Biotransformation of Ginsenosides by Eoyukjang-derived Lactic Acid Bacteria in Mountain-cultivated Ginseng

Biotransformation of ginsenosides by microorganisms alters the absorption and bioavailability of ginseng as a medicinal herb. In this study, we isolated two kinds of fermenting microorganisms from Eoyukjang, which is a traditional Korean fermented food made from soybean. Next, we identified and detected their ability to convert major ginsenosides to compound K. The two microorganisms, referred to as R2-6 and R2-15, had 100% similarity with Lactobacillus plantarum subsp. plantarum ATCC $14917^T$ and Lactobacillus rhamnosus JCM $1136^T$, respectively. The optimal pH and growth temperature of the isolates were determined to be pH 6-7 and $30^{\circ}C$. After fermentation for 30 days, the major ginsenosides in the mountain-cultivated ginseng were transformed to the highly bioactive ginsenoside, compound K, in the final product.