175results about How to "Improve feed utilization" patented technology

The invention relates to an acidic proteinase and a preparation method thereof and the acidic proteinase belongs to the microbial acidic proteinase. The invention is characterized in that 1) the enzymatic characteristics of the acidic proteinase are as follows: the optimum pH value is 2.5-3.5, the stable pH value is 2.5-6.0; the optimum temperature is 40-50 DEG C, the temperature stability range is 30-50 DEG C; and 2) the preparation method uses Aspergillus Niger which is stored in the China Center of Industrial Culture Collection (CICC) and has a preservation number of 2238, as the enzyme-producing strain and uses wheat bran as the raw material; the solid fermentation technology is adopted for preparation; the fermentation and enzyme-producing capability is not less than 47000u / g (dry yeast), the liquid enzyme yield is not less than 85% and the soid enzyme yield is not less than 80%, which all achieve the food grade sanitation standard. The invention provides the acidic proteinase and the preparation method thereof, wherein the utilization rate of the fermentation equipment is high, the byproduct of crop processing is used as the main raw material, the enzyme activity for fermentation is high, the extracting and purifying rate of enzyme is high and the production cost is low. The acidic proteinase of the invention is suitable to be used as the raw material or product additive of the products in the leather industry, the pharmaceutical industry, the brewing industry and the feed industry.