Université Lille, INRA, ISA, Université d'Artois, Université Littoral Côte d'Opale, EA 7394-ICV Institut Charles Viollette, F-59000 Lille, France; VF Bioscience, Parc Eurasanté, F-59120 Loos-lez-Lille, France.
Université Lille, INRA, ISA, Université d'Artois, Université Littoral Côte d'Opale, EA 7394-ICV Institut Charles Viollette, F-59000 Lille, France.
Food Chem. 2020 Jan 30;304:125415. doi: 10.1016/j.foodchem.2019.125415. Epub 2019 Aug 22.
The aim of our study was to characterize the proteolytic activity of 170 Lactobacillus strains isolated from traditional Mongolian dairy products (yogurt and fermented milk), and to investigate their capacity to generate bioactive peptides during milk fermentation. All isolates were screened for proteolytic activity using skim milk agar-well diffusion test. Fifteen strains (9 Lactobacillus helveticus and 6 Lactobacillus delbrueckii subsp. bulgaricus) were then selected and further evaluated using an original strategy based on multiparametric analysis, taking into account growth rate, acidification capacity, proteolytic activity, cell envelope associated peptidase (CEP) profile and LC-MS/MS analysis of peptides. All parameters were analyzed using principal component analysis (PCA). Results showed that strain growth and acidification correlate with peptide production and that Mongolian L. helveticus strains differ from Western strains in terms of CEP distribution. The PCA revealed that CEP profiles are major determinants of β-casein hydrolysis patterns. Strains with distinctive proteolytic activities were identified.
本研究旨在分析从传统蒙古乳制品（酸奶和发酵乳）中分离出的 170 株乳杆菌的蛋白水解活性，并研究其在牛奶发酵过程中生成生物活性肽的能力。采用脱脂乳琼脂打孔扩散试验对所有分离株进行蛋白水解活性筛选。随后选择 15 株（9 株瑞士乳杆菌和 6 株德氏乳杆菌保加利亚亚种），并采用一种基于多参数分析的原始策略进行进一步评估，综合考虑生长速度、酸化能力、蛋白水解活性、细胞周质相关肽酶（CEP）图谱和肽的 LC-MS/MS 分析。使用主成分分析（PCA）对所有参数进行分析。结果表明，菌株的生长和酸化与肽的产生相关，而且蒙古乳杆菌菌株在 CEP 分布方面与西方菌株不同。PCA 表明，CEP 图谱是 β-酪蛋白水解模式的主要决定因素。鉴定出具有独特蛋白水解活性的菌株。
