Quantification of Oxygen Transfer in Test Tubes by Integrated Optical Sensing

• Published in: Journal of microbiology and biotechnology Vol. 14; no. 5; pp. 991 - 995
• Main Authors: Wittmann, Christoph, Schutz, Verena, John, Gernot, Heinzle, Elmar
• Format: Journal Article
• Language: Korean
• Published: 한국미생물생명공학회 30.10.2004; 한국미생물·생명공학회
• Subjects: Gas-liquid mass transfer; K(L)a; minireactor; optical sensor; screening; 생물학; screening; k_L{a}; minireactor; Gas-liquid mass transfer; optical sensor
• ISSN: 1017-7825; 1738-8872

Immobilized sensor spots were applied for online measurement of dissolved $O_2$, in test tubes. Oxygen transport was quantified at varied shaking frequency and filling volumes. The k$_{L}$ a increased with increasing shaking frequency and decreasing filling volume. In non-baffled tubes the maximum $k_{L}a$ value was $70h^{-1}$, equivalent to a maximum $O_2$ transfer capacity of 15mMh^{-1}$. Monitoring of the hydrodynamic profile revealed that the liquid bulk rotated inside the tube with an inclined liquid surface, whereby the angle between the surface and tube wall increased with increasing shaking frequency. The $k_{L}a$ clearly correlated to the surface area. Placement of four baffles into the tubes improved the oxygen transfer up to 3-fold. The highest increase in $k_{L}a$ was observed at high filling volume and high shaking frequency. The maximum $k_{L}a$ in baffled tubes was $100 h^{-1}$.