Abstract: [Objective] This study investigated the production of intracellular triterpenoids in the fungus strain Melanoporia castanea CY-2012 in order to obtain the highest amount of triterpenoids. [Method] The strain CY-2012, collected in Changbai Mountains, was first cultured under 28℃, 150 r·min^-1. Subsequently, the submerged fermentation medium components were optimized through 2 single-factor experiments and one orthogonal experiment of four-variables with three-levels. Furthermore, isopropyl alcohol-ammonium sulfate aqueous two-phase systems were used to extract intracellular triterpenes of mycelia which were obtained under the optimal medium condition, and the extraction technique was optimized through 2 single-factor experiments and an orthogonal experiment of three-variables with three-levels. [Result] The optimal medium components were composed of peeled potatoes 200 g·L^-1, glucose 25.0 g·L^-1, lactose 3.0 g·L^-1, yeast extract 15.0 g·L^-1, MgSO₄ 0.5 g·L^-1, KH₂PO₄ 0.5 g·L^-1, NH₄NO₃ 0.3 g·L^-1, and VB₁ 0.5 g·L^-1. After the fhe fungus was incubated for ten days under 28℃, the mycelium dry weight reached 0.769 g·(100 mL^-1) which was 9.96 times greater than that produced at the initial conditions, and the yield of intracellular triterpenoids reached 14.529 mg·(100 mL^-1) which was 35.52 times greater than that produced at the initial conditions. The best extraction process with the two-phase extracting agent was under 40% isopropyl alcohol, and 0.18 g·mL^-1 ammonium sulfate in water, the mycelia were steeped for 2 hours at room temperature, and the extract was treated with ultrasonic for 35 min, and the triterpenoids extraction rate was 3.65%. [Conclusion] Optimized medium components could substantially boost the yield of total triterpenoids, and optimized isopropyl alcohol-ammonium sulfate aqueous two-phase systems could enhance the triterpenoids extraction rate.

Key words: Melanoporia castanea, triterpenoids, optimization, aqueous two-phase systems, extraction technique