title: Expression of glr gene encoding glutamate racemase in Bacillus licheniformis WX-02 and its regulatory effects on synthesis of poly-γ-glutamic acid.
abstract: The glr gene, which encodes glutamate racemase involved in the conversion of L-glutamic acid to its D-isomer, was cloned and expressed in Bacillus licheniformis WX-02. Overexpression of the glr gene not only increased the production of poly-γ-glutamic acid (γ-PGA) by 22.5% but also increased the proportion of D-glutamate in γ-PGA from 77 to 85%. The activity of glutamate racemase was higher than in the original strain throughout cultivation. This is the first report that overexpression of the glr gene could enhance the L- and D-glutamate conversion in B. licheniformis WX-02 and increase the proportion of D-glutamate in γ-PGA and the yield of γ-PGA.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China.
authors.forename: Feng
authors.initials: F
authors.lastname: Jiang
authors.forename: Gaofu
authors.initials: G
authors.lastname: Qi
authors.forename: Zhixia
authors.initials: Z
authors.lastname: Ji
authors.forename: Shuling
authors.initials: S
authors.lastname: Zhang
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.forename: Xin
authors.initials: X
authors.lastname: Ma
authors.forename: Shouwen
authors.initials: S
authors.lastname: Chen
mesh_terms: D000591:Amino Acid Isomerases / Q000235:genetics* / Q000378:metabolism*; D001407:Bacillus / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D015870:Gene Expression; D011099:Polyglutamic Acid / Q000096:biosynthesis*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D011099:Polyglutamic Acid; D000591:Amino Acid Isomerases; C062292:glutamate racemase