Changes of Nutrient Components during Solid-State Fermentation by Poria cocos Using Wheat as Substrate

Abstract:

Poria cocos was cultured on the solid medium using wheat as the sole substrate. The kinetic changes of extracellular enzyme activities and nutrient components were analyzed. The results showed that the amylase activity reached its maximum（494.2 U/mL） on the 20th day of the fermentation，which was maintained till the fermentation end. The highest xylanase activity of 1 073.2 U/mL appeared on the 20th day，and hereafter a slight decrease was observed. For the cellulase activity，there was an increase with cultivation time，and the maximum activity was up to 1 280.5 U/mL after 40 days cultivation. In comparison with the unfermented wheat，total sugar of fermented-wheat showed significant decrease，whereas the contents of reducing sugar，polysaccharide and triterpenoid were increased obviously. Hence，enzymatic catalysis of Poria cocos by solid-state fermentation could efficiently improve the nutrient value of wheat.