title: Large-scale production of saikosaponins through root culturing of Bupleurum falcatum L. using modified airlift reactors.
abstract: Modification of internal configuration of a bubble column, airlift and stirred tank reactor (10-200 L) was made for root cultures of Bupleurum falcatum L. Agitation with an impeller covered with partition mesh was ineffective for a 10-L modified reactor, because it caused intensive foaming and subsequent overflow of the culture medium even at a low rotation speed of 50 rpm and a low aeration rate of 0.1 vvm (volume per volume of medium). In contrast, efficient aeration through a ceramic sparger placed at the bottom of a 20-L bubble column reactor yielded approximately 25 g/L of dry roots and 500 mg/L of saikosaponin-a and saikosaponin-d over 42 days. On a 200-L scale, however, the roots became flocculated under the upper perforated plate initially positioned near the middle of the reactor, forming a firm disk of roots and a large empty space between the disk and the medium. Thus, the roots had poor contact with the medium, which severely suppressed their growth. To avoid this 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). The draft tube was made of a stainless steel mesh rather than a solid material, and the tube greatly increased the root yield in the 20-L reactor. This configuration was successfully applied at the 200-L scale, yielding 500-600 mg/L of saikosaponin-a and saikosaponin-d over 56 days.
authors.affiliation: Shiseido Research Center, Shiseido Co., Ltd., 2-2-1 Hayabuchi, Tsuzuki-ku, Yokohama 224-8558, Japan. ken.kusakari@to.shiseido.co.jp
authors.forename: Ken
authors.initials: K
authors.lastname: Kusakari
authors.forename: Mineyuki
authors.initials: M
authors.lastname: Yokoyama
authors.forename: Shinji
authors.initials: S
authors.lastname: Inomata
authors.forename: Yoko
authors.initials: Y
authors.lastname: Gozu
authors.forename: Chika
authors.initials: C
authors.lastname: Katagiri
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Sugimoto
mesh_terms: D019149:Bioreactors; D029972:Bupleurum / Q000254:growth & development / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D009828:Oleanolic Acid / Q000031:analogs & derivatives* / Q000096:biosynthesis; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism*; D012503:Saponins / Q000096:biosynthesis*; D046509:Tissue Culture Techniques / Q000295:instrumentation / Q000379:methods*
chemical_list: D003470:Culture Media; D012503:Saponins; D009828:Oleanolic Acid; C025759:saikosaponin D