Microbial transformation of ginsenosides extracted from Panax ginseng adventitious roots in an airlift bioreactor

Abstract

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 species number of ginsenosides is reduced and their contents are lower in adventitious roots of ginseng than in ginseng cultivated in the field. Results: In this study, 147 strains of β-glucosidase-producing microorganisms were isolated from soil. Of these isolates, strain K35 showed excellent activity in 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 HPLC. 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. Normal 0 false false false EN-US ZH-CN X-NONE st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:Tabla normal; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.5pt; mso-bidi-font-size:11.0pt; font-family:Calibri,sans-serif; mso-bidi-font-family:Times New Roman; mso-font-kerning:1.0pt; mso-fareast-language:ZH-CN;}