Departamento de Engenharia Química, Escola Politécnica, USP, Brazil.
Biotechnol J. 2011 Dec;6(12):1497-503. doi: 10.1002/biot.201000273. Epub 2011 Jun 7.
Monitoring the specific respiration rate (Q(O2)) is a valuable tool to evaluate cell growth and physiology. However, for low Q(O2) values the accuracy may depend on the measurement methodology, as it is the case in animal cell culture. The widely used "Dynamic Method" imposes serious difficulties concerning oxygen transfer cancellation, especially through membrane oxygenation. This paper presents an improved procedure to this method, through an automated control of the gas inlet composition that can minimize the residual oxygen transfer driving force during the Q(O2) measurement phase. The improved technique was applied to animal cell cultivation, particularly three recombinant S2 (Drosophila melanogaster) insect cell lines grown in a membrane aeration bioreactor. The average measurements of the proposed method reached 98% of stationary liquid phase balance method, taken as a reference, compared to 21% when the traditional method was used. Furthermore, this methodology does not require knowledge of the volumetric transfer coefficient k(L)a, which may vary during growth.
监测特定的耗氧率（Q(O2))是评估细胞生长和生理的有价值的工具。然而，对于低 Q(O2)值，准确性可能取决于测量方法，就像动物细胞培养一样。广泛使用的“动态方法”在氧传递消除方面带来了严重的困难，特别是通过膜氧合。本文提出了一种改进的方法，通过自动控制气体入口成分，可以在 Q(O2)测量阶段最小化残余氧传递驱动力。改进的技术应用于动物细胞培养，特别是在膜曝气生物反应器中生长的三种重组 S2（黑腹果蝇）昆虫细胞系。与传统方法相比，当使用建议的方法时，与作为参考的静止液相平衡方法相比，平均测量值达到 98%，而当使用传统方法时，平均测量值仅为 21%。此外，该方法不需要了解体积传递系数 k(L)a，该系数在生长过程中可能会发生变化。
