title: Evaluation of different pretreatments on microbial transformation of saponins inDioscorea zingiberensisfor diosgenin production.
abstract: In order to evaluate the effects of different pretreatments on microbial transformation of saponins inDioscorea zingiberensis(DZW), various methods have been systematically studied on a large scale. Five pretreatments, including physical separation, catalytic solvent extraction, ultrasonic fermentation, complex enzymatic hydrolyzation and enzymatic saccharification, were performed on DZW. Compared with other methods, complex enzymatic hydrolyzation significantly improved the efficiency of microbial transformation. Due to the pretreatment, a diosgenin yield of 92.6%, and diosgenin accumulation of 27.3 mg/g DZW were achieved. The high efficiency of this method was attributed to the separation of 84.3% starch and 76.5% fibre from DZW in the form of a sugar. Analysis of saponins in this microbial transformation process showed that the residual rates of the intermediate products were much lower than those obtained from other pretreatments. The results demonstrate that complex enzymatic hydrolyzation is a practical and effective pretreatment method for production of diosgenin from DZW in a microbial transformation way.
authors.affiliation: College of Life Science, Shaoxing University , Shaoxing , China.
authors.forename: Tianxiang
authors.initials: T
authors.lastname: Zheng
authors.affiliation: College of Life Science, Shaoxing University , Shaoxing , China.
authors.forename: Lidan
authors.initials: L
authors.lastname: Yu
authors.affiliation: College of Life Science, Shaoxing University , Shaoxing , China.
authors.forename: Yuling
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: The State Key Laboratory of Hollow Fibre Membrane Materials and Processes, Tianjin Polytechnic University , Tianjin , China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhao
keywords: diosgenin; microbial transformation; pretreatment; saponins