Deqiang Zhu1, Jianrong Wu1, Xiaobei Zhan2, Li Zhu1, Zhiyong Zheng1, Minjie Gao1. 1. The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China. 2. The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China. xbzhan@yahoo.com.
Abstract
OBJECTIVES: 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-1 of the original strain. Neu5Ac production was further increased to 15 ± 0.33 g l-1 in a 1 l fermenter. CONCLUSIONS: The PEP-supply module can improve the intracellular PEP supply and enhance Neu5Ac production, which benefited industrial Neu5Ac production.
OBJECTIVES: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-1 of the original strain. Neu5Ac production was further increased to 15 ± 0.33 g l-1 in a 1 l fermenter. CONCLUSIONS: The PEP-supply module can improve the intracellular PEP supply and enhance Neu5Ac production, which benefited industrial Neu5Ac production.