Wang J, Chen J, Xu R, Xu Z
School of Bioscience and Bioengineering, Southern China University of Technology, Guangzhou, P. R. China.
Prep Biochem Biotechnol. 2008;38(3):271-81. doi: 10.1080/10826060802165089.
Batch and fed-batch production of recombinant human epidermal growth factor (hEGF) was studied in an E. coli secretary expression system. By using MMBL medium containing 5 g/L glucose, controlling the temperature at 32 degrees C and maintaining the dissolved oxgen level over 20% saturation, a high yield of hEGF (32 mg/L) was obtained after an 18 hr batch cultivation with 0.2 mM IPTG induction at mid-log phase. Three different glucose feeding strategies were employed to further improve hEGF productivity in a bench top fermentor. Compared with the batch results, hEGF yield was improved up to 25.5% or 28.1%, respectively by intermittent or pH-stat glucose feeding, and up to 150% improvement of hEGF production was achieved by constant feeding of 200 g/L glucose solution at a rate of 0.11 mL/min. The effects of further combined feeding with other medium components and inducer on hEGF yield were also examined in the benchtop fermentor. This work is very helpful to further improve the productivity of extracellular hEGF in the recombinant E. coli system.
在大肠杆菌分泌表达系统中研究了重组人表皮生长因子（hEGF）的分批和补料分批生产。通过使用含有5 g/L葡萄糖的MMBL培养基，将温度控制在32℃并保持溶解氧水平超过20%饱和度，在对数中期用0.2 mM IPTG诱导进行18小时分批培养后，获得了高产率的hEGF（32 mg/L）。采用三种不同的葡萄糖补料策略在台式发酵罐中进一步提高hEGF的生产率。与分批培养结果相比，通过间歇或pH值控制葡萄糖补料，hEGF产量分别提高了25.5%或28.1%，通过以0.11 mL/min的速率持续补料200 g/L葡萄糖溶液，hEGF产量提高了150%。还在台式发酵罐中研究了进一步与其他培养基成分和诱导剂联合补料对hEGF产量的影响。这项工作对于进一步提高重组大肠杆菌系统中细胞外hEGF的生产率非常有帮助。
