| 摘要 |
PURPOSE:A protease which has been produced by a microorganism in a specific genus is added to the formulated feed to give a feed for piglings which is suitable for feeding piglings with high digestibility. CONSTITUTION:Wheat bran is combined with water to adjust its water content to 45-55%, steamed under pressure at 120 deg.C for 30min, cooled down and inoculated with a preculture solution in an amount of 10-20%, which has been prepared by culturing a microorganism producing the protease in Rhizopus in a liquid medium containing 10% of wheat bran at 25-30 deg.C for about 20hr. The resulting mixture is cultured at 25-30 deg.C for 3-4 days, the culture mixture is extracted with water in an amount of 5 times the mixture, then ethanol is added under cooling and stirring so that the concentration reaches 50-70% and stood at 10-20 deg.C. The precipitate is washed twice with ethanol, collected by centrifugation and dried under vacuum at about 40 deg.C. The resultant protease is acid-resistant and is not decomposed by the gastric acid in piglings. |
