Study On The Production And Application Of The Feed Enzyme-complex By Aspergullus Niger With Solid-state Fermentation Of Spent Grains

The effects of the medium ingredients and cultivation conditions to the activity of cellulose enzyme,acid protease and xylanase produced by Aspergillus niger strain h-1 were carried out. The enzyme properties of cellulose enzyme,acid protease and xylanase were also studied. And preliminary studies of the feed enzyme-complex in use of three common diet types were carried out.Flask solid-state fermentation experiments were carried out. The results showed that the medium ingredients and the cultivation conditions affected the rate of cellulose enzyme,acid protease and xylanase. In the optimal condition, the activity of cellulose enzyme,acid protease and xylanase were 18.0U/g,3800U/g,1200U/g respectively.Extraction of the crude enzyme preparation by 60% ethanol precipitation,the activity of cellulose enzyme,acid protease and xylanase were85.0U/g,24000U/g,8156U/g respectively.The results of enzyme property researches showed that the loss of feed enzyme-complex activity was less than 20% at pH5.5-7.0,40℃for 6h. But it was more than that at pH2.4-4.0. Because pH of ruminants digestive were at 5.5-7.0,the feed enzyme-complex was suitable to feed of ruminants.Taking the reducing sugar amount and TCA-NSI for indicators, the feed enzyme-complex in application of three common diet types was carried out. Adding feed enzyme-complex 0.1% to maize-soybean meal diet, the reducing sugar amount and TCA-NSI were 4.8% and 23% respectively. Adding feed enzyme-complex 0.1% to wheat-based diet, the reducing sugar amount and TCA-NSI were 4.0% and 18.0% respectively. Adding feed enzyme-complex 0.1% to cotton seed meal, the reducing sugar amount and TCA-NSI were 1.8% and 20% respectively.