Application of Flavobacterium flavum in conversion of panax notoginseng saponins into small-polarity ginsenoside

The invention discloses application of Flavobacterium flavum in conversion of panax notoginseng saponins into small-polarity ginsenoside. The Flavobacterium flavum strain is separated from fresh panax notoginseng root soil, has the activity of converting five saponin monomer mixtures in panax notoginseng saponins into small-polarity ginsenoside, and the conversion products are rich and include 10 rare small-polarity ginsenoside; the Flavobacterium flavum fermentation process is simple, room-temperature continuous oxygen-introducing culture is needed, and the industrial application prospect is wide; and compared with the chemical structure of the substrate and the product, the Flavobacterium flavum enzyme system has three activities of hydrolyzing protopanoxadiol and glucosyl on the C-20 site of triol-type saponin, generating a 20(R/S) -ginsenoside stereoisomer, oxidizing the C-20 site hydroxyl to generate (20, 21) type and (20, 22) type double bonds, and the characteristic is also found for the first time in