Department of Microbiology and Biotechnology, Max Rubner-Institut (Federal Research Institute of Nutrition and Food), Hermann-Weigmann-Str. 1, D-24103, Kiel, Germany.
Department of Safety and Quality of Milk and Fish, Max Rubner-Institut (Federal Research Institute of Nutrition and Food), Kiel, Germany.
Appl Microbiol Biotechnol. 2017 Oct;101(20):7621-7633. doi: 10.1007/s00253-017-8369-3. Epub 2017 Jul 10.
In a screening for proteolytically active lactic acid bacteria, three strains, Lactobacillus delbrueckii ssp. lactis 92202, Lactobacillus helveticus 92201, and Lactobacillus delbrueckii ssp. bulgaricus 92059, showed the highest activities following growth in milk. All three strains degraded α- and β-casein, but did not hydrolyse κ-casein. HPLC analysis of skim milk fermentation revealed increasing amounts of peptides after 5 and 10 h with Lb. d. ssp. bulgaricus 92059. Hydrolysates obtained with Lb. d. ssp. lactis 92202 and Lb. d. ssp. bulgaricus 92059 revealed the highest angiotensin-converting enzyme-inhibitory effect. The effect was dose dependent. Almost no effect (<10%) was seen for Lb. helveticus 92201. For Lb. d. ssp. bulgaricus 92059, maximal inhibition of approx. 65% was reached after 25 h of fermentation. In an in vitro assay measuring potential immunomodulation, hydrolysates of the three strains yielded anti-inflammatory activities in the presence of TNF-α. However, the effects were more pronounced at lower hydrolysate concentrations. In the absence of TNF-α, slight pro-inflammatory effects were observed. The hydrolysate of Lb. d. ssp. bulgaricus 92059, when purified by means of solid-phase extraction, exhibited pro-inflammatory activity. Sour whey containing Lb. d. ssp. bulgaricus 92059 cells showed pro-inflammatory activity while cell-free sour whey was clearly anti-inflammatory. In the purified hydrolysate, 20 different α- and β-casein (CN)-derived peptides could be identified by LC-MS. Most peptides originated from the central and C-terminal regions of β-casein. Peptide length was between 9 (β-CN(f 59-67)) and 22 amino acids (β-CN(f 117-138)).
在筛选具有蛋白水解活性的乳酸菌时，发现三株乳杆菌，即 Lactobacillus delbrueckii ssp. lactis 92202、Lactobacillus helveticus 92201 和 Lactobacillus delbrueckii ssp. bulgaricus 92059，在牛奶中生长后表现出最高的活性。这三株菌都能降解α-和β-酪蛋白，但不能水解κ-酪蛋白。用 HPLC 分析脱脂奶发酵发现，随着 Lb. d. ssp. bulgaricus 92059 的作用，在 5 和 10 小时后，多肽的含量逐渐增加。用 Lb. d. ssp. lactis 92202 和 Lb. d. ssp. bulgaricus 92059 获得的水解产物显示出最高的血管紧张素转化酶抑制作用。这种作用是剂量依赖的。用 Lb. helveticus 92201 几乎没有效果（<10%）。对于 Lb. d. ssp. bulgaricus 92059，发酵 25 小时后达到最大抑制作用，约 65%。在一项测量潜在免疫调节作用的体外试验中，三种菌株的水解产物在 TNF-α存在的情况下产生抗炎活性。然而，在较低的水解产物浓度下，效果更为明显。在没有 TNF-α的情况下，观察到轻微的促炎作用。通过固相萃取对 Lb. d. ssp. bulgaricus 92059 的水解产物进行纯化后，显示出促炎活性。含有 Lb. d. ssp. bulgaricus 92059 细胞的酸乳显示出促炎活性，而无细胞酸乳则明显具有抗炎作用。在纯化的水解产物中，通过 LC-MS 可鉴定出 20 种不同的α-和β-酪蛋白（CN）衍生肽。大多数肽来源于β-酪蛋白的中央和 C 末端区域。肽的长度在 9（β-CN(f 59-67)）和 22 个氨基酸（β-CN(f 117-138)）之间。
