补料速度对工程菌生长和产物表达的影响研究

通过研究各培养阶段补料速度对温敏启动子控制的rIL-2工程菌E.coliK802(pLY-4)培养密度和rIL-2表达的影响,发现在各培养阶段控制不同的补料速度有利于提高菌密度和rIL-2表达,缩短培养周期。确定了rIL-2工程菌高密度培养方案,三批重复实验,平均菌密度为58OD_(600);菌干重18.0g/L,rIL-2表达水平为42.4％。

Response of Recombinant Escherichia coli Cell Growth and Product Gene Expression to Feeding Rate

Fermentation studies were performed on an Escherichia coli culture that carries a recombinant plasmid composed of an ampicillin-resistant gene, a temperature-regulated PLPR promoter, and an interleukin-2 (IL-2) gene. The objective was to find the effects of feeding strategies on cell density and production of rIL-2. C-source feeding profiles were calculated to maintain specific growth rate. The results showed that cell density could be increased, specific expression level could be raised and culture time could be saved by using different feeding strategies in each culture period. The technology of high-cell-density culture for this recombinant strain was established. In three duplicate cultures, the average of cell density was 58OD600 ,dry cell weight was 18. 0 g/l, rIL-2 expression was 42. 4% of total cell protein.