• Microbiology and Biotechnology Letters
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• v.14 no.5
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• pp.391-397
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• 1986

Three kinds of microoganisms were isolated and identified from the ginseng and ginseng products to research the properties of the molds which spoil the ginseng and ginseng products. The results obtained were as follows: (1) The predominant strains on ginseng products were Aspergillus sp., Penicillium sp.-A and Penicillium sp.-B. These predominant fungi deteriorated ginseng products exclusively, (2) Aspergillus sp. showed the greatest mycelial growth at $40^{\circ}C$ and its optimum pH was 5, meanwhile Pencillium sp. showed the greatest mycelial growth at $30^{\circ}C$ and its optimum pH was 3. (3) The growth of the isolated strains was stimulated with the increase in the concentration of saponin at the lower concentration, meanwhile it was inhibited at 1.0% concentration of saponin.

• Microbiology and Biotechnology Letters
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• v.10 no.1
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• pp.1-7
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• 1982

A Rhizopus sp. was selected for its strong cellulolytic activity among various strains of molds found in rotting ginseng roots. Studies were made on some properties of the cellyloiytic enzyme produced by the strain. The results obtained were summarized as follows: The optimum pH of the enzyme was 4.5 and the range of its stability to the pH was 3.0 to 7.0. The optimum temperature was 5$0^{\circ}C$, while the enzyme was instantly inactivated above 6$0^{\circ}C$. Mn$^{＋＋}$ and Co$^{＋＋}$ ions increased enzyme activity and the metal ions were found to increased the ther-mostability of the enzyme. This enzyme was inhibited by sodium dodecyl sulfate and 2,4-dinitrophenol. This enzyme had a strong cellulolytic enzyme activity on various native cellulose given a sufficient reaction time. The addition of 0.5% saponin solution into reaction mixture increased the enzyme activity.

• Microbiology and Biotechnology Letters
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• v.10 no.4
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• pp.267-273
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• 1982

Among 12 kinds of ginsenosides in ginseng saponin, ginsenoside-Rb$_1$was contained the most abundantly. But ginsenoside-Rd which is similar to ginsenoside-Rb$_1$in structure, was known to be superior to ginsenoside-Rb$_1$pharmaceutically. In order to convert ginsenoside-Rb$_1$into ginsenoside-Rd by microbial enzyme treatment, a Rhizopus sp. was selected among various strais of molds found in rotten ginseng roots. Enzyme was prepared from the extract of wheat bran koji culture by ammonium sulfate precipitation (1.0 sat'd) and succeeding ammonium sulfate fractionation method (0.6-0.9 sat'd). For the purpose of use as substrate, saponins were purified by the several purification steps from alcohol extract of red ginseng roots. We obtained the total saponin which was composed of 36.5% of ginsenoside Rb$_1$, 12.2% of ginsenoside-Rd and other ginsenosides. For increase of ginsenoside-Rb$_1$ component ratio, we also obtained further purified ginsenoside-Rb group saponin containing 54.5% of ginsenoside-Rb$_1$, 1.1% of ginsenoside- Rd and other ginsenosides from purified the total saponin. In the enzymatic reaction system including the total saponin or the ginsenoside-Rb group saponin, we confirmed the specific conversion of ginsenoside-Rb$_1$to ginsenoside-Rd proportionally and no change of any other ginsenoside patterns by thin layer chromatography and high performance liquid chromatography.