Using a kinetic model that considers cell segregation to optimize hEGF expression in fed-batch cultures of recombinant Escherichia coli.
Growth inhibition of recombinant Escherichia coli during the expression of human epidermal growth factor was observed. The recombinant cells could be segregated into three populations based on their cell division and plasmid maintenance abilities: dividing and plasmid-bearing cells, dividing and plasmid-free cells, and viable-but-non-culturable (VBNC) cells. Fed-batch fermentations were performed to investigate the effect of cell segregation on the kinetics of growth and foreign protein production. The results showed that a low concentration of inducer caused weak induction, whereas high levels cause strong induction, resulting in cells segregating into VBNC bacteria and producing a low foreign protein yield. A kinetic model for cell segregation was proposed and its predictions correlated well with experimental data for cell growth and protein expression. The optimal induction strategy could then be predicted by the model, and this prediction was then verified by experimentally deriving the conditions necessary for maximum expression of recombinant protein.
Zheng
Zhi-Yong
ZY
Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou, 310027, People's Republic of China.
Yao
Shan-Jing
SJ
Lin
Dong-Qiang
DQ
D004815:Epidermal Growth Factor / Q000096:biosynthesis* / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development*; D006801:Humans; D007700:Kinetics; D008954:Models, Biological; D011994:Recombinant Proteins / Q000096:biosynthesis* / Q000235:genetics
D011994:Recombinant Proteins; D004815:Epidermal Growth Factor