A kind of purification method of food grade neutral protease

Abstract

The invention discloses a purification method for food-grade neutral protease. The purification method comprises the following steps: (1) fermenting a bacillus subtilis AS1.398 strain to obtain a neutral protease fermented solution, and adding a flocculating agent into the fermented solution; (2) carrying out plate frame filtering, namely carrying out plate frame filtering on the neutral protease fermented solution, and collecting a filtering solution; (3) centrifuging, namely carrying out high-speed centrifuging on the filtering solution collected by the plate frame filtering step; (4) coarsely filtering, namely coarsely filtering the collected centrifuging solution; (5) finely filtering, namely filtering by a polysulfone ultra-filtration membrane, and concentrating; (6) adding an enzyme activity protection agent, namely adding mycose and beta-cyclodextrine; (7) precipitating, namely adding edible ethanol and collecting a precipitated part of neutral protease; and (8) drying in vacuum to obtain the food-grade neutral protease. According to the purification method for the food-grade neutral protease, the problem that the activity of the neutral protease is lost can be solved effectively and the enzyme activity yield is improved obviously; the total extracting yield of the food-grade neutral protease is up to more than 70% and hygienic indexes meet food-grade requirements; the purification method for the food-grade neutral protease can be applied to a food processing industry.

Description

technical field [0001] The invention relates to the field of biotechnology, in particular to a method for purifying food-grade neutral protease. Background technique [0002] At present, the industry has used Bacillus subtilis AS1.398 to produce neutral protease for many years. It is a kind of enzyme widely used in industrial production. Has a wide range of uses. At present, the production process of neutral protease by fermentation in my country is mainly to spray dry the fermentation liquid directly or dry it after salting out and precipitating. Due to the limitation of the production process, the enzyme activity of this kind of product is greatly lost in the high temperature environment, and the yield of the enzyme activity is low. There are many impurities in the product, and the hygienic indicators such as microorganisms do not meet the requirements of the food industry, and the scope of application is limited. Therefore, it is necessary to separate and purify the neutr...

AI Technical Summary

Problems solved by technology

At present, the production process of neutral protease by fermentation in my country is mainly to spray dry the fermentation liquid directly or dry it after salting out and precipitating. Due to the limitation of the production process, the enzyme activity of this kind of product is greatly lost in the high temperature environment, and the yield of the enzyme activity is low. There are many impurities in the product, and the hygienic indicators such as microorganisms do not meet the requirements of the food industry, and the scope of application is limited. Therefore, it is necessary to separate and purify the neutral protease in the fermentation broth

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