Metabolic engineering of Escherichia coli for the biosynthesis of 2 pyrrolidone
2 Pyrrolidone is a valuable bulk chemical with myriad applications as a solvent, polymer precursor and active pharmaceutical intermediate. A novel 2 pyrrolidone synthase, ORF27, from Streptomyces aizunensis was identified to catalyze the ring closing dehydration of g aminobutyrate. ORF27's tendency to aggregate was resolved by expression at low temperature and fusion to the maltose binding protein (MBP) Recombinant Escherichia coli was metabolically engineered for the production of 2 pyrrolidone from glutamate by expressing both the genes encoding GadB, a glutamate decarboxylase, and ORF27. Incorporation of a GadB mutant lacking H465 and T466, GadB_DHT, improved the efficiency of one pot 2 pyrrolidone biosynthesis in vivo. When the recombinant E. coli strain expressing the E. coli GadB_DHT mutant and the ORF27 MBP fusion was cultured in ZYM 5052 medium containing 9 g/L of l glutamate, 7.7 g/L of l glutamate was converted to 1.1 g/L of 2 pyrrolidone within 31 h, achieving 25% molar yield from the consumed substrate.
Metabolic engineering communications