title: Efficient production of gamma-aminobutyric acid using Escherichia coli by co-localization of glutamate synthase, glutamate decarboxylase, and GABA transporter.
abstract: Gamma-aminobutyric acid (GABA) is an important bio-product, which is used in pharmaceutical formulations, nutritional supplements, and biopolymer monomer. The traditional GABA process involves the decarboxylation of glutamate. However, the direct production of GABA from glucose is a more efficient process. To construct the recombinant strains of Escherichia coli, a novel synthetic scaffold was introduced. By carrying out the co-localization of glutamate synthase, glutamate decarboxylase, and GABA transporter, we redirected the TCA cycle flux to GABA pathway. The genetically engineered E. coli strain produced 1.08 g/L of GABA from 10 g/L of initial glucose. Thus, with the introduction of a synthetic scaffold, we increased GABA production by 2.2-fold. The final GABA concentration was increased by 21.8% by inactivating competing pathways.
authors.affiliation: Department of Chemical Engineering, University of Ulsan, 93 Daehakro, Nam-gu, Ulsan, 680-749, Republic of Korea.
authors.forename: Van
authors.initials: V
authors.lastname: Dung Pham
authors.affiliation: Department of Chemical Engineering, University of Ulsan, 93 Daehakro, Nam-gu, Ulsan, 680-749, Republic of Korea.
authors.forename: Sivachandiran
authors.initials: S
authors.lastname: Somasundaram
authors.affiliation: Department of Biotechnology and Bioengineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju, 500-757, Republic of Korea.
authors.forename: Seung Hwan
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Environmental Engineering and Energy, Myongji University, San 38-2, Nam-dong, Cheoin-gu, Yongin-si, Gyeonggido, 449-728, Republic of Korea.
authors.forename: Si Jae
authors.initials: SJ
authors.lastname: Park
authors.affiliation: Department of Chemical Engineering, University of Ulsan, 93 Daehakro, Nam-gu, Ulsan, 680-749, Republic of Korea. shhong@ulsan.ac.kr.
authors.forename: Soon Ho
authors.initials: SH
authors.lastname: Hong
mesh_terms: D053898:Biosynthetic Pathways; D002952:Citric Acid Cycle; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D050485:GABA Plasma Membrane Transport Proteins / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D005968:Glutamate Decarboxylase / Q000378:metabolism*; D005970:Glutamate Synthase / Q000378:metabolism*; D008024:Ligands; D060847:Metabolic Engineering; D011485:Protein Binding; D021381:Protein Transport; D058615:Synthetic Biology; D005680:gamma-Aminobutyric Acid / Q000096:biosynthesis*
chemical_list: D050485:GABA Plasma Membrane Transport Proteins; D008024:Ligands; D005680:gamma-Aminobutyric Acid; D005970:Glutamate Synthase; D005968:Glutamate Decarboxylase; D005947:Glucose
keywords: Co-localization; GABA; Protein scaffold; Synthetic biology