title: Metabolic engineering of Escherichia coli for the production of four-, five- and six-carbon lactams.
abstract: Microbial production of chemicals and materials from renewable sources is becoming increasingly important for sustainable chemical industry. Here, we report construction of a new and efficient platform metabolic pathway for the production of four-carbon (butyrolactam), five-carbon (valerolactam) and six-carbon (caprolactam) lactams. This pathway uses ω-amino acids as precursors and comprises two steps. Activation of ω-amino acids catalyzed by the Clostridium propionicum β-alanine CoA transferase (Act) followed by spontaneous cyclization. The pathway operation was validated both in vitro and in vivo. Three metabolically engineered Escherichia coli strains were developed by introducing the newly constructed metabolic pathway followed by systems-level optimization, which resulted in the production of butyrolactam, valerolactam and caprolactam from renewable carbon source. In particular, fed-batch fermentation of the final engineered E. coli strain produced 54.14g/L of butyrolactam in a glucose minimal medium. These results demonstrate the high efficiency of the novel lactam pathway developed in this study.
authors.affiliation: Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 plus program), Institute for the BioCentury, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
authors.forename: Tong Un
authors.initials: TU
authors.lastname: Chae
authors.affiliation: Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 plus program), Institute for the BioCentury, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
authors.forename: Yoo-Sung
authors.initials: YS
authors.lastname: Ko
authors.affiliation: Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 plus program), Institute for the BioCentury, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
authors.forename: Kyu-Sang
authors.initials: KS
authors.lastname: Hwang
authors.affiliation: Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 plus program), Institute for the BioCentury, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea; Bioinformatics Research Center, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea; BioProcess Engineering Research Center, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea. Electronic address: leesy@kaist.ac.kr.
authors.forename: Sang Yup
authors.initials: SY
authors.lastname: Lee
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D003013:Clostridium / Q000201:enzymology / Q000235:genetics*; D015256:Coenzyme A-Transferases / Q000096:biosynthesis / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D007769:Lactams / Q000378:metabolism*; D060847:Metabolic Engineering / Q000379:methods*
chemical_list: D001426:Bacterial Proteins; D007769:Lactams; D015256:Coenzyme A-Transferases
keywords: Butyrolactam; Caprolactam; Lactams; Metabolic engineering; Valerolactam; β-alanine CoA transferase