title: Phosphoenolpyruvate-supply module in Escherichia coli improves N-acetyl-D-neuraminic acid biocatalysis.
abstract: OBJECTIVE
  N-Acetyl-D-neuraminic acid (Neu5Ac) is often synthesized from exogenous N-acetylglucosamine (GlcNAc) and excess pyruvate. We have previously constructed a recombinant Escherichia coli strain for Neu5Ac production using GlcNAc and intracellular phosphoenolpyruvate (PEP) as substrates (Zhu et al. Biotechnol Lett 38:1-9, 2016).
  
  
  RESULTS
  PEP synthesis-related genes, pck and ppsA, were overexpressed within different modes to construct PEP-supply modules, and their effects on Neu5Ac production were investigated. All the PEP-supply modules enhanced Neu5Ac production. For the best module, pCDF-pck-ppsA increased Neu5Ac production to 8.6 ± 0.15 g l-1, compared with 3.6 ± 0.15 g l-1of the original strain. Neu5Ac production was further increased to 15 ± 0.33 g l-1in a 1 l fermenter.
  
  
  CONCLUSIONS
  The PEP-supply module can improve the intracellular PEP supply and enhance Neu5Ac production, which benefited industrial Neu5Ac production.
authors.affiliation: The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
authors.forename: Deqiang
authors.initials: D
authors.lastname: Zhu
authors.affiliation: The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
authors.forename: Jianrong
authors.initials: J
authors.lastname: Wu
authors.affiliation: The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China. xbzhan@yahoo.com.
authors.forename: Xiaobei
authors.initials: X
authors.lastname: Zhan
authors.affiliation: The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhu
authors.affiliation: The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Zheng
authors.affiliation: The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
authors.forename: Minjie
authors.initials: M
authors.lastname: Gao
mesh_terms: D055162:Biocatalysis; D004926:Escherichia coli / Q000378:metabolism*; D010728:Phosphoenolpyruvate / Q000378:metabolism*; D019289:Pyruvic Acid / Q000378:metabolism
chemical_list: D010728:Phosphoenolpyruvate; D019289:Pyruvic Acid
keywords: Biocatalysis; N; Phosphoenolpyruvate-supply; pck; ppsA