Serratia sp. and application thereof in protease production

Abstract

The invention discloses Serratia sp. and application thereof in protease production, and belongs to the technical field of microorganisms and the technical field of fermentation. The invention provides the Serratia sp. JWG-D15. The Serratia sp. JWG-D15 can produce protease with an amino acid sequence shown as SEQ ID NO.1 and with high yield. The Serratia sp. JWG-D15 is subjected to shake flask fermentation for 2 days under the induction of rice protein, so that the protease activity in the fermentation supernatant can reach 400-460 U / mL. The protease which is obtained by fermentation of the Serratia sp. JWG-D15 and has an addition amount of final enzyme activity of 500 U / mL is added into rice protein dispersion with rice protein concentration of 10 g / L for reaction, and the content of riceoligopeptide in reacted supernatant can reach 62.5% and the content of free amino acid can be reduced to 9.4% only by reaction for 2 hours.

Description

technical field [0001] The invention relates to a Serratia bacterium and its application in the production of protease, belonging to the technical field of microorganisms and the field of fermentation technology. Background technique [0002] Rice protein is recognized as a high-quality protein. Compared with soybean protein, whey protein and other proteins, it has less nutritional inhibitory factors, no allergic reactions, contains amino acids required by the human body, and has a reasonable ratio of amino acids, and its biological value far exceeds soybean protein. , comparable to the biological value of shrimp and beef, and in line with the ideal model recommended by the World Health Organization (WHO). After the rice protein is hydrolyzed into short peptides, it can also be made into a short peptide nutrient solution with higher nutritional value, which is used as a high-value additive in health care products, beverages, cosmetics and other industries. [0003] Among ri...

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Problems solved by technology

However, the enzymatic hydrolysis method has many defects. For example, the preparation method described in the patent publication No. CN1102229643A can make the oligopeptide content in the obtained rice peptide product as high as about 50%, but it needs to use a variety of enzyme preparations in the preparation process Synergistic enzymatic hydrolysis, and it requires the use of hollow fiber membranes, which greatly prolongs the production cycle of rice peptide products and increases the industrial production cost of rice peptide products; the preparation method described in the patent with publication number CN106967773A can also make the obtained The oligopeptide content in rice peptide products is as high as about 50%, but the enzymes used in the preparation process are leucine and proline aminopeptidase, both of which are endoproteases , cutting the end of the polypeptide, so that the free amino acid content in the rice peptide product prepared by this method is as high as about 35%, which greatly affects the quality of the rice peptide product; the patent with the publication number CN103440949A first adopts crushing, pulping, and washing , pulping, reaction, concentration, dehydration and other steps to pretreat the rice dregs, and then use a variety of proteases to synergistically treat the pretreated rice dregs. However, this method mainly improves the content of rice peptide products by pretreatment. Oligopeptide content, before and after the enzymatic hydrolysis process, the oligopeptide content in the rice peptide product does not change significantly, and the preparation steps of this method are cumbersome, energy consumption is large, and the amount of enzyme added is large, which is not conducive to the process of industrialization

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