High cell density fermentation of recombinant Escherichia coli expressing human interferon alpha 1.
A defined medium was developed which, by means of a specific fed-batch mode, allows growth of the recombinant Escherichia coli strain TG1 (pBB210) up to a cell density of 60 g dry weight/l. Apart from glucose and aqueous ammonia fed as carbon and nitrogen sources, it was necessary to supply other nutrients or O2-enriched air. Aqueous ammonia also served for pH control. The pO2 level was kept at 20% saturation via closed-loop controls operating the two output variables of stirrer speed and glucose feeding rate. This fed-batch method prevented significant accumulation of acetate and other metabolic by-products. The recombinant E. coli expressed interferon alpha 1 more efficiently at a lower specific growth rate (muPr approximately 0.15 h-1) than at the maximum specific growth rate (mu max = 0.45 h-1). Therefore, fermentation in the batch phase at mu max was only allowed to continue up to a medium cell density. In the succeeding fed-batch phase, the specific growth rate was reduced to muPr by increasing the stirrer speed according to an empirically developed time scale.
Zentralinstitut für Mikrobiologie und experimentelle Therapie der AdW der DDR, Jena.
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Riesenberg
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Menzel
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Schulz
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Schumann
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Veith
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Zuber
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Knorre
D000641:Ammonia / Q000378:metabolism; D003470:Culture Media; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D005285:Fermentation; D015964:Gene Expression Regulation, Bacterial; D005947:Glucose / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007370:Interferon Type I / Q000096:biosynthesis*; D007700:Kinetics; D010101:Oxygen Consumption; D011994:Recombinant Proteins
D003470:Culture Media; D007370:Interferon Type I; D011994:Recombinant Proteins; D000641:Ammonia; D005947:Glucose