Uroporphyrin (UP) is a
porphyrin compound with medical applications and a key precursor for heme
biosynthesis. However, there is no biosynthetic strategy for UP production. In
this study, we present a novel bioprocess for enhanced production of UP in
engineered Escherichia coli. We first implemented the Shemin/C4 pathway
heterologously in an E. coli strain with an enlarged intracellular pool
of succinyl-CoA. Using a plasmid with the trc promoter regulating the
expression of a synthesized gene operon, the effects of key pathway genes,
including hemA, hemB, hemC, and hemD, on UP
biosynthesis were characterized. By cultivating the resulting engineered E.
coli strains in a batch bioreactor with 30 g/L glycerol under aerobic
conditions, up to 901.9 mg/L UP was produced. Most of the synthesized UP was
extracellularly secreted with a high purity more than 80 wt%, facilitating its
downstream purification. The study paves the way for large-scale bio-based
production of UP using synthetic biology and metabolic engineering strategies.