Centre of Biosciences of the Slovak Academy of Sciences, Institute of Animal Physiology, Šoltésovej 4-6, 040 01 Košice, Slovakia.
Int J Environ Res Public Health. 2020 Dec 18;17(24):9504. doi: 10.3390/ijerph17249504.
Enterococci are lactic acid bacteria. Most of them can adapt well to the food system due to their salt and acid-tolerance. Moreover, many enterococcal species have been found to produce antimicrobial substances of proteinaceous character, i.e., bacteriocins/enterocins. In this study, EM ML2/2 with bacteriocinogenic potential was identified in Slovak raw goat milk. This strain demonstrated inhibition activity against up to 36% of Gram-positive indicator bacteria, and in concentrated form the bacteriocin substance (pH 6.3) showed the highest inhibition activity (1600 AU/mL) against the principal indicator strain EA5. Semi-purified substance (SPS) EM ML2/2 produced inhibition activity up to 3200 AU/mL. Concentrated bacteriocin substance and SPS maintained active (inhibition activity up to 100 AU/mL) for three months under -20 °C storage conditions. The strain showed susceptible antibiotic profile, and it did not form biofilm. No production of damaging enzymes was noted. It was nonhemolytic, as well as DNase, and gelatinase-negative. It grew well in skim milk, and it was salt and acid-tolerant. The bacteriocin potential of species isolated from Slovak raw goat milk has not previously been detected, so this is an original contribution which may stimulate addtitional research and application studies.
肠球菌是乳酸细菌。由于其耐盐和耐酸特性,大多数肠球菌能够很好地适应食品体系。此外,许多肠球菌物种已被发现产生具有蛋白质性质的抗菌物质,即细菌素/肠球菌素。在本研究中,从斯洛伐克生羊奶中鉴定出具有细菌素生成潜力的 EM ML2/2 菌株。该菌株对多达 36%的革兰氏阳性指示菌表现出抑制活性,而浓缩形式的细菌素物质(pH 6.3)对主要指示菌株 EA5 表现出最高的抑制活性(1600 AU/mL)。半纯化物质(SPS)EM ML2/2 产生的抑制活性高达 3200 AU/mL。浓缩细菌素物质和 SPS 在 -20°C 的储存条件下可保持活性(抑制活性高达 100 AU/mL)达三个月。该菌株表现出敏感的抗生素谱,不形成生物膜。未发现产生破坏性酶。它是非溶血的,DNase 和明胶酶阴性。它在脱脂乳中生长良好,并且耐盐和耐酸。从斯洛伐克生羊奶中分离出的 种的细菌素潜力以前未被检测到,因此这是一项原创性贡献,可能会激发更多的研究和应用研究。