Résumé
Objective To apply the microbial transformation to transforming the total saponins in the fruit of Panax ginseng (SFPG) and preparing ginsenoside compound K (C-K). Methods The four microbial strains m14, m3, m8, and m9 were screened and isolated from the soil in the botanic garden planted for P. ginseng and they were used for the microbial transformation of SFPG to optimize the strains. Taking C-K contents as index the microbial transformation was detected and analyzed by TLC and HPLC. Results The strain m14 was found to transform the SFPG efficiently to C-K at first. The optimal culturing and transformation conditions of m14 were obtained: time, 6 d; temperature, 30 ℃; revolution of cradle, 160 r/min; initial pH value, 5.5; substratum concentration, 120 mg/mL. Under the optimal condition, the content of C-K was 41.65 times as much as before transformation by m14. Conclusion The m14 is the most effective strain among the four fungal strains. It is the new way available for the C-K industrialized production.