Rapid screening method for Lactobacillus helveticus rich in ace-inhibiting active peptides, combined sequence and construction method for realizing the method

Abstract

The invention provides application of a union sequence, containing Lactobacillus helveticus genomes pepX and pepN and a gene pepO, in screening high-yielding ACE (angiotensin converting enzyme) bioactive peptide restraining Lactobacillus helveticus. The invention further provides a rapid screening method for the high-yielding ACE bioactive peptide restraining Lactobacillus helveticus. The rapid screening method includes: (1) extracting genome DNA (deoxyribonucleic acid) of Lactobacillus helveticus bacterial strains; (2) constructing union gene sequences of the to-be-screened bacterial strains; comparing the union gene sequences of the to-be-screened bacterial strains with a union gene nucleotide sequence as shown in the SEQ No.1, constructing a phylogenetic tree through a neighbor-joining method, and acquiring classifications of the Lactobacillus helveticus through the phylogenetic tree; (4) identifying the bacterial strains, shown in the same branch of Lactobacillus helveticus H9, in the phylogenetic tree as the high-yielding ACE bioactive peptide restraining Lactobacillus helveticus. The rapid screening method is capable of screening the high-yielding ACE bioactive peptide restraining Lactobacillus helveticus effectively and has the advantages of low screening cost and simplicity in operation.

Description

【Technical field】

[0001] The invention relates to the field of genetic engineering, in particular to a method for rapidly screening Lactobacillus helveticus rich in ACE-inhibiting active peptides, and a combination sequence for realizing the method. 【Background technique】

[0002] Lactobacillus helveticus (Lactobacillus helveticus) is a recognized probiotic lactic acid bacteria, widely used in fermented milk, cheese and other dairy industries. According to literature reports, Lactobacillus helveticus has a strong proteolytic enzyme system, and the fermented milk produced by it can metabolize a large amount of biologically active tripeptides VPP and IPP, which has the effect of lowering blood pressure. Whether fermented milk products have the effect of lowering blood pressure and the strength of the function of lowering blood pressure are closely related to the type of starter used and the content and type of antihypertensive peptides in fermented milk. VPP and IPP are the mo...

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