Microbe Profile: Saccharopolyspora erythraea: antibiotic factory and biosynthetic model organism

Graphical Abstract Saccharopolyspora erythraea exists as white and red variants, both of which produce the polyketide natural product erythromycin, an antibiotic and World Health Organization essential medicine. Erythromycin is the precursor for semi-synthesis of the second-generation macrolide antibiotics azithromycin and clarithromycin. The biosynthesis of erythromycin involves a modular polyketide synthase, and this system is the archetype for understanding how assembly-line enzymes function and can be engineered to produce new-to-nature molecules.