NOVELTY - Converting sisal saponin to sapogenin involves (a) preparing culture medium using peeled potatoes, and adding 100 ml and 200 ml culture medium in Erlenmeyer flasks and 1 l flask, respectively and marking as (I) and (II), (b) adding agar powder in flask (I), inoculating target strain in Petri dish, and incubating to obtain solid culture plate, (c) inoculating flask (II) with colonies grown in solid culture plate, and incubating to obtain liquid culture broth, and (d) extracting sisal hemp, inoculating extract with liquid culture broth, and incubating in shaker.    USE - The method is useful for converting sisal saponin to sapogenin by microbial fermentation (claimed).    ADVANTAGE - The microbial fermentation method for converting sisal saponin to sapogenin is environmentally-friendly, cost-effective and suitable for industrial production of sapogenin, and has rapid and high degradation rate.    DETAILED DESCRIPTION - Converting sisal saponin to sapogenin involves (a) weighing 200-250 g peeled potatoes, chopping peeled potatoes into 1.8-2.2 cm, adding 0.5-1.5 l water, heating for 25-35 minutes, then cooling to room temperature, filtering using three-layer gauze filter, obtaining 0.5-1.5 l culture medium, adding 100 ml culture medium in 250 ml Erlenmeyer flasks and marking as (I), then adding 200 ml culture medium in 1 l flask and marking as (II), (b) adding 1.5 g agar powder in a flask (I), wrapping with a brown paper, sterilizing at 121 degrees C and 1.103 mPa for 20 minutes, immediately adding sterilized medium into a Petri dish having diameter of 9 cm, covering, allowing to stand undisturbed until the agar gets solidified and obtaining a solid culture medium, then inoculating stored target strain in the solid medium, and incubating at 30 degrees C for 72 hours to obtain the solid culture plate, (c) sterilizing flask marked as (II) at 121 degrees C and 1.103 mPa for 20 minutes, cooling to room temperature, inoculating sterilized liquid medium by adding 10 colonies obtained in step (b), incubating in a shaker at 200 rotations per minute and 300 degrees C for 72 hours to obtain liquid culture broth with target strain, and (d) weighing 200 g sisal hemp dry residue, adding 1 l tap water, extracting for 60 minutes, filtering extract using three-layer gauze filter, making filtrate volume to 1 l, sterilizing at 121 degrees C and 1.103 mPa for 20 minutes, transferring to 2 l bottle, aseptically inoculating with 100 ml liquid culture broth obtained in step (c), incubating in a shaker at 200 rotations per minute and 30 degrees C and fermenting for 72 hours to obtain the product containing sapogenin. The target strain selectively isolated from soil sample is deposited as CCTCC M2013322 with a name GLHZB22. The target strain is capable of degrading sisal glycosylated saponin to sapogenin.