Chen Huaxin, Jiang Peng, Li Fuchao, Wu Haizhen
a Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences , Qingdao , China.
Prep Biochem Biotechnol. 2015;45(7):730-41. doi: 10.1080/10826068.2014.943374.
A stable fluorescent holo-β-allophycocyanin (holo-ApcB) was produced by metabolically engineered Escherichia coli. The E. coli cells harbored two plasmids for expression of five genes that were involved in the holo-ApcB production. Response surface methodology was employed to investigate the individual and interactive effects of four variables, i.e., initial pH of culture medium, IPTG concentration, post-induction temperature, and induction start time, on holo-ApcB production by E. coli. The experimental results showed that the IPTG concentration, postinduction temperature, and induction start time had significant individual effects on holo-ApcB production. A significant interactive effect was also found between the initial pH of culture and induction start time. The maximum holo-ApcB production of 45.3 mg/L was predicted under the following optimized culture conditions: a postinduction temperature of 28.4°C, initial pH of culture of 7.3, IPTG concentration of 1.1 mM, and postinduction time of 66 min. Holo-ApcB production under the optimized culture conditions increased 5.8-fold, compared with that under the nonoptimized conditions. Response surface methodology proved to be a valuable tool for optimization of holo-ApcB production by metabolically engineered E. coli.
通过代谢工程改造的大肠杆菌产生了一种稳定的荧光全藻蓝蛋白（全ApcB）。大肠杆菌细胞携带两个质粒用于表达参与全ApcB生产的五个基因。采用响应面法研究了四个变量，即培养基初始pH值、IPTG浓度、诱导后温度和诱导起始时间，对大肠杆菌生产全ApcB的单独和交互作用。实验结果表明，IPTG浓度、诱导后温度和诱导起始时间对全ApcB的生产有显著的单独影响。还发现培养基初始pH值和诱导起始时间之间存在显著的交互作用。在以下优化培养条件下预测全ApcB的最大产量为45.3mg/L：诱导后温度28.4°C、培养基初始pH值7.3、IPTG浓度1.1mM和诱导后时间66分钟。与未优化条件相比，优化培养条件下全ApcB的产量提高了5.8倍。响应面法被证明是优化代谢工程改造的大肠杆菌生产全ApcB的一种有价值的工具。
