On the influence of overexpression of phosphoenolpyruvate carboxykinase in Streptomyces lividans on growth and production of human tumour necrosis factor-alpha.
Streptomyces lividans has shown potential as an expression system for heterologous proteins. Overexpression of proteic factors important for heterologous protein production is a valuable approach to improve yields of such proteins. Comparative transcriptomic analysis revealed that several genes were differentially expressed in strains involved in heterologous protein production. For instance, the gene-encoding phosphoenolpyruvate carboxykinase (pepck) showed a significant twofold change in recombinant S. lividans producing human tumour necrosis factor-alpha (hTNF-α). The effect of pepck overexpression on S. lividans TK24 and its hTNF-α producing recombinant was thus investigated in bench-top fermenters. Results obtained revealed that pepck overexpression resulted into a twofold increase in specific PEPCK activity during growth. This overexpression is correlated with slower growth rate, reduced excretion of pyruvate and less alkalinisation of the growth medium when compared with the control strain. After 26 h of fermentation, hTNF-α yields were enhanced (up to 1.7-fold) in the pepck-overexpressing S. lividans TK24, demonstrating that this metabolic engineering approach is indeed promising for heterologous protein production.
Chemical and Biochemical Process Technology and Control Section (BioTeC), Department of Chemical Engineering, Katholieke Universiteit Leuven, Willem de Croylaan 46, 3001, Leuven, Belgium.
Ivan
I
Lule
Bárbara
B
Maldonado
Pieter-Jan
PJ
D'Huys
Lieve
L
Van Mellaert
Jan
J
Van Impe
Kristel
K
Bernaerts
Jozef
J
Anné
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D060847:Metabolic Engineering; D019764:Phosphoenolpyruvate Carboxykinase (ATP) / Q000235:genetics* / Q000378:metabolism; D048372:Streptomyces coelicolor / Q000201:enzymology* / Q000235:genetics; D048170:Streptomyces lividans / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000235:genetics*
D001426:Bacterial Proteins; D014409:Tumor Necrosis Factor-alpha; D019764:Phosphoenolpyruvate Carboxykinase (ATP)