Department of Biotechnology, School of Life Sciences, Pondicherry University, Puducherry, 605014, India.
Department of Biotechnology, School of Life Sciences, Pondicherry University, Puducherry, 605014, India.
Microb Pathog. 2022 Nov;172:105783. doi: 10.1016/j.micpath.2022.105783. Epub 2022 Sep 20.
The goal of this study was to determine the unique characteristics of Enterococcus faecium MC-5, a probiotic bacteria isolated from the intestine of a fish, Cyprinus carpio specularis, collected from Dal Lake in Srinagar, Kashmir, India. For this, the important valuable probiotic attributes, some functional properties, and safety assessments were analyzed in-vitro for the strain MC-5. The strain E. faecium MC-5 exhibited high resistance to low pH, high bile salt, lysozyme, and phenol. The strain MC-5 showed excellent auto- and co-aggregation properties and displayed remarkable hydrophobicity towards various tested hydrocarbons which suggested that the strain possesses venerable adhesion properties. Apart from these, the cell-free supernatant (CFS) of strain MC-5 exhibited phenomenal antimicrobial activity against the tested pathogens. A scanning electron microscope (SEM) image revealed strain MC-5 finely adhered to human colon adenocarcinoma cells (HCT-15 cells). The strain MC-5 showed high bile salt hydrolase activity and excellent cholesterol removal ability of 70.27%. The intact cells of strain MC-5 also showed strong DPPH scavenging activity. The EPS produced by E. faecium MC-5 inhibited the adhesion of Listeria monocytogenes, Staphylococcus aureus, and Salmonella enterica on HCT-15 cells with maximum inhibition rates of 41.82, 40.34, and 55.51%, respectively for displacement assay, which was higher as compared to exclusion (26.06, 26.11, and 39.23%) and competition assays (30.06, 26.7, and 41.20%). Strain MC-5 did not exhibit hemolysis and was also found susceptible to vancomycin and other clinically important antibiotics. When evaluating all the results from the present study, it is propounded that strain MC-5 has enviable probiotic characteristics and thus can be used as bio-protective cultures and/or bio-shield in food and pharmaceutical industries.
本研究的目的是确定从印度克什米尔斯利那加达勒湖采集的镜鲤肠道中分离出的益生菌细菌屎肠球菌 MC-5 的独特特征。为此，对菌株 MC-5 的重要有价值的益生菌特性、一些功能特性和安全性评估进行了体外分析。屎肠球菌 MC-5 表现出对低 pH、高胆汁盐、溶菌酶和苯酚的高抗性。该菌株 MC-5 表现出出色的自动和共聚集特性，并对各种测试的烃类表现出显著的疏水性，这表明该菌株具有良好的粘附特性。除此之外，菌株 MC-5 的无细胞上清液（CFS）对测试病原体表现出显著的抗菌活性。扫描电子显微镜（SEM）图像显示，菌株 MC-5 精细地附着在人结肠腺癌细胞（HCT-15 细胞）上。该菌株 MC-5 表现出高胆汁盐水解酶活性和出色的胆固醇去除能力，为 70.27%。完整的菌株 MC-5 细胞也表现出强烈的 DPPH 清除活性。屎肠球菌 MC-5 产生的 EPS 抑制了李斯特菌、金黄色葡萄球菌和肠炎沙门氏菌在 HCT-15 细胞上的粘附，在置换试验中，其最大抑制率分别为 41.82%、40.34%和 55.51%，高于排除（26.06%、26.11%和 39.23%）和竞争试验（30.06%、26.7%和 41.20%）。菌株 MC-5 不表现溶血，并且对万古霉素和其他临床重要抗生素也敏感。当评估本研究的所有结果时，认为菌株 MC-5 具有令人羡慕的益生菌特性，因此可用于食品和制药行业的生物保护培养物和/或生物屏蔽。
