Hajihassan Zahra, Tilko Pouria Gholami, Sadat Seyedeh Mahdieh
Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran.
Pol J Microbiol. 2018;67(3):355-363. doi: 10.21307/pjm-2018-045.
Human nerve growth factor β (β-NGF) is considered a major therapeutic agent for treatment of neurodegenerative diseases. We have previously reported the optimized conditions for β-NGF overproduction in Escherichia coli in a shake-flask culture. In this study the optimal %DO (dissolved oxygen) and post induction temperature values for improved production of β-NGF were found in the bioreactor scale using response surface methodology (RSM) as the most common statistical method. Also, for further enhancement of the yield, different post-induction periods of time were selected for testing. In all experiments, the productivity level and bacterial cell growth were evaluated by western blotting technique and monitoring of absorbance at 600 nm, respectively. Our results indicated that %DO, the post-induction time and temperature have significant effects on the production of β-NGF. After 2 hours of induction, the low post induction temperature of 32°C and 20% DO were used to increase the production of β-NGF in a 5-l bioreactor. Another important result obtained in this study was that the improved β-NGF production was not achieved at highest dry cell weigh or highest cell growth. These results are definitely of importance for industrial β-NGF production.
人神经生长因子β（β-NGF）被认为是治疗神经退行性疾病的主要治疗剂。我们之前已经报道了在摇瓶培养中大肠杆菌中β-NGF过量生产的优化条件。在本研究中，使用响应面法（RSM）这一最常用的统计方法，在生物反应器规模中找到了提高β-NGF产量的最佳溶解氧（%DO）和诱导后温度值。此外，为了进一步提高产量，选择了不同的诱导后时间段进行测试。在所有实验中，分别通过蛋白质印迹技术和监测600nm处的吸光度来评估生产力水平和细菌细胞生长。我们的结果表明，%DO、诱导后时间和温度对β-NGF的生产有显著影响。诱导2小时后，在5升生物反应器中使用32°C的低诱导后温度和20%的溶解氧来提高β-NGF的产量。本研究中获得的另一个重要结果是，在最高干细胞重量或最高细胞生长时并未实现β-NGF产量的提高。这些结果对于工业生产β-NGF肯定具有重要意义。
