目的 探索红曲霉对人参的固态发酵工艺，将人参中部分主要人参皂苷转化为生物活性更强的稀有人参皂苷Rg₃（Rg₃）。方法 采用静止暗培养方法进行微生物发酵；香草醛-冰醋酸法测定发酵前后人参总皂苷含量；HPLC法测定发酵前后Rg₃含量。结果 红曲霉发酵人参的最优工艺参数为发酵时间6 d、发酵温度32℃、发酵pH 7.0、基质含水量50%。发酵6 d时，发酵产物人参总皂苷质量分数增加40%，Rg₃质量分数为6.047 mg/g，是未发酵人参的2.3倍。最终根据单体皂苷含量随发酵时间的变化趋势，推断稀有皂苷Rg₃的转化路径为人参皂苷Rb₁或Rb₂→Rd→Rg₃。结论 建立的红曲霉固态发酵工艺合理，为稀有皂苷Rg₃定向化生产奠定了基础，更为日后体外制备稀有人参皂苷提供了理论支持。

Objective To explore the solid fermentation process of Panax ginseng by Monascus purpureus, which can transfer some major ginsenoside into rare ginsenoside Rg₃ with stronger biological activity. Methods The static dark culture method was used to perform microbial fermentation; Vanilline-glacial acetic acid method was used to detect the total saponins before and after fermentation, and the ginsenoside Rg₃ was detected by HPLC. Results The optimum process parameters of Monascus purpureus fermentation was fermentation 6 d, fermentation temperature 32℃, pH 7.0, and water content of substrate 50%. After 6 d of fermentation, the content of total saponins in fermentation products increased by 40%, and the content of ginsenoside Rg₃ was 6.047 mg/g, which was 2.3 times as much as that of non-fermented P. ginseng. According to the change of monomer saponin content along with the fermentation time, it was deduced that the transformation path was Rb₁ (Rb₂)→Rd→Rh₂→Rg₃. Conclusion The solid fermentation process of Monascus purpureus established in this study is reasonable, which not only lays a foundation for the directional production of rare saponins Rg₃ but provides a theoretical support for preparing rare ginsenoside in vitro.

国家高技术研究发展计划（"863"）项目（2013AA102604-3）；吉林省发改委-吉林省省级产业创新专项（2016C064）