产ACE抑制肽乳酸菌的筛选、益生特性评定及应用

宋小玲; 高冀婷; 曹菲薇; 胡子毅; 任大喜

doi:10.13386/j.issn1002-0306.2021080212

产ACE抑制肽乳酸菌的筛选、益生特性评定及应用

Screening, Probiotic Properties Evaluation and Application of ACE-inhibitory Peptide-producing Lactic Acid Bacteria

摘要

摘要: 目的：筛选出富产血管紧张素转化酶（Angiotensin converting enzyme，ACE）抑制肽的乳酸菌并评定其益生特性。方法：依据蛋白水解度及ACE抑制率对乳酸菌进行初筛，然后依据模拟胃肠消化后的ACE抑制率最终筛出2株乳酸菌ZJUIDS09和ZJUIDS11，进一步评价其耐酸、耐胆盐、抗生素耐药性和抑菌活性等益生特性，最后评定两株菌对荷斯坦脱脂乳、荷斯坦乳清、水牛脱脂乳和水牛乳清发酵后产物ACE抑制率。结果：筛选出菌株ZJUIDS09和ZJUIDS11，其发酵乳的蛋白水解度分别为5.79%±0.14%和5.75%±0.10%，ACE抑制率分别为87.39%±2.44%和90.41%±0.99%，IC₅₀值分别为0.31和0.25 mg/mL，经人工胃肠液消化后ACE抑制率分别为70.13%±0.15%和76.39%±2.91%。菌株ZJUIDS09和ZJUIDS11都具有良好的耐酸耐胆盐、抗菌和抗生素敏感性，经16S rDNA鉴定分别为罗伊氏乳杆菌（Lactobacillus reuteri）和瑞士乳杆菌（Lactobacillus helveticus）。通过对比同一蛋白浓度下不同底物（荷斯坦脱脂乳、荷斯坦乳清、水牛脱脂乳和水牛乳清）经菌株发酵后的ACE抑制率，确定菌株ZJUIDS09和ZJUIDS11的最佳发酵底物为荷斯坦脱脂乳。结论：本研究筛选的罗伊氏乳杆菌ZJUIDS09和瑞士乳杆菌ZJUIDS11有较强的产ACE抑制肽能力，具有开发降血压功能发酵乳制品的潜力。

Abstract: Objectives: To screen lactic acid bacteria (LAB) produced angiotensin-converting enzyme (ACE) inhibitory peptides and to evaluate their probiotic properties. Methods: Lactic acid bacteria were inoculated into skimmed milk, the proteolysis degree and ACE inhibition rate of fermented milk were determined by colorimetric assays. Two LAB (ZJUIDS09 and ZJUIDS11) that resulted in the highest proteolysis degree and ACE inhibition rate were selected, and their probiotic properties were evaluated, including acid resistance, bile salt resistance, antibiotic resistance, and antibacterial activity. The fermented milk produced by the two strains was treated with simulated gastrointestinal digestive juices, and their ACE inhibition rates were determined. Finally, the two strains were used as starter cultures in the fermentation of Holstein skim milk, Holstein whey, buffalo skim milk and buffalo whey, and the ACE inhibition rates of the fermented milk were determined. Results: The degrees of proteolysis of fermented milk produced by strain ZJUIDS09 and ZJUIDS11 were 5.79%±0.14% and 5.75%±0.10%, respectively. Their ACE inhibition rates were 87.39%±2.44% and 90.41%±0.99%, respectively. And their IC₅₀ were 0.31 and 0.25 mg/mL, respectively. Their ACE inhibition rates after digestion with simulated gastrointestinal juices were decreased to 70.13%±0.15% and 76.39%±2.91%, respectively. Strains ZJUIDS09 and ZJUIDS11 were resistant to acid and bile salt, exhibited antibacterial activity and antibiotic sensitivity, and were identified as Lactobacillus reuteri and Lactobacillus helveticus by 16S rDNA. Comparing Holstein skim milk, Holstein whey, Buffalo skim milk and Buffalo whey after strain fermentation, Holstein skim milk was the most suitable substrates for strains ZJUIDS09 and ZJUIDS11 to produce ACE-inhibitory peptides. Conclusion: Lactobacillus reuteri ZJUIDS09 and Lactobacillus helveticus ZJUIDS11 screened in this study had a strong ability to produce ACE inhibitory peptides and had the potential to develop fermented dairy products with blood pressure-lowering effect.