Studies Of New Protein Feeds Basing On Acid Protease

The acid protease is a kind of enzyme that is suitable for hydrolysising the protein under the acid condition (pH 1—5).It has already been applied in a lot of industries, such as food, brewing, fur and leather, collagen fiber and fodder, etc.In this study, the possibility and process of using Aspergillus oryzae and yeast in the fodder were investigated. A new technique for producing acid protease feed containing lots of peptides was got. The acid protease of Aspergillus oryzae was purified and some characterization and molecular weight was detected. The result showed it was better for producing the acid protease in Aspergillus oryzae A-29 than Aspergillus oryzae A-79 and the suitable composition of medium was as 51.45% of wheat bran, 7.5% of bean cake powder, 0. 8% of (NH₄)₂SO₄,0.25% of KH₂PO₄ and 40% water. The high enzyme activity of acid protease was tested to incubated at 30°C for 72 hs. The medium of the yeasts was a mixture containing 5% of wheat bran, 9% bean cake powder, 0.8% of (NH₄)₂SO₄ and 11% of hydrolyzed sugar. The fermentation temperature was 30℃. Fermenting 24h, the yeasts in the medium was the most. The process of producing the high-protein biological feed (HPB-1) was adding 7. 5% of Aspergillus oryzae A-29 tanekoji and 9 % of yeast mixture culture(the ratio of CHC-3, DSF-1 and GY-1 was 3∶4∶2) to the SSF medium containing 25% of bean cake powder and 25% of wheat bran and fermented at 30°C for 36hs. The HPB-1 contained the acid protease enzyme(1440U/g), the yeasts (6.29×10⁹/g), protein(0.7056g/g), the aminoacyl(77.7mg/g), the peptides (0.1012g/g) and reducing sugar (0.08g/g).HPB-1 was used to feed pigs. The average daily gain per head of treatment group was 414. 29g/d, it was 88.58g greater than that of control group. The results indicated the pigs growth performance feeding HPB-1 was better than that of feeding the normal protein.The acid protease was elecrophoretic homogeneity by the steps of...