SUMMARY
Background: Ginsenoside is the most important secondary metabolite in ginseng. Natural sources of wild ginseng
have been overexploited. Although root culture can reduce the length of the growth cycle of ginseng, the number
of species of ginsenosides is reduced and their contents are lower in the adventitious roots of ginseng than in the
roots of ginseng cultivated in the field.
Results: In this study, 147 strains of ß-glucosidase-producing microorganisms were isolated from soil. Of these,
strain K35 showed excellent activity for converting major ginsenosides into rare ginsenosides, and a NCBI
BLAST of its 16S rDNA gene sequence showed that it was most closely related to Penicillium sp. (HQ608083.1).
Strain K35 was used to ferment the adventitious root extract, and the fermentation products were analyzed by
high-performance liquid chromatography. The results showed that the content of the rare ginsenoside CK was
0.253 mg mL-1 under the optimal converting conditions of 9 d of fermentation at pH 7.0 in LL medium, which
was significantly higher than that in the adventitious roots of ginseng.
Conclusion: These findings may not only solve the problem of low productivity of metabolite in ginseng root
culture but may also result in the development of a new valuable method of manufacturing ginsenoside CK.