An acetate-tolerant mutant of Escherichia coli DH5α, DA19, was used for secretory production of human epidermal growth factor （hEGF） whose expression was under the control of phoA promoter. The recombinant cells we...An acetate-tolerant mutant of Escherichia coli DH5α, DA19, was used for secretory production of human epidermal growth factor （hEGF） whose expression was under the control of phoA promoter. The recombinant cells were cultured in a chemically defined medium, and glucose was added at different specific provision rates during the growth and expression phases. It was found that pH had a significant effect on the extracellular hEGF production. The extracellular hEGF concentration was 75.5mg·L^-1, 5.2-fold of the level reached at pH 7.0, even though more acetate was produced. Nitrogen source was limited in the later growth phase. Supplementation of ammonium promoted the consumption of phosphate and reduced the time to exhaust phosphate, but the extracellular hEGF production was similar to that without supplementation of ammonium.展开更多
基金the National High Technology Research and Development Program of China(863 Program,2002AA217021).
文摘An acetate-tolerant mutant of Escherichia coli DH5α, DA19, was used for secretory production of human epidermal growth factor （hEGF） whose expression was under the control of phoA promoter. The recombinant cells were cultured in a chemically defined medium, and glucose was added at different specific provision rates during the growth and expression phases. It was found that pH had a significant effect on the extracellular hEGF production. The extracellular hEGF concentration was 75.5mg·L^-1, 5.2-fold of the level reached at pH 7.0, even though more acetate was produced. Nitrogen source was limited in the later growth phase. Supplementation of ammonium promoted the consumption of phosphate and reduced the time to exhaust phosphate, but the extracellular hEGF production was similar to that without supplementation of ammonium.
