Biotechnology Letters, Vol.39, No.2, 227-234, 2017
Phosphoenolpyruvate-supply module in Escherichia coli improves N-acetyl-d-neuraminic acid biocatalysis
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). 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(-1) of the original strain. Neu5Ac production was further increased to 15 +/- 0.33 g l(-1) in a 1 l fermenter. The PEP-supply module can improve the intracellular PEP supply and enhance Neu5Ac production, which benefited industrial Neu5Ac production.