Improvement of γ-aminobutyric acid (GABA) production using cell entrapment of Lactobacillus brevis GABA 057

GABA (gamma-aminobutyric acid) is the principal inhibitory neurotransmitter in the brain. For the efficient production of GABA, a semicontinuous cell entrapment system using Lactobacillus brevis GABA 057 was optimized, including the Substrate concentration, bead-stabilizing additives, and reaction conditions. The converted monosodium glutamate (MSG), which was added as a substrate for glutamic acid decarboxylase (GAD), increased from 2% (w/v) to 12% (w/v). The addition of isomaltooligosaccharide to the alginate beads also increased the stability of the entrapped L. brevis and GABA productivity. Consequently, when optimal conditions were applied, Lip to 223 mM GABA could be produced from 534 mM MSG after 48 h of reaction by using alginate-bead-encapsulated L. brevis GABA 057.