title: Heterologous gshF gene expression in various vector systems in Escherichia coli for enhanced glutathione production.
abstract: Glutathione (GSH), an important bioactive product, is widely used in production of pharmaceuticals and foods. In this study, four different vector systems, pET28a, pUC18, pUC19-P32, and pUC19-Pabb, were applied for expression of gshF, encoding the bifunctional glutathione synthetase of Streptococcus thermophiles. These four constructs were named as pET28a-gshF, pUC18-gshF, pUC19-P32-gshF and pUC19-Pabb-gshF, respectively, and then introduced into Escherichia coli strain BL21(DE3) for further investigation of protein expression and GSH production. The expression levels of the GshF in BL21(pUC19-P32-gshF) and BL21(pUC19-Pabb-gshF) were much lower than those of BL21(pET28a-gshF) and BL21(pUC18-gshF). In the fed-batch fermentation, the GSH accumulated by BL21(pUC18-gshF) reached 15.21 g/L, which was the highest level of GSH biosynthesis ever reported. Although BL21(pUC19-Pabb-gshF) produced less GSH compared to BL21(pUC18-gshF), the final GSH concentration produced by BL21 (pUC19-Pabb-gshF) still accumulated to 5.09 g/L, which indicated the potential application of the constitutive promoter in GSH production.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China. Electronic address: hwu@ecust.edu.cn.
authors.forename: Hui
authors.initials: H
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China; Shanghai Collaborative Innovation Center for Biomanufacturing Technology, 130 Meilong Road, Shanghai 200237, China. Electronic address: lizm@ecust.edu.cn.
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Li
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Ye
mesh_terms: D000975:Antioxidants / Q000032:analysis / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D019149:Bioreactors; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D005285:Fermentation; D005822:Genetic Vectors / Q000235:genetics*; D005978:Glutathione / Q000032:analysis / Q000378:metabolism*; D005981:Glutathione Synthase / Q000235:genetics* / Q000378:metabolism
chemical_list: D000975:Antioxidants; D001426:Bacterial Proteins; D005981:Glutathione Synthase; D005978:Glutathione
keywords: Antioxidant; Bifunctional glutathione synthetase; Escherichia coli; Fed-batch fermentation; Glutathione