Key Laboratory of Natural Resources of Changbai Mountain and Functional Molecules, Ministry of Education, Yan Bian University, Gongyuan Road, Yanji 133002, Jilin, China.
J Ind Microbiol Biotechnol. 2012 Apr;39(4):521-7. doi: 10.1007/s10295-011-1058-9. Epub 2012 Jan 20.
Rb₁ and Rg₁ are the major ginsenosides in protopanaxadiol and protopanaxatriol. Their content in ginsenosides was 23.8 and 17.6%, respectively. A total of 22 isolates of β-glucosidase producing microorganisms were isolated from the soil of a ginseng field using Esculin-R2A agar. Among these isolates, the strain GH21 showed the strongest activities to convert ginsenoside Rb₁ and Rg₁ to minor ginsenosides compound-K and F₁, respectively. Ginsenosides Rb₁ and Rg₁ bioconversion rates were 74.2 and 89.3%, respectively. Meanwhile, the results demonstrated that the ginsenoside Rg₁ could change the biotransformation pathway of ginsenoside Rb₁ by inhibiting the formation of the intermediate metabolite gypenoside-XVII. GH21 was identified as a Cladosporium cladosporioides species based on the internal transcribed spacers (ITS) ITS1-5.8S-ITS2 rRNA gene sequences constructed phylogenetic trees.
Rb₁和 Rg₁是原二醇和原三醇型人参皂苷中的主要成分，其含量分别为 23.8%和 17.6%。从人参地土壤中用 Esculin-R2A 琼脂分离到 22 株产β-葡萄糖苷酶的微生物分离株。在这些分离株中，菌株 GH21 对转化人参皂苷 Rb₁和 Rg₁分别生成次要人参皂苷化合物-K 和 F₁的活性最强。人参皂苷 Rb₁和 Rg₁的转化率分别为 74.2%和 89.3%。同时，结果表明，人参皂苷 Rg₁通过抑制中间体代谢物人参皂苷 XVII 的形成改变了人参皂苷 Rb₁的生物转化途径。GH21 根据内部转录间隔区（ITS）ITS1-5.8S-ITS2 rRNA 基因序列构建的系统发育树被鉴定为棒曲霉（Cladosporium cladosporioides）种。
