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B6db references: 28438014

type Journal Article
authors Lee KW, Shim JM, Yao Z, Kim JA, Kim HJ, Kim JH
title Characterization of a Glutamate Decarboxylase (GAD) from Enterococcus avium M5 Isolated from Jeotgal, a Korean Fermented Seafood
journal J Microbiol Biotechnol
sel selected
ui 28438014
year (2017)
volume 27
number 7
pages 1216-1222
keywords Enterococcus avium; Gamma-aminobutyric acid; gad gene cloning; glutamate decarboxylase; jeotgal
abstract To develop starters for the production of functional foods or materials, lactic acid bacteria producing γ-aminobutyric acid (GABA) were screened from jeotgals, Korean fermented seafoods. One isolate producing a high amount of GABA from monosodium L-glutamate (MSG) was identified as Enterococcus avium by 16S rRNA gene sequencing. E. avium M5 produced 18.47 1.26 mg/ml GABA when incubated for 48 h at 37C in MRS broth with MSG (3% (w/v)). A gadB gene encoding glutamate decarboxylase (GAD) was cloned and overexpressed in E. coli BL21 (DE3) using the pET26b (+) expression vector. Recombinant GAD was purified through a Ni-NTA column and the size was estimated to be 53 kDa by SDS-PAGE. Maximum GAD activity was observed at pH 4.5 and 55C and the activity was dependent on pyridoxal 5'-phosphate. The Km and Vmax values of GAD were 3.26 0.21 mM and 0.0120 0.0001 mM/min, respectively, when MSG was used as a substrate. Enterococcus avium M5 secretes a lot of GABA when grown on MRS with MSG, and the strain is useful for the production of fermented foods containing a high amount of GABA.
last changed 2017/10/11 10:10

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