title: Heterologous expression of Escherichia coli fructose-1,6-bisphosphatase in Corynebacterium glutamicum and evaluating the effect on cell growth and L-lysine production.
abstract: Fructose-1,6-bisphosphatase (FBPase), which is mainly used to supply NADPH, has an important role in increasing L-lysine production by Corynebacterium glutamicum. However, C. glutamicum FBPase is negatively regulated at the metabolic level. Strains that overexpressed Escherichia coli fructose-1,6-bisphosphatase in C. glutamicum were constructed, and the effects of heterologous FBPase on cell growth and L-lysine production during growth on glucose, fructose, and sucrose were evaluated. The heterologous fructose-1,6-bisphosphatase is insensitive to fructose 1-phosphate and fructose 2,6-bisphosphate, whereas the homologous fructose-1,6-bisphosphatase is inhibited by fructose 1-phosphate and fructose 2,6-bisphosphate. The relative enzyme activity of heterologous fructose-1,6-bisphosphatase is 90.8% and 89.1% during supplement with 3 mM fructose 1-phosphate and fructose 2,6-bisphosphate, respectively. Phosphoenolpyruvate is an activator of heterologous fructose-1,6-bisphosphatase, whereas the homologous fructose-1,6-bisphosphatase is very sensitive to phosphoenolpyruvate. Overexpression of the heterologous fbp in wild-type C. glutamicum has no effect on L-lysine production, but fructose-1,6-bisphosphatase activities are increased 9- to 13-fold. Overexpression of the heterologous fructose-1,6-bisphosphatase increases L-lysine production in C. glutamicum lysC(T311I) by 57.3% on fructose, 48.7% on sucrose, and 43% on glucose. The dry cell weight (DCW) and maximal specific growth rate (μ) are increased by overexpression of heterologous fbp. A "funnel-cask" diagram is first proposed to explain the synergy between precursors supply and NADPH supply. These results lay a definite theoretical foundation for breeding high L-lysine producers via molecular target.
authors.affiliation: a The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University , WuXi , People's Republic of China.
authors.forename: J Z
authors.initials: JZ
authors.lastname: Xu
authors.forename: J L
authors.initials: JL
authors.lastname: Zhang
authors.forename: Y F
authors.initials: YF
authors.lastname: Guo
authors.forename: Q D
authors.initials: QD
authors.lastname: Jia
authors.forename: W G
authors.initials: WG
authors.lastname: Zhang
mesh_terms: D048230:Corynebacterium glutamicum / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D003470:Culture Media / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D005632:Fructose / Q000378:metabolism; D006597:Fructose-Bisphosphatase / Q000235:genetics* / Q000378:metabolism*; D015870:Gene Expression; D005947:Glucose / Q000378:metabolism; D007218:Industrial Microbiology; D008239:Lysine / Q000378:metabolism*; D013395:Sucrose / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D003470:Culture Media; D005632:Fructose; D013395:Sucrose; D006597:Fructose-Bisphosphatase; D005947:Glucose; D008239:Lysine