Shaanxi R&D Center of Biomaterial and Fermentation Engineering, School of Chemical Engineering, Northwest University, Xi'an, People's Republic of China.
Biotechnol Appl Biochem. 2012 Sep-Oct;59(5):330-7. doi: 10.1002/bab.1032. Epub 2012 Sep 13.
To increase the target protein production and reduce acetic acid accumulation during fed-batch cultivation of recombinant Escherichia coli BL21 in a 30-L bioreactor, 12 different models of pulse feeding were performed to evaluate the effect of pulse feeding at different cultivation phases and pulse frequency on cell growth, acetic acid accumulation, and human-like collagen (HLC) synthesis. The results showed that the acetate concentration was kept at a low level (below 0.5 g/L) in all cases when pulse feeding was introduced before induction, whereas the pulse frequency affected cytoactivity significantly through cell growth rate, oxygen uptake rate, carbon dioxide evolution rate, and the synthesis of the target protein. The final biomass and HLC reached 75.46 and 7.26 g/L, respectively, in the model of 8-Sec feedings per 188 Sec. After induction, the pulse frequency had a great effect on HLC synthesis after high-temperature induction; low frequency was adverse to microorganisms. The model of 3-Sec feeding per 27 Sec was best and resulted in the highest biomass and HLC production. Compared to the pseudo-exponential feeding, pulse feeding reduced acetic acid accumulation effectively.
为了提高重组大肠杆菌 BL21 在 30-L 生物反应器中的分批补料培养中的目标蛋白产量并减少乙酸积累，进行了 12 种不同的脉冲进料模型，以评估在不同培养阶段和脉冲频率下进行脉冲进料对细胞生长、乙酸积累和类人胶原蛋白（HLC）合成的影响。结果表明，在诱导前引入脉冲进料时，所有情况下乙酸浓度均保持在低水平（低于 0.5 g/L），而脉冲频率通过细胞生长速率、氧摄取速率、二氧化碳释放速率和目标蛋白的合成对细胞活力有显著影响。在每 188 秒 8 秒进料的模型中，最终生物量和 HLC 分别达到 75.46 和 7.26 g/L。诱导后，高温诱导后脉冲频率对 HLC 合成有很大影响；低频不利于微生物。每 27 秒 3 秒进料的模型效果最佳，产生的生物量和 HLC 产量最高。与拟指数进料相比，脉冲进料能有效地减少乙酸积累。
