Effect of modulated glucose uptake on high-level recombinant protein production in a dense Escherichia coli culture.
Methyl alpha-glucoside (alpha-MG) is a metabolically inert glucose analog sharing the same phosphotransferase system with glucose. The potential of using this compound, which acts as a nontoxic competitive inhibitor, to modulate glucose uptake and subsequently reduce the acetate accumulation rate was investigated. In a complex medium, no significant effect on the growth rate was observed when the alpha-MG to glucose ratio was low. The effect of alpha-MG supplementation on the production of a model recombinant protein, CadA-beta-galactosidase, under the regulation of a pH-inducible promoter in a batch culture was also examined. It was observed that the amount of acetate accumulation was drastically reduced in the presence of alpha-MG. More importantly, recombinant protein productivity was significantly improved. A very high volumetric productivity of approximately 1.6 g/L recombinant protein in a dense culture with an OD600 of 35 was obtained in a simple batch fermentation. Even at this high cell density, the specific protein productivity was maintained at a high level and was estimated to account for about 40% of the total cellular protein.
Chou
C H
CH
Department of Chemical Engineering, Rice University, Houston, Texas 77251-1892.
Bennett
G N
GN
San
K Y
KY
D001426:Bacterial Proteins / Q000096:biosynthesis*; D001709:Biotechnology / Q000379:methods; D003470:Culture Media; D004926:Escherichia coli / Q000187:drug effects* / Q000378:metabolism*; D005285:Fermentation; D005947:Glucose / Q000493:pharmacokinetics*; D008757:Methylglucosides / Q000493:pharmacokinetics / Q000494:pharmacology*; D011994:Recombinant Proteins / Q000096:biosynthesis
D001426:Bacterial Proteins; D003470:Culture Media; D008757:Methylglucosides; D011994:Recombinant Proteins; C027020:methylglucoside; D005947:Glucose