流加不同物质对大肠杆菌DB15(pAET-8)表达人表皮生长因子的影响

摘要

In the process of human epidermal growth factor (hEGF) expression in Escherichia coli DB15 (pAET-8) , phosphorus element was limited during the expression phase, and this affected bacteria metabolism and hEGF expression. It was investigated the effect of feeding different substrate, including phosphate, tryptone and yeast extract, etc. on hEGF expression during the expression phase. Feeding phosphate during the expression phase increased the specific growth rate in the early expression phase, prolonged the cell growth phase and increased the cell concentration, but hEGF production decreased by 57% than the control group. Feeding tryptone, yeast extract separately during the expression phase had no effect on hEGF production. These results indicated that the nucleotide or amino acid synthesis was not the limiting factor to hEGF production, and improving ATP synthesis ability of DB15 (pAET-8) might be the key factor to hEGF expression.%考察了在大肠杆菌DB15(pAET-8)表达人表皮生长因子(hEGF)过程中流加不同的物质——磷酸盐、蛋白胨和酵母抽提物等对人表皮生长因子表达的影响.在表达阶段单独流加磷酸盐虽然增加了表达初期的比生长速率,延长了菌体生长期,提高了菌体浓度,但hEGF产量却比对照组减少了57％.在表达阶段流加蛋白胨或酵母抽提物也未能提高hEGF的表达水平.表明氨基酸或核苷酸合成并不是hEGF表达的限速步骤,提高大肠杆菌DB15 (pAET-8)合成三磷酸腺苷(ATP)的能力或许是提高hEGF表达的关键.