Tsigkrimani Markella, Panagiotarea Konstantina, Paramithiotis Spiros, Bosnea Loulouda, Pappa Eleni, Drosinos Eleftherios H, Skandamis Panagiotis N, Mataragas Marios
Department of Food Science and Human Nutrition, Agricultural University of Athens, 75 Iera Odos St., 11855 Athens, Greece.
Department of Dairy Research, Institute of Technology of Agricultural Products, Hellenic Agricultural Organization "DIMITRA", 3 Ethnikis Antistaseos St., 45221 Ioannina, Greece.
Foods. 2022 Feb 3;11(3):459. doi: 10.3390/foods11030459.
The aim of the present study was to examine 189 LAB strains belonging to the species , , , , , , , , , and isolated form sheep milk, Feta and Kefalograviera cheeses at different ripening stages, for their technological compatibility with dairy products manufacturing, their activities that may compromise safety of the dairy products as well as their capacity to survive in the human gastrointestinal tract. For that purpose, milk acidification and coagulation capacity, caseinolytic, lipolytic, hemolytic, gelatinolytic, and bile salt hydrolase activity, production of exopolysaccharides, antimicrobial compounds, and biogenic amines, as well as acid and bile salt tolerance and antibiotic susceptibility were examined. The faster acidifying strains were DRD 2658 and DRD 2657 that reduced the pH value of skim milk, within 6 h to 5.97 and 5.92, respectively. Strains able to perform weak caseinolysis were detected in all species assessed. On the contrary, lipolytic activity, production of exopolysaccharides, amino acid decarboxylation, hemolytic, gelatinase, and bile salt hydrolase activity were not detected. Variable susceptibility to the antibiotics examined was detected among LAB strains. However, in the majority of the cases, resistance was evident. None of the strains assessed, managed to survive to exposure at pH value 1. On the contrary, 25.9 and 88.9% of the strains survived after exposure at pH values 2 and 3, respectively; the reduction of the population was larger in the first case. The strains survived well after exposure to bile salts. The strain-dependent character of the properties examined was verified. Many strains, belonging to different species, have presented very interesting properties; however, further examination is needed before their potential use as starter or adjunct cultures.
本研究的目的是检测从不同成熟阶段的绵羊奶、费塔奶酪和凯法洛格里维拉奶酪中分离出的189株属于 、 、 、 、 、 、 、 、 和 种的乳酸菌菌株，评估它们与乳制品制造的技术兼容性、可能影响乳制品安全的活性以及在人类胃肠道中的存活能力。为此，检测了乳酸酸化和凝固能力、酪蛋白分解、脂肪分解、溶血、明胶分解和胆汁盐水解酶活性、胞外多糖、抗菌化合物和生物胺的产生，以及酸和胆汁盐耐受性和抗生素敏感性。酸化速度较快的菌株是DRD 2658和DRD 2657，它们分别在6小时内将脱脂乳的pH值降至5.97和5.92。在所评估的所有物种中均检测到能够进行弱酪蛋白分解的菌株。相反，未检测到脂肪分解活性、胞外多糖产生、氨基酸脱羧、溶血、明胶酶和胆汁盐水解酶活性。在乳酸菌菌株中检测到对所检测抗生素的不同敏感性。然而，在大多数情况下，耐药性很明显。所评估的菌株中没有一株能够在pH值为1的环境中存活。相反，分别有25.9%和88.9%的菌株在pH值为2和3的环境中存活后存活下来；在第一种情况下，菌数减少幅度更大。这些菌株在接触胆汁盐后存活良好。所检测特性的菌株依赖性特征得到了验证。许多属于不同物种的菌株表现出非常有趣的特性；然而，在它们作为发酵剂或辅助培养物潜在应用之前，还需要进一步研究。
