RESUMEN
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.
RESUMEN
The relationship between saponin content of in different parts of the organization and expression of ginsenoside biosynthesis related gene was obtained by the correlation analysis between saponin content and gene expression. The 14 tissue parts of were studied, six saponins in Samples (ginsenoside Rg₁, Re, Rb₁, Rc, Rb₂ and Rd), group saponins and total saponins were determined by high performance liquid chromatography and vanillin-sulfuric acid colorimetric method. Simultaneously, the expression levels of 7 ginsenoside biosynthesis related genes ( and ) in different tissues of were determined by Real-time fluorescence quantitative PCR. Although 7 kinds of ginsenoside biosynthesis related enzyme gene in the involved in ginsenoside synthesis, the expression of and P450 genes had no significant effect on the content of monosodium saponins, grouping saponins and total saponins, and had significant or extremely significant on the contents of single saponins Re, Rg1, Rb1, Rd, group saponin PPD and PPT, total saponin TMS and total saponin TS (<0.05 or <0.01). The biosynthesis of partial saponins, grouping saponins and total saponins in was affected by the interaction of multiple enzyme genes in the saponin synthesis pathway, the content of saponins in different tissues of was determined by the differences in the expression of key enzymes in the biosynthetic pathway. Therefore, this study further clarified that and was the key enzyme to control the synthesis of saponins in by correlation analysis, the biosynthesis of ginsenosides in was regulated by these five kind of enzymes in cluster co-expression of interaction mode.