Factors influencing excretive production of human epidermal growth factor (hEGF) with recombinant Escherichia coli K12 system

Abstract

Human epidermal growth factor (hEGF) was expressed and excreted into culture medium in an excretory recombinant Escherichia coli system. Conditions for the production of hEGF in this system were investigated. Results showed that the slight reduction of promoter strength improved the stability of plasmid and the production of hEGF in this recombinant system. One favorable MMBL medium for hEGF production was formulated by evaluating the effects of medium components, ampicilin addition and pH. hEGF production was affected obviously by culture conditions, especially fermentation temperature. High temperature (32°C) was very bene®cial for culture process by increasing productivity and reducing the quantity of isopropyl-b-D D-thiogalactopyranoside (IPTG) for suf®cient induction. High cell density and hEGF productivity could be accomplished concomitantly by inducing the culture at middle or late log phase of cell growth. In comparison with the batch process, fed-batch cultivation could improve plasmid stability from ca. 72% to ca. 83%, and increased hEGF productivity by 24.4%. Under all these circumstances, almost all expressed hEGF (³95%) was fully excreted into the culture medium.

Expression of Recombinant Human Epidermal Growth Factor in Escherichia coli and Characterization of its Biological Activity

“…Interferon alpha 2 and 6 were secreted across the cytoplasmic membrane into the periplasmic space of E. coli when the mature protein was fused to the signal peptide of OmpA, a major outer membrane protein of E. coli [10,11]. Similarly, the expressed hEGF could be secreted into the medium quickly and efficiently, because of its lower molecular weight [12].…”

Optimization of an induction strategy for improving interferon‐α2b production in the periplasm of Escherichia coli using response surface methodology

“…On the other hand, higher temperatures might increase the action of host proteases by recognizing the protein conformation [44]. In contrast, a temperature higher than 30 °C was more favourable for some recombinant proteins [45,46]. This might be due to the nature of stability of a particular protein towards the temperature changes during cultivation.…”

Effects of the immobilization of recombinant Escherichia coli on cyclodextrin glucanotransferase (CGTase) excretion and cell viability

“…Conversely, the lower amounts of nitrogen and carbon sources in M9 medium decreased the cell density and CGTase expression, which led to a low level of excretion. Zhinan et al [37] showed that 2 × YT was the best medium for human epidermal growth factor (hEGF) production compared with 14 other media. In studies conducted by Low et al [38] and Kushoo et al [39], TB medium was chosen for further evaluation because the richness of this medium significantly enhances protein expression.…”