title: Production of gamma-aminobutyric acid by Streptococcus salivarius subsp. thermophilus Y2 under submerged fermentation.
abstract: Gamma-aminobutyric acid (GABA), a major inhibitory neurotransmitter in the central nervous system, has several well-known physiological functions and has been applied to the production of many drugs and functional foods. The technology of GABA production via submerged fermentation by Streptococcus salivarius subsp. thermophilus Y2 was investigated in this paper. It indicated that the GABA production was related to the biochemical characteristics of glutamate decarboxylase (GAD) of S. salivarius subsp. thermophilus Y2. After 24 h of fermentation at 37 degrees C, which is the suitable culture conditions for GAD-production, then the culture condition were adjusted to the optimal temperature (40 degrees C) and pH (4.5) for the GAD reaction activity in biotransformation of cells and pyridoxal 5'-phosphate (0.02 mmol/l) were added to the broth at the 48 h, the GABA production was increased up to 1.76-fold, reaching 7984.75 +/- 293.33 mg/l. The strain shows great potential use as a starter for GABA-containing yoghurt, cheese and other functional fermented food productions.
authors.affiliation: College of Food Science and Technology, Nanjing Agricultural University, Nanjing, China.
authors.forename: S-Y
authors.initials: SY
authors.lastname: Yang
authors.forename: F-X
authors.initials: FX
authors.lastname: Lü
authors.forename: Z-X
authors.initials: ZX
authors.lastname: Lu
authors.forename: X-M
authors.initials: XM
authors.lastname: Bie
authors.forename: Y
authors.initials: Y
authors.lastname: Jiao
authors.forename: L-J
authors.initials: LJ
authors.lastname: Sun
authors.forename: B
authors.initials: B
authors.lastname: Yu
mesh_terms: D002851:Chromatography, High Pressure Liquid; D003470:Culture Media; D005285:Fermentation; D005968:Glutamate Decarboxylase / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D011732:Pyridoxal Phosphate / Q000494:pharmacology; D012970:Sodium Glutamate / Q000494:pharmacology; D013291:Streptococcus / Q000187:drug effects / Q000378:metabolism*; D013696:Temperature; D013997:Time Factors; D005680:gamma-Aminobutyric Acid / Q000096:biosynthesis* / Q000378:metabolism
chemical_list: D003470:Culture Media; D005680:gamma-Aminobutyric Acid; D011732:Pyridoxal Phosphate; D005968:Glutamate Decarboxylase; D012970:Sodium Glutamate