Optimization of culture conditions for gamma-aminobutyric acid production by newly identified <i>Pediococcus pentosaceus</i> MN12 isolated from ‘mam nem’, a fermented fish sauce
Đỗ Thị Bích Thủy, An Tien Nguyen, Kuan Shiong Khoo, Kit Wayne Chew, Margo Cnockaert, Peter Vandamme, Yeek‐Chia Ho, Nguyễn Đức Huy, H. Hernández‐Cocoletzi, Pau Loke Show
Abstract
This study was aimed to identify and optimize the culture conditions for gamma-aminobutyric acid (GABA) production by a lactic acid bacterium strain isolated from mam nem, a fermented fish sauce. Among the six isolates obtained from mam nem, the MN12 had the most potent GABA-producing capability. The strain was then identified to be Pedioccocus pentosaceus by employing MALDI-TOF-MS and phenylalanyl-tRNA synthase sequencing methods. The initial cell density of 5.106 CFU/mL, monosodium glutamate concentration of 60 mM, initial pH of 7, temperature of 45°C and cultivation time of 72 h were found to be the optimal culture conditions for highest production of GABA, reaching 27.9 ± 0.42 mM, by this strain. The cultivation conditions for GABA production by P. pentosaceus MN12 have been successfully optimized, providing a foundation for the development of fermented foods enriched with GABA.