Investigation of a Static k_La Measurement Method Using an Optical Dissolved Oxygen Sensor with Fast Response Time

The k(L)a value (Oxygen-transfer coefficient) is widely used as a scale-up indicator for culture tanks, and several methods have been used to measure it. Among them, the static method is very simple because it does not require bacteria cultivation, allows flexible changes in measurement conditions, and facilitates repeated measurements. On the other hand, the conventional galvanic cell dissolved oxygen sensor has a significant response delay, making it impossible to evaluate culture conditions with high k(L)a values such as those used in actual culture. In this study, it was clarified that a high k(L)a of 300 h(-1) or higher can be measured by a static method using an optical dissolved oxygen sensor with a remarkably fast response time. Furthermore, we correlated the results with various k(L)a measurement methods under exactly the same conditions.