Optimizing Medium for Flavonoid-producing Carpesium Macrocephalum Culture

  Objective  Formulation of the medium for Carpesium macrocephalum culture to produce flavonoids was optimized from the one obtained by a previous study.

  Method  Using NT+NAA 1.0 mg·L^-1+0.2 mg·L^-1 6-BA as the base, the medium optimizations were firstly carried out on the macro-elements, NH₄⁺, NO₃^- and K⁺, then the micro-elements, MoO₄^2-, Zn²⁺, BO₃^3-, Co²⁺, Cu²⁺, I^-, and Mn²⁺ and followed by the added 2, 4-D, KT and GA₃. The cellular growth as well as the flavonoids yield in the culture suspension were monitored for evaluation.

  Result  With the optimized addition of the macro- and micro-elements plus KT or GA₃, the flavonoids produced by C. macrocephalum culture significantly increased (P < 0.05), but reduced by the presence of 2, 4-D. The finalized medium consisted of the base with added 15.46 NH₄⁺ mmol·L^-1, NO₃^- 14.10 mmol·L^-1, K⁺ 19.10 mmol·L^-1, MoO₄^2- 3.0 μmol·L^-1, Zn²⁺ 0.06 mmol·L^-1, BO₃^3- 0.4 mmol·L^-1, Co²⁺ 0.2 μmol·L^-1, Cu²⁺ 0.4 μmol·L^-1, I^- 10 μmol·L^-1, Mn²⁺ 0.2 mmol·L^-1, and KT 0.2 mg·L^-1. The resulting flavonoids content in the culture suspension was 2.05%, which was 1.68-fold of control, and the flavonoids yield 517.87 mg·L^-1, which was 1.80-fold of control.

  Conclusion  By further modifying the previously obtained medium, the flavonoids produced from the C. macrocephalum culture significantly increased.