Lawrence Berkeley National Laboratory
Metabolic engineering of Escherichia coli for the biosynthesis of 2-pyrrolidone
- Author(s): Zhang, J
- Kao, E
- Wang, G
- Baidoo, EEK
- Chen, M
- Keasling, JD
- et al.
Published Web Locationhttp://doi.org/10.1016/j.meteno.2015.11.001
© 2015. 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 γ-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_δHT, improved the efficiency of one-pot 2-pyrrolidone biosynthesis in vivo. When the recombinant E. coli strain expressing the E. coli GadB_δHT 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.