Engineering the FK228 biosynthetic gene clusters for high-yield production

FK228 (romidepsin) is a potent HDAC inhibitor; however, its clinical application is severely constrained by low natural yields and the genetic intractability of its native producer. Here, we leveraged the established Burkholderia chassis KOGC1 to develop a high-performance platform for FK228 production. Through systematic fermentation optimization, we addressed major production constraints including potential end-product toxicity and precursor supply. Specifically, the integration of XAD-16 resin adsorption together with the combined feeding of key amino acids (cysteine, valine, and threonine) elevated the titer to 743.5 mg/L. Subsequent refactoring of the biosynthetic gene cluster and promoter engineering further increased the titer to 1109.4 mg/L. Furthermore, the engineered strain exhibited remarkable genetic stability over five generations without antibiotic selection, which may help address a key barrier to future scale-up. Overall, this study establishes a highly productive laboratory-scale FK228 biosynthetic platform, providing a foundation for future process development of this important therapeutic agent.