Technical University of Munich, Institute of Biochemical Engineering, Boltzmannstr. 15, 85748 Garching, Germany.
J Biotechnol. 2017 Sep 20;258:92-100. doi: 10.1016/j.jbiotec.2017.06.409. Epub 2017 Jun 20.
Steady state studies in a chemostat enable the control of microbial growth rate at defined reaction conditions. The effects of bacteriophage M13 infection on maximum growth rate of Escherichia coli JM109 were studied in parallel operated chemostats on a milliliter-scale to analyze the steady state kinetics of phage production. The bacteriophage infection led to a decrease in maximum specific growth rate of 15% from 0.74h to 0.63h. Under steady state conditions, a constant cell specific ssDNA formation rate of 0.15±0.004 mg gh was observed, which was independent of the growth rate. Using the estimated kinetic parameters for E. coli infected with bacteriophage M13, the ssDNA concentration in the steady state could be predicted as function of the dilution rate and the glucose concentration in the substrate. Scalability of milliliter-scale data was approved by steady state studies on a liter-scale at a selected dilution rate. An ssDNA space-time yield of 5.7mgLh was achieved with increased glucose concentration in the feed at a dilution rate of 0.3h, which is comparable to established fed-batch fermentation with bacteriophage M13 for ssDNA production.
在恒化器中进行稳态研究可以在定义的反应条件下控制微生物的生长速率。在并行运行的毫升规模恒化器中，研究了噬菌体 M13 感染对大肠杆菌 JM109 最大生长速率的影响，以分析噬菌体生产的稳态动力学。噬菌体感染导致最大比生长速率从 0.74h 降低到 0.63h，降低了 15%。在稳态条件下，观察到细胞特异性 ssDNA 形成速率为 0.15±0.004mggh，与生长速率无关。利用估计的噬菌体感染大肠杆菌的动力学参数，可以预测在选定的稀释率和基质中葡萄糖浓度下，稳态时的 ssDNA 浓度。通过在选定的稀释率下进行升规模的稳态研究，验证了毫升规模数据的可扩展性。在 0.3h 的稀释率下，随着进料中葡萄糖浓度的增加，ssDNA 的时空产率达到 5.7mgLh，与用噬菌体 M13 进行的已建立的补料分批发酵生产 ssDNA 相当。
