title: Robust production of gamma-amino butyric acid using recombinant Corynebacterium glutamicum expressing glutamate decarboxylase from Escherichia coli.
abstract: Gamma-amino butyric acid (GABA) is a component of pharmaceuticals, functional foods, and the biodegradable plastic polyamide 4. Here, we report a simple and robust system to produce GABA from glucose using the recombinant Corynebacterium glutamicum strain GAD, which expresses GadB, a glutamate decarboxylase encoded by the gadB gene of Escherichia coli W3110. As confirmed by HPLC analysis, GABA fermentation by C. glutamicum GAD cultured at 30°C in GABA Production 1 (GP1) medium containing 50 g/L glucose without the addition of glutamate yielded 8.07 ± 1.53 g/L extracellular GABA after 96 h. Addition of 0.1mM pyridoxal 5'-phosphate (PLP) was found to enhance the production of GABA, whereas Tween 40 was unnecessary for GABA fermentation. Using the optimized GABA Production 2 (GP2) medium, which contained 50 g/L glucose and 0.1mM PLP, fermentation was performed in a flask at 30°C with 10% (v/v) seed culture of C. glutamicum GAD. GABA was produced in the culture supernatant with a yield of 12.37 ± 0.88 g/L after 72 h with a space-time yield of 0.172 g/L/h, which is the highest yield obtained to date for GABA from fermentation with glucose as a main carbon source.
authors: Department of Chemical Science and Engineering, Graduate School of Engineering, Graduate School of Science and Technology, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe 657-8501, Japan.
authors: Chihiro
authors: C
authors: Takahashi
authors: Junki
authors: J
authors: Shirakawa
authors: Takeyuki
authors: T
authors: Tsuchidate
authors: Naoko
authors: N
authors: Okai
authors: Kazuki
authors: K
authors: Hatada
authors: Hideki
authors: H
authors: Nakayama
authors: Toshihiro
authors: T
authors: Tateno
authors: Chiaki
authors: C
authors: Ogino
authors: Akihiko
authors: A
authors: Kondo
mesh_terms: D001709:Biotechnology / Q000379:methods*; D048230:Corynebacterium glutamicum / Q000201:enzymology* / Q000235:genetics*; D003470:Culture Media; D004926:Escherichia coli / Q000378:metabolism; D005285:Fermentation; D005818:Genetic Engineering; D005968:Glutamate Decarboxylase / Q000235:genetics / Q000378:metabolism*; D011732:Pyridoxal Phosphate / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000096:biosynthesis*
chemical_list: D003470:Culture Media; D011994:Recombinant Proteins; D005680:gamma-Aminobutyric Acid; D011732:Pyridoxal Phosphate; D005968:Glutamate Decarboxylase