A cleaner production of diosgenin from Dioscorea Zingiberensis Wright biotransformed by Lactobacillus casei

摘要

The effect of 24 probiotics on disogenin production had been conducted in our preliminary work. Consequently, Lactobacillus casei was selected as the fermentation strain with high potential in biotransformation and effects of main parameters on biotransformation were verified through single factor variable experiments. The fermentation conditions were optimized using response surface methodology, which would be helpful to enhance biotransformation efficiency and achieve a high-valued utilization of DZW in diosgenin production. Single factor variable experiments indicated that biotransformation was highly depend on temperature. The conversion rate of saponin reached to (22.1 ± 0.6) %, (15.5 ± 0.3) % and (17.0 ± 0.4) % under each optimal condition of 43°C, 24 hours and 4% inoculum size respectively. According to results of single factor variable experiments, fermentation conditions were optimized through response surface methodology. The 32.4% of conversion rate and 3.95 μg/mL of diosgenin concentration were predicted to be optimal value under the condition of 42°C, 27 hours, 3% inoculum size. The verification results were (32.8 ± 0.9)% of conversion rate and (4.01±0.02) μg/mL of diosgenin concentration under the same conditions, which were close to the predicted values. The conversion rate increased by 41.9% compared to the initial value. Feasibility of converting saponin to diosgenin through probiotics by biotransformation was verified in this paper and the results could be the reference for a cleaner production of diosgenin.