title: Vector promoters used in Klebsiella pneumoniae.
abstract: Much effort has been devoted to the metabolic engineering of Klebsiella pneumoniae; however, our knowledge of the actual expression level of promoters used in K. pneumoniae is limited. In this study, the expression levels of three promoters were compared systematically by using the lacZ reporter gene with different carbon sources in K. pneumoniae. The results showed that, although promoters PT5 and Ptac designed for Escherichia coli were functional, PT5 appeared more efficient and the induction/repression ratio of Ptac was decreased extremely in K. pneumoniae. The basal level of Ptac for lacZ expression reached 396.5 U/mg, which was 9.5-fold higher compared with PT5 in LB medium, indicating Ptac can be used as an efficient "constitutive" promoter as well as an efficient induced promoter in K. pneumoniae. In different carbon sources medium, a newly constructed endogenous constitutive Pbud proved to be a stable and weak promoter. On the basis of our data, a set of Pbud and Ptac promoters could meet the broad range (about 1,000 orders of magnitude) of gene expression needed for engineered K. pneumoniae in glycerol-based medium.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China.
authors.forename: Chengqian
authors.initials: C
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Lin
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China.
authors.forename: Jingkang
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China.
authors.forename: Shuilin
authors.initials: S
authors.lastname: Fu
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China. gongheng@ecust.edu.cn.
authors.forename: Heng
authors.initials: H
authors.lastname: Gong
mesh_terms: D018929:Cell Culture Techniques; D004926:Escherichia coli / Q000235:genetics; D017930:Genes, Reporter / Q000235:genetics; D005822:Genetic Vectors / Q000235:genetics*; D005947:Glucose / Q000494:pharmacology; D005990:Glycerol / Q000494:pharmacology; D007711:Klebsiella pneumoniae / Q000166:cytology / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D007763:Lac Operon / Q000235:genetics; D060847:Metabolic Engineering / Q000379:methods*; D011401:Promoter Regions, Genetic / Q000235:genetics*
chemical_list: D005947:Glucose; D005990:Glycerol
keywords: Klebsiella pneumoniae; LacZ reporter gene; gene expression; metabolic engineering; promoter
  