Overexpression and optimization of glutamate decarboxylase in L actobacillus plantarum Taj‐Apis 362 for high gamma‐aminobutyric acid production

Autor: Mohd Yazid Abd Manap, Abdulkarim Sabo Mohammed, Afshin Ebrahimpour, Raha Abdul Rahim, Nazamid Saari, Ali Baradaran, Naser Tajabadi, Fatimah Abu Bakar
Rok vydání: 2015
Předmět:
Zdroj: Microbial Biotechnology. 8:623-632
ISSN: 1751-7915
Popis: Gamma-aminobutyric acid (GABA) is an important bioactive compound biosynthesized by microorganisms through decarboxylation of glutamate by glutamate decarboxylase (GAD). In this study, a full-length GAD gene was obtained by cloning the template deoxyribonucleic acid to pTZ57R/T vector. The open reading frame of the GAD gene showed the cloned gene was composed of 1410 nucleotides and encoded a 469 amino acids protein. To improve the GABA-production, the GAD gene was cloned into pMG36e-LbGAD, and then expressed in Lactobacillus plantarum Taj-Apis362 cells. The overexpression was confirmed by SDS-PAGE and GAD activity, showing a 53 KDa protein with the enzyme activity increased by sevenfold compared with the original GAD activity. The optimal fermentation conditions for GABA production established using response surface methodology were at glutamic acid concentration of 497.973 mM, temperature 36°C, pH 5.31 and time 60 h. Under the conditions, maximum GABA concentration obtained (11.09 mM) was comparable with the predicted value by the model at 11.23 mM. To our knowledge, this is the first report of successful cloning (clone-back) and overexpression of the LbGAD gene from L. plantarum to L. plantarum cells. The recombinant Lactobacillus could be used as a starter culture for direct incorporation into a food system during fermentation for production of GABA-rich products.
Databáze: OpenAIRE