Characterization of Glutamate Decarboxylase (GAD) from Lactobacillus sakei A156 Isolated from Jeot-gal.
J Microbiol Biotechnol
; 25(5): 696-703, 2015 May.
Article
en En
| MEDLINE
| ID: mdl-25791853
ABSTRACT
A gamma-aminobutyric acid (GABA)-producing microorganism was isolated from jeot-gal (anchovy), a Korean fermented seafood. The isolate, A156, produced GABA profusely when incubated in MRS broth with monosodium glutamate (3% (w/v)) at 37°C for 48 h. A156 was identified as Lactobacillus sakei by 16S rRNA gene sequencing. The GABA conversion yield was 86% as determined by GABase enzyme assay. The gadB gene encoding glutamate decarboxylase (GAD) was cloned by PCR. gadC encoding a glutamate/GABA antiporter was located immediately upstream of gadB. The operon structure of gadCB was confirmed by RT-PCR. gadB was overexpressed in Escherichia coli BL21(DE3) and recombinant GAD was purified. The purified GAD was 54.4 kDa in size by SDS-PAGE. Maximum GAD activity was observed at pH 5.0 and 55°C and the activity was dependent on pyridoxal 5'-phosphate. The Km and Vmax of GAD were 0.045 mM and 0.011 mM/min, respectively, when glutamate was used as the substrate.
Buscar en Google
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas Bacterianas
/
Alimentos Marinos
/
Glutamato Descarboxilasa
/
Lactobacillus
País/Región como asunto:
Asia
Idioma:
En
Revista:
J Microbiol Biotechnol
Año:
2015
Tipo del documento:
Article