Method for preparing leucine aminopeptidase through fermentation of bacillus subtilis engineering bacteria

Abstract

The invention relates to a method for preparing leucine aminopeptidase through the fermentation of bacillus subtilis engineering bacteria, belonging to the technical field of enzymic preparations and food additives. The method is characterized in that the enzyme powder of the leucine aminopeptidase is obtained by using the fermentation production of the bacillus subtilis engineering bacteria and carrying out extraction operations such as flocculation, filtration sterilization, ultrafiltration and concentration, and freeze drying on fermentation liquor, and the basic enzymology characteristics of the prepared leucine aminopeptidase are studied. According to the method, the bacillus subtilis engineering bacteria PMA5-SAP for the high yield of the leucine aminopeptidase, which is structured on the basis of the wild bacillus subtilis engineering bacteria zj016, is further optimized in the fermentation process, the enzyme activity of the leucine aminopeptidase produced in a 7L-fermentation tank is substantially increased by adopting strategies such as the pretreatment of a culture medium, the adjustment of culture medium components, the control of dissolved oxygen level and the like, and the level of enzymes produced through fermentation is increased from 7000U / L (unit for enzyme activity) to about 200000U / L.

Description

technical field [0001] A method for preparing leucine aminopeptidase by fermentation of Bacillus subtilis engineering bacteria, specifically, using Bacillus subtilis engineering bacteria to ferment, collecting fermentation liquid, and performing extraction operations such as flocculation, filtration, ultrafiltration concentration, and freeze-drying to obtain A leucine aminopeptidase product belongs to the technical field of enzyme preparations and food additives. Background technique [0002] Commercial production of proteases began in the early 20th century, and microbial proteases began to be used in the food and leather industry in the 1930s. In recent years, research on microbial enzyme production has flourished. In the early 1950s, Japanese scholars first discovered that there were several types of proteases in molds, especially acid proteases. In the early 1960s, the Netherlands began to produce detergents that added alkaline proteases. So far, there are more than 100...

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Problems solved by technology

[0006] Soy peptide products have different degrees of bitterness, which will directly affect the flavor of food, and it will be "unpleasant" when eaten by people, which also limits its promotion and application in the food industry to a certain extent.

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