Measurement of Cell Mass in Bioreactor Using Ultrasonic Technique

• Published in: Shokubutsu Kojo Gakkaishi Vol. 6; no. 2; pp. 153 - 160
• Main Authors: TORII, Toru, HO, Kang Chang, OKAMOTO, Tuguo, KITANI, Osamu, TAKAYAMA, Shinsaku, NAKAZONO, Atsuyuki
• Format: Journal Article
• Language: Japanese
• Published: JAPANESE SOCIETY OF AGRICULTURAL, BIOLOGICAL AND ENVIRONMENTAL ENGINEERS AND SCIENTISTS 01.06.1994
• ISSN: 0918-6638; 1880-3555
• DOI: 10.2525/jshita.6.153

Mass culture of plant cell and tissues in a bioreactor are widely used for production of plant metabolites or seedlings. Packed Cell Volume (PCV) and Optical Density (OD) are used for off-line measurement, and Electric Conductivity (EC) and pH are used for on-line measurement of growth rate in bioreactors. In these measurement, the samples are derived from a part of a reactor, and these sample may not indicate the actual status of bioreactor, because the growth rate may change in height or radius of bioreactor. An ultrasonic technique was used to measure the growth rate in a bioreactor.The material used were plant cell of Rice plant (Oryza sativa), and adventive root of Atropa belladonna. The frequency of ultrasonic sensors were 0.5, 1, 2, 3, 5, and 7 MHz. It was found that the attenuation of ultrasonic wave propagated through the bioreactor had linear relation with the growth rate and that the stronger attenuations were measured in higher frequencies. The velocity of waves were almost constant with the growth rate. A simple model using a wave equation was used to simulate the attenuation of ultrasonic wave in the bioreactor, and the results showed good agreement with the experiment. The ultrasonic wave can propagate across the bioreactor, and it seems that the results correspond to the actual status of the bioreactor.