Method for preparing liquid-state chymosin preparation

Abstract

The invention discloses a method for preparing a liquid-state chymosin preparation. The method comprises the following steps: (1) preparing fermentation liquor by taking bacillus amyloliquefaciens CCTCC NO:M2011045 or bacillus subtilis CCTCC NO:M2010259 as a fermentation strain; (2) performing plate-frame pressure filtration, and performing solid-liquid separation; (3) performing montmorillonite adsorption; (4) performing microfiltration; (5) performing ultrafiltration and concentration; and (6) adding cane sugar or trehalose with the final concentration of 20-40 weight percent, glycerol or sorbitol with the final concentration of 0-30 weight percent and calcium chloride with the final concentration of 0.01-0.05 weight percent into a concentrated enzyme solution, uniformly mixing, and preparing the finished product. According to the method, the chymosin is high in activity and recovery rate, protease, other impurities and residual bacteria in the enzyme solution can be effectively removed, and the prepared enzyme preparation has high quality and stability and is high in enzyme specifity, long in retention period, safe and non-toxic.

Description

technical field [0001] The invention belongs to the technical field of biological fermentation engineering and enzyme preparations, and in particular relates to a method for extracting and preparing a liquid rennet preparation from fermentation liquid of Bacillus amyloliquefaciens or Bacillus subtilis. Background technique [0002] Rennet is a key enzyme in cheese production. It coagulates raw milk in two stages: α-casein and β-casein in casein micelles will not coagulate spontaneously under the action of κ-casein , first, chymosin decomposes κ-casein specifically into p-κ-casein and a macropeptide, destabilizing casein micelles; then, in Ca 2+ Under the action, p-κ-casein, α-casein and β-casein form chemical bonds to produce precipitation. [0003] The traditional method for preparing rennet is to extract it from the fourth stomach (abomasum) of a calf. However, with the continuous expansion of the cheese industry, the production of rennet by slaughtering young animals can...

AI Technical Summary

Problems solved by technology

[0005] However, the existing liquid type chymosin extraction and preparation process still has the following disadvantages: the recovery rate of chymosin activity is not high, and the activity of the prepared enzyme preparation is on the low side; fermentation often produces other protease impurities with higher activity. During product storage, the presence of these proteases will not only lead to the degradation of chymosin, making it difficult for liquid dosage forms to maintain high rennet activity at room temperature for a long time, the half-life of the enzyme activity is short, and the stability is poor. It will also cause defects such as weak specificity of rennet, rapid hydrolysis and coagulation, excessive protein hydrolysis, increase of soluble small molecular substances, and generation of bitter substances, thereby reducing the yield of cheese and seriously affecting the taste and quality of cheese. limits the application of liquid rennet