Metabolic Engineering of Escherichia coli for Efficient Production of Pseudouridine

Abstract

Pseudouridine-incorporated mRNA vaccines can enhance protein expression and reduce immunogenicity, leading to a high demand for pseudouridine to be used in mRNA drug production. To achieve the low-cost production of pseudouridine, Escherichia coli was systematically modified to utilize inexpensive raw materials to efficiently produce pseudouridine. First, in the pyrimidine biosynthesis pathway, genes related to the precursor competing pathway and the negative regulator were deleted, which increased pseudouridine production. Second, two critical genes, pseudouridine-5'-phosphate glycosidase (psuG) and phosphatase genes from different bacteria, were screened and employed in various genetic constructs, and the pseudouridine yield of the optical strain increased to 599 mg/L. The accumulation of pseudouridine was further increased by the deletion of pseudouridine catabolism-related genes. Ultimately, the pseudouridine titer in a 5 L bioreactor reached 7.9 g/L, and the yield of pseudouridine on glucose was 0.15 g/g. Overall, a cell factory producing pseudouridine was successfully constructed and showed potential for industrial production.