title: Glutamic acid independent production of poly-γ-glutamic acid by Bacillus amyloliquefaciens LL3 and cloning of pgsBCA genes.
abstract: A new glutamic acid independent poly-γ-glutamic acid (γ-PGA) producing strain, which was identified as Bacillus amyloliquefaciens LL3 by analysis of 16S rDNA and gyrase subunit A gene (gyrA), was isolated from fermented food. The product had a molecular weight of 470, 801 and l-glutamate monomer content of 98.47%. The pre-optimal medium, based on single-factor tests and orthogonal design, contained 50 g/L sucrose, 2g/L (NH(4))(2)SO(4), 0.6g/L MgSO(4), and provided well-balanced changes in processing parameters and a γ-PGA yield of 4.36 g/L in 200 L system. The γ-PGA synthetase genes pgsBCA were cloned from LL3, and successfully expressed by pTrcLpgs vector in Escherichia coli JM109, resulting the synthesis of γ-PGA without glutamate. This study demonstrates the designedly improved yield of γ-PGA in 200 L system and the first report of pgsBCA from glutamic acid independent strain, which will benefit the metabolized mechanism investigation and the wide-ranging application of γ-PGA.
authors.affiliation: Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, Nankai University, Tianjin 300071, PR China.
authors.forename: Mingfeng
authors.initials: M
authors.lastname: Cao
authors.forename: Weitao
authors.initials: W
authors.lastname: Geng
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.forename: Cunjiang
authors.initials: C
authors.lastname: Song
authors.forename: Hui
authors.initials: H
authors.lastname: Xie
authors.forename: Wenbin
authors.initials: W
authors.lastname: Guo
authors.forename: Yinghong
authors.initials: Y
authors.lastname: Jin
authors.forename: Shufang
authors.initials: S
authors.lastname: Wang
mesh_terms: D001407:Bacillus / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D001709:Biotechnology / Q000379:methods*; D003001:Cloning, Molecular; D027081:DNA Gyrase / Q000235:genetics; D004926:Escherichia coli; D005285:Fermentation; D010453:Peptide Synthases / Q000235:genetics*; D011099:Polyglutamic Acid / Q000031:analogs & derivatives* / Q000096:biosynthesis; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D012336:RNA, Ribosomal, 16S; C511775:poly(gamma-glutamic acid); D011099:Polyglutamic Acid; D027081:DNA Gyrase; D010453:Peptide Synthases; C445299:gamma-polyglutamic acid synthetase