Improvement of Heterologous Protein Productivity by Controlling Postinduction Specific Growth Rate in Recombinant Escherichia coli under Control of the PL Promoter

• Published in: Biotechnology progress 1998, Vol.14 (4), p.548-553
• Main Authors: Lim, Hyung-Kwon, Jung, Kyung-Hwan
• Format: Article
• Language: English
• Subjects: Bacterial Proteins - biosynthesis; Bacterial Proteins - genetics; Biological and medical sciences; Biotechnology; Cell Culture Techniques - methods; Cell Division - drug effects; Cell Division - genetics; Culture Media - pharmacology; Escherichia coli - genetics; Escherichia coli - growth & development; Escherichia coli - metabolism; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation; Interferon-gamma - biosynthesis; Interferon-gamma - genetics; Methods. Procedures. Technologies; Microbial engineering. Fermentation and microbial culture technology; Promoter Regions, Genetic - genetics; Recombinant Proteins - biosynthesis
• ISSN: 8756-7938; 1520-6033
• DOI: 10.1021/bp980059y

To develop the optimal operational strategy for the PL promoter of interferon (IFN)‐γ‐producing Escherichia coli, some rational medium feeding methods, carried out just after temperature induction to control the postinduction specific growth rate (μi), were designed. Using experimental data from various batch cultures, we correlated μi with specific IFN‐γ production rate (qpi) to find out how μi just after induction affected qpi. It was revealed that sustaining μi above a certain value after induction was the key factor for high‐level production of IFN‐γ. Stepwise and constant‐rate medium feeding, in which the temperature induction was done simultaneously, at the late‐exponential growth phase of batch culture resulted in a dramatic extension of the production period as a result of sustaining μi after temperature induction. These methods led to the overcoming of harsh conditions after temperature induction and the improvement of IFN‐γ productivity. Finally, by both a high‐cell‐density culture using an exponential fed‐batch culture for cell growth and constant‐rate medium feeding after temperature induction for IFN‐γ production, we accomplished an increase in IFN‐γ production by 23‐fold, 7.43 g/L, as compared with that of batch culture.