文献类型：期刊文献

英文题名：Enhanced production of human epidermal growth factor under control of the phoA promoter by acetate-tolerant Escherichia coli DB15 in a chemically defined medium

作者：Zhang, Yanjun[1]; Li, Zhimin[1]; Ye, Qin[1]

机构：[1] State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200-237, China

年份：2010

卷号：15

期号：4

起止页码：626

外文期刊名：Biotechnology and Bioprocess Engineering

收录：EI(收录号：20111613915391)

语种：英文

外文关键词：Chlorine compounds - Gene expression - Escherichia coli - Dissolved oxygen

摘要：The phoA expression system is an efficient one and is successfully used in foreign gene expression. In a previous study, it was found that pH during the expression phase had a significant effect on extracellular hEGF production under control of the phoA promoter by Escherichia coli DA19, an acetate-tolerant strain of E. coli DH5α, in a chemically defined medium, but the level of hEGF production was only 75.5 mg/L. E. coli DB15 is another acetate tolerant mutant of DH5α. In the present study, production of hEGF under control of the phoA promoter by DB15 was further investigated. When transition from the growth phase, where phosphate was abundant, to the expression phase where phosphate was limited, was performed based on cell density, the extracellular hEGF reached 165 mg/L, twice that when transition was based on dissolved oxygen. Furthermore, adding 0.22 g/L of CaCl2 during the growth phase, further increased hEGF production to 228 mg/L, which is 3-fold the level produced by DA19 (pAET-8) cultured in the same medium. ? The Korean Society for Biotechnology and Bioengineering and Springer 2010.