Modification of cellulase and its application to extraction of diosgenin from Dioscorea zingiberensis C.H. Wright

In order to enhance the thermostability and efficiency of cellulase in the extraction of diosgenin from Dioscorea zingiberensis C.H. Wright, we applied polyethylene glycol (PEG) (400, 1000, 2000, and 4000) to modify cellulase. The modified cellulase, α-amylase and β-glycosidase were used to hydrolyze the material. The results show that the thermostability of modified cellulase is better than that of natural cellulase, the optimum pH value and temperature of modified cellulase are wider than that of natural cellulase, the activity of cellulase modified by activated PEG2000 is higher than that of cellulase modified by other modifiers, and its remaining activity is 58% of its initial value. With this technique, the purity of the product reaches 96%, the melting point is 201–204 °C, the yield rate and the extraction rate of the diosgenin reaches 2.80% and 96.6%, respectively. IR spectra and 1H NMR spectroscopy were used to confirm the structure of the product.