Abstract
In the culture of red beet hairy root, the red pigment (mainly betanin) was released from the cells into medium when the cells were subjected to the culture condition under O2 starvation by keeping the concentration of dissolved oxygen in medium at 0 ppm. The amount of released pigment increased with increasing time length of O2 starvation during 26 h. However, an O2 starvation time of less than 16 h was employed to shorten the lag time for cell growth resumption after this starvation treatment. An adsorption column with a hydrophobic resin, Sepabeads SP 207 (styrene-divinylbenzene copolymer), was incorporated in a bioreactor system and the long-term culture of hairy root was carried out with repeated operations of cell growth, pigment release and recovery. In the culture with an O2 starvation time of 16 h, an extracellular production rate of pigment of 11.3 × 10–5 kg/(m3-broth·h) was obtained on the average.
