Metabolic Modification of Escherichia coli BL21 (DE3) to Produce Shinorine

Shinorine, a naturally occurring UV-absorbing compound belonging to the class of mycosporine-like amino acids (MAAs), has attracted considerable attention for its applications in pharmaceuticals, cosmetics, and biomaterials. However, conventional production methods based on extraction from marine organisms are constrained by low yield, limited availability, and environmental sustainability concerns. In this study, we developed a microbial cell factory for the efficient biosynthesis of shinorine in Escherichia coli. Specifically, the transaldolase gene in the pentose phosphate pathway (PPP) was precisely disrupted to block the metabolic conversion of sedoheptulose-7-phosphate (S7P), thereby enhancing its intracellular accumulation. In parallel, a cyanobacterial shinorine biosynthetic gene cluster (Ava_3858–Ava_3855) was heterologously expressed in the engineered strain, enabling the reconstruction of a functional biosynthetic pathway utilizing S7P as a key precursor. This integrated metabolic engineering strategy effectively overcomes the limitations of traditional extraction methods and significantly improves shinorine production. Moreover, the approach provides a versatile framework for the microbial synthesis of other high-value natural products, with broad implications for sustainable biomanufacturing.