title: A proposed feeding strategy for the overproduction of recombinant proteins in Escherichia coli.
abstract: Different feeding strategies for the production of human interferon-gamma using an isopropyl beta-D-thiogalactoside-inducible expression system in recombinant Escherichia coli BL21(DE3) (plasmid pET3a-ifngamma) were studied. Four fed-batch modes were designed to compare the effect of mu (specific growth rate) on recombinant-protein production, substrate consumption, by-product formation and plasmid stability during pre- and post-chemical induction in high-cell-density cultures of E. coli. It was found that Y(p/s), the product/substrate yield of interferon-gamma was significantly affected by mu throughout the process, but product/biomass yield (Y(p/x)) was influenced by mu at the pre-induction stage. By applying an efficient feeding strategy, in which the mu was maintained at the maximum attainable level, recombinant protein was accumulated up to a level of 60% of the total cell protein and its productivity was increased significantly. In this case, the overall productivities of biomass and recombinant protein were 6.36 g l(-1) h(-1) and 2.1 g l(-1) h(-1) respectively, in comparison with 1.91 g l(-1) h(-1) and 0.16 g l(-1) h(-1) during exponential feeding, in which the specific growth rate was kept constant throughout the entire process.
authors.affiliation: Biotechnology Group, Department of Chemical Engineering, Faculty of Engineering, Tarbiat Modares University, Tehran, Iran.
authors.forename: Valiollah
authors.initials: V
authors.lastname: Babaeipour
authors.forename: Seyed Abbas
authors.initials: SA
authors.lastname: Shojaosadati
authors.forename: Rasoul
authors.initials: R
authors.lastname: Khalilzadeh
authors.forename: Nader
authors.initials: N
authors.lastname: Maghsoudi
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Tabandeh
mesh_terms: D019149:Bioreactors / Q000382:microbiology*; D018929:Cell Culture Techniques / Q000379:methods*; D003470:Culture Media / Q000378:metabolism*; D004926:Escherichia coli / Q000502:physiology*; D011994:Recombinant Proteins / Q000096:biosynthesis*
chemical_list: D003470:Culture Media; D011994:Recombinant Proteins