title: Production of D-Glutamate from L-Glutamate with Glutamate Racemase and L-Glutamate Oxidase.
abstract: We studied production of D-glutamate from L-glutamate using a bioreactor consisting of two columns of sequentially connected immobilized glutamate racemase (EC 5.1.1.3, from Bacillus subtilis IFO 3336) and L-glutamate oxidase (EC 1.4.3.11, from Streptomyces sp. X119-6): L-glutamate was racemized by the glutamate racemase column, and then L-glutamate was oxidized by the L-glutamate oxidase column. Consequently only D-glutamate remained, and was easily separated from the α-ketoglutarate formed by anion-exchange chromatography. Both enzymes were highly stabilized by immobilization. The pH and temperature optima of immobilized glutamate racemase (pH 8, 40°C) were similar to those of immobilized L-glutamate oxidase (pH 7, 50°C). Accordingly, we connected the two columns tandemly to do both enzyme reactions under the same conditions. Actually 4.5 μmol of D-glutamate was produced and isolated from 10 μmol of L-glutamate, about 90% of the theoretical yield.
authors.affiliation: a Department of Biotechnology, Faculty of Engineering, Kansai University.|b Kansai University High Technology Research Center.
authors.forename: T
authors.initials: T
authors.lastname: Oikawa
authors.affiliation: a Department of Biotechnology, Faculty of Engineering, Kansai University.
authors.forename: M
authors.initials: M
authors.lastname: Watanabe
authors.affiliation: a Department of Biotechnology, Faculty of Engineering, Kansai University.
authors.forename: H
authors.initials: H
authors.lastname: Makiura
authors.affiliation: c Yamasa Corporation.
authors.forename: H
authors.initials: H
authors.lastname: Kusakabe
authors.affiliation: a Department of Biotechnology, Faculty of Engineering, Kansai University.|b Kansai University High Technology Research Center.
authors.forename: K
authors.initials: K
authors.lastname: Yamade
authors.affiliation: a Department of Biotechnology, Faculty of Engineering, Kansai University.|b Kansai University High Technology Research Center.
authors.forename: K
authors.initials: K
authors.lastname: Soda
keywords: D-glutamate production; L-glutamate oxidase; glutamate racemase