This study was focused on screening the most frequently occurring enterocin (Ents) genes in faecal enterococci from the Pannon White breed of rabbits, in which this parameter never has been tested. Enterococci tested were Ent genes absent, except Enterococcus faecium EF9a, which possessed genes for four Ents. Strains produced a high amount of lactic acid (1.25 ± 0.055 mmol/L, on average) and sufficiently tolerate bile. Inhibition activity of crude bacteriocin substance—partially purified (Ent, CE EF9a)—was tested against altogether 53 indicator strains. The growth of 38 strains of different staphylococcal species was not inhibited. However, the growth of fifteen other Gram-positive indicators was inhibited with inhibition activity ranged from 100 to 12,800 AU/mL. Listeria monocytogenes LM 7562 was the most susceptible to CE EF9a treatment (12,800 AU/mL). Molecular mass of CE EF9a ranged between 3000 and 10,000 Da. After heat treatment at different temperatures and time, CE EF9a was active with the inhibition activity 12,800 AU/mL. After storage of CE EF9a at different conditions, it was active even after 2-month storage at room temperature (200 AU/mL against LM 7562 strain). Inhibition activity of CE EF9a after 2-month storage at 4 °C was 1600 AU/mL and the most stable was CE EF9a at − 20 °C; the activity 12,800 AU/mL was kept still after 2 months. It indicates a small, thermostable substance; however, in further detail, purification analysis is necessary.

中文翻译：

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Pannon 白种兔肠球菌中肠球菌素结构基因的筛选。

本研究的重点是筛选 Pannon White 家兔粪便肠球菌中最常见的肠毒素 (Ents) 基因，但从未测试过该参数。测试的肠球菌不存在Ent基因，但屎肠球菌EF9a除外，它具有四个Ent 的基因。菌株产生大量乳酸（平均为 1.25 ± 0.055 mmol/L）并充分耐受胆汁。粗制细菌素物质——部分纯化（Ent，CE EF9a）——对总共 53 种指示菌株的抑制活性进行了测试。38 株不同葡萄球菌的生长没有受到抑制。然而，15 种其他革兰氏阳性指标的生长受到抑制，抑制活性范围为 100 至 12,800 AU/mL。单核细胞增生李斯特菌LM 7562 对 CE EF9a 处理最敏感（12,800 AU/mL）。CE EF9a 的分子量介于 3000 和 10,000 Da 之间。在不同温度和时间的热处理后，CE EF9a 具有活性，抑制活性为 12,800 AU/mL。CE EF9a 在不同条件下储存后，即使在室温下储存 2 个月（200 AU/mL 对 LM 7562 菌株）后，它仍具有活性。CE EF9a 在 4 °C 下储存 2 个月后的抑制活性为 1600 AU/mL，最稳定的是 CE EF9a 在 − 20 °C 下；2 个月后，活性 12,800 AU/mL 保持不变。它表示一种小的、耐热的物质；然而，更详细地，纯化分析是必要的。