemB on plasmid p15ASI-25D2. From JPT25D2 to JPT25D2B8, the RBS intensity decreased gradually. Error bars indicate standard deviations from three biological replicatesBack to article page