title: Intramolecular carbon isotopic composition of monosodium glutamate: biochemical pathways and product source identification.
abstract: Monosodium glutamate (MSG) obtained as trade samples from several manufacturers was studied to determine the range of its intramolecular 13C/12C composition. Although the carbon isotopic composition of the total MSG molecule did not differ among manufacturers in most instances, significant differences were observed in the isotopic composition of the alpha-carboxyl carbon, suggesting that different proprietary strains of industrial microorganisms or MSG purification methods may impart unique isotopic fingerprints upon their products. The 13C depletion of the alpha-carboxyl carbon relative to the rest of the molecule helps constrain the identity of the potential anapleurotic carboxylating enzymes responsible for its fixation.
authors.affiliation: Department of Marine, Earth, and Atmospheric Sciences, Box 8208, North Carolina State University, Raleigh, North Carolina 27695, USA. wsavidge@skio.peachnet.edu
authors.forename: William B
authors.initials: WB
authors.lastname: Savidge
authors.forename: Neal E
authors.initials: NE
authors.lastname: Blair
mesh_terms: D001419:Bacteria / Q000378:metabolism; D002244:Carbon / Q000032:analysis; D002247:Carbon Isotopes / Q000032:analysis*; D019649:Food Industry; D012970:Sodium Glutamate / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D002247:Carbon Isotopes; D002244:Carbon; D012970:Sodium Glutamate