The Application Of New Enzymes In Ethanol Fermentation

This thesis is to study the effects on enzyme application on high gravity alcohol fermentation. Using Genencor's technology and enzymes for example acid protease GC106 and analysis samples with HPLC we can do deep study on ethanol fermentation. With the acid protease the fermentation time can be shortened 8 hours, and the ethanol yield based on starch could be improved to 17.7% compare with the blank. This study also compared the contents of protein in DDGS from processes with and without acid protease;the data indicated that using the acid protease could improve the quantity of DDGS. This study also studied the optimal conditions of the high gravity fermentation. In addition, use of cellulase and xylanase in tapioca ethanol fermentation were also investigated, and it was found that the fermentation time could be shorten and the ethanol yield be increased.