A constraint-based modeling approach to reach an improved chemically
defined minimal medium for recombinant antiEpEX-scFv production by
Escherichia coli
Abstract
Increasing demand for recombinant therapeutic proteins highlights the
necessity of their yield improvement. Culture medium formulation is a
popular approach for bioprocess optimization to improve therapeutic
protein production. Constraint-based modeling can empower high-precision
optimization through information on how media compounds affect
metabolism and cell growth. In the current study, a genome-scale
metabolic model (GEMM) of Escherichia coli cells was employed to design
strategies of minimal medium supplementation for higher antiEpEX-scFv
production. Dynamic flux balance analysis of the recombinant E. coli
cell model predicted that ammonium was depleted during the process.
Based on the simulations, three amino acids (Asn, Gln and Arg) were
chosen to be added to the medium to compensate for ammonium depletion.
Experimental validation suggested that the addition of these amino acids
(one-by-one, or in combinations) can indeed improve cell growth and
recombinant protein production. Then, design of experiment was used to
optimize the concentrations of amino acids in the growth medium. About
two-fold increase in the growth rate and total scFv expression level was
observed using this strategy. We conclude that the GEMM-based approach
can provide insights into an effective feeding strategy to improve the
production of recombinant protein in E. coli.