Coupling optimization of cell morphology and key enzyme membrane localization for enhanced synthesis of high molecular weight heparosan by Corynebacterium glutamicum.

High-molecular weight heparosan (HMW-heparosan) is a member of the glycosaminoglycan family. It possesses various chemical and physical properties suitable for a range of high-quality tissue engineering biomaterials, gels, scaffolds, and drug delivery systems. In this work, we engineered Corynebacterium glutamicum to produce HMW-heparosan with satisfied molecular weight. On the basis of the enhancement of precursor synthesis and the inhibition of extracellular polysaccharide synthesis, modification of cell morphology coupled with membrane localization of heparin synthase effectively improved the titer of HMW-heparosan to reach 1401 mg/L. Furthermore, the engineered strain produced 7.02 g/L heparosan in fed-batch with a high-molecular weight of 801kDa. These results demonstrate combinatorial optimization of cell factories, especially cell morphology and membrane localization of key enzymes, is efficacious and likely applicable for the production of other biopolymers.