The authors developed a new method for the large-scale root culture of Bupleurum falcatum L., which is important for medicines and cosmetics. The cultured roots transplanted in fresh medium containing 3-indolebutyric acid(IBA)(4∼8 mg/L)generated new roots, which highly accumulated saikosaponin a and saikosaponin d(SSa/d). On the other hand, the originally transplanted parts contained a trace amount of SSa/d, due to a possible root function loss judged from severe swelling of their cortex cells. Sugars strongly affected the root generation and suppressed the rooting in a dose dependent manner, even at a conventional concentration of 2-3%. The early growth was optimal with 1% sucrose, although the root growth gradually declined after 2 weeks due to lack of energy. The highest yield of SSa/d after 8 weeks culture was 200 mg/L when 4% sucrose was used. On the basis of this finding, the authors developed a two step-culture method, which allowed new roots to be generated during 2 weeks with 1% sucrose and to grow with 6% sucrose after the first 2 weeks. Approximately 800 mg/L SSa/d was formed to accumulate in the roots after 8 week-culture. Bubble column reactor was found to be a simple and efficient system for root culture in 20 L scale with an adequate sparger generating small bubbles. Further scale up was investigated by modifying the internal structure of the reactor for the industrial culturing of roots. To avoid root flocculation, a bottom perforated-plate and draft tube were installed as a partitioning device separating the culturing area(outside the draft tube)from the aeration area(inside the draft tube). This simple modified airlift reactor yielded 500-600 mg/L SSa/d at 200-L scale.

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