Biotransformation of ginsenoside Rbl for ginsenoside Rd preparation by Lysinibacillus massiliensis No. 24

Bacterium Lysinibacillus massiliensis No. 24 was tested for its ability to transform the major ginsenosides Rbl. The transformation product was identified by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC), and its structure was assigned by C-13-NMR. The bacterium was found to specifically transform major ginsenoside Rbl and ginsenoside Rd was the sole product. The optimal conditions for transforming Rbl by L. massiliensis No. 24 were determined to be: substrate concentration, 3 mg/mL; temperature, 34 degrees C; pH 10; the time of substrate addition, 48 h; cell concentration, 0.30x10(9) cells/mL; and biotransformation period, 3 d. Under the optimum conditions, the maximum yield of ginsenoside Rd reached 97%. Further, a preparative scale transformation with L. massiliensis No. 24 was performed with 150 mg Rbl to give a yield of 79%. This bacterium would be potentially applied in the preparation of Rd.