1997 Volume 30 Issue 6 Pages 1070-1075
The influence of liquid flow on the growth of red beet hairy roots is investigated by using a single column reactor operated at 25 °C under a fixed value of superficial velocity of medium. In the cultures of the hairy roots for 172–190 h, average growth rates of 2.8 × 10–2, 1.6 × 10–2 and 0.98 × 10–2 kg/(m3·h) are obtained at superficial velocities of 4.2 × 10–3, 7.8 × 10–3 and 11.1 × 10–3 m/s, respectively. Using the packed column with the hairy roots at void fractions of 0.49 to 0.71, it is found that pressure drop through the root bed increases with an increase in superficial velocity of medium elevated up to about 14 × 10–3 m/s. The effective diameter of the hairy roots is estimated at 1.5 × 10–4 m, considering the root hairs found on the surfaces of the main roots. Pressure drop through the root bed in the column can be correlated with superficial velocity of the medium by using an extended Ergun’s equation expressed in terms of effective diameter of the hairy roots and void fraction in the bed. When the hairy roots are kept for 50 h in the column under pressure drop values of 8.4 × 103 to 3.1 × 104 Pa/m, the reduction in viability of growing points at the hairy root tips is observed with increasing pressure drop in the range.
