Application of magnetically immobilized edible fungus for the biotransformation of panax notoginseng saponin Rb1 to Rd and Rg3

•Immobilized edible fungus was used for Panax notoginseng biotransformation.•Magnetically immobilized fungus showed higher efficiency than the non-magnetical.•Magnetically immobilized biocatalyst could be reused at least 15 runs.

In this study, we developed a new magnetically immobilized edible fungus for the biotransformation of panax notoginseng saponins Rb1 to Rd and Rg3. The optimum biotransformation conditions were as follows: temperature 32 °C, pH 6.5, time 48 h and liquid-solid ratio 25:1 (mL/g). The yields of Rd and Rg3 reached 41.35 ± 0.12 mg/g and 6.35 ± 0.08 mg/g which increased 6.97-fold and 3.23-fold to that of untreated control, respectively. Additionally, SEM demonstrated that vestured pits and cell walls of samples were destroyed obviously which was beneficial to the Rb1 biotransformation and target Rd and Rg3 release. Meanwhile, the reusability of magnetically immobilized microorganism was tested and the activity of the magnetically immobilized microorganism remained 83.8% after 15 runs. The recycling experiments demonstrated that magnetically immobilized fungus exhibited higher efficiency than the non-magnetical one. These results proved that this new magnetically immobilized microorganism could be applied for industrial production and pharmaceutical industry with good efficiency.

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