The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing, China.
Bioprocess Biosyst Eng. 2010 Jun;33(5):647-55. doi: 10.1007/s00449-009-0390-1. Epub 2009 Nov 15.
Based on the response surface methodology, an effective microbial system for diosgenin production from enzymatic pretreated Dioscorea zingiberensis tubers with Trichoderma reesei was studied. The fermentation medium was optimized with central composite design (3(5)) depended on Plackett-Burmann design which identified significant impacts of peptone, K(2)HPO(4) and Tween 80 on diosgenin yield. The effects of different fermentation conditions on diosgenin production were also studied. Four parameters, i.e. incubation period, temperature, initial pH and substrate concentration were optimized using 4(5) central composite design. The highest diosgenin yield of 90.57% was achieved with 2.67% (w/v) of peptone, 0.29% (w/v) of K(2)HPO(4), 0.73% (w/v) of Tween 80 and 9.77% (w/v) of substrate, under the condition of pH 5.8, temperature 30 degrees C. The idealized incubation time was 6.5 days. After optimization, the product yield increased by 33.70% as compared to 67.74 +/- 1.54% of diosgenin yield in not optimized condition. Scale-up fermentation was carried out in a 5.0 l bioreactor, maximum diosgenin yield of 90.17 +/- 3.12% was obtained at an aeration of 0.80 vvm and an agitation rate of 300 rpm. The proposed microbial system is clean and effective for diosgenin production and thus more environmentally acceptable than the traditional acid hydrolysis.
基于响应面法，研究了用里氏木霉对酶预处理的盾叶薯蓣块茎进行薯蓣皂苷元生产的有效微生物体系。根据 Plackett-Burmann 设计，利用中心复合设计（3(5)）优化了发酵培养基，确定了蛋白胨、K(2)HPO(4)和吐温 80 对薯蓣皂苷元产量的显著影响。还研究了不同发酵条件对薯蓣皂苷元生产的影响。通过 4(5)中心复合设计优化了四个参数，即培养期、温度、初始 pH 值和底物浓度。在 2.67%（w/v）蛋白胨、0.29%（w/v）K(2)HPO(4)、0.73%（w/v）吐温 80 和 9.77%（w/v）底物的条件下，获得了 90.57%的最高薯蓣皂苷元产量，pH 值为 5.8，温度为 30 摄氏度。理想的培养时间为 6.5 天。优化后，与未优化条件下 67.74 +/- 1.54%的薯蓣皂苷元产量相比，产物产量提高了 33.70%。在 5.0 l 生物反应器中进行放大发酵，在通气量为 0.80 vvm 和搅拌速度为 300 rpm 的条件下，获得了 90.17 +/- 3.12%的最大薯蓣皂苷元产量。该微生物体系清洁高效，用于薯蓣皂苷元生产，比传统的酸水解更具环境可接受性。
