Abstract The aim of this study was to characterize 29 Leuconostoc mesenteroides isolates obtained from a brewing process in order to determine their potential contributions to this process and the product. In order to achieve this aim different enzymatic activities, the exopolysaccharide (EPS) production, the antagonistic activity, the beer spoilage ability and the production of lactic acid and diacetyl in beer, were assessed. Ln. mesenteroides isolates showed weak acidifying activity, and only 28% of them produced decreases in pH higher than 0.5 units after a 24 h period of incubation. The isolates were also scarcely proteolytic and did not produce EPS. Results from enzymatic activity assay showed that some of the isolates produced β-galactosidase and α- and β-glucosidases while none produced β-glucuronidase. All the isolates inhibited the growth of both Escherichia coli and Staphylococcus aureus, although none of them inhibited Pediococcus acidilactici. When Lactobacillus brevis was used as an indicator, 44.8% of the isolates showed antagonistic activity. The beer-spoilage ability assay showed that only 5 of the 29 isolates were able to grow in beer but none of them harboured horA or horC genes. However, the growth of these isolates in beer did not produce an excess of D-lactic acid or diacetyl. These findings show that the presence of any of the characterized isolates during the brewing process or in the bottled beer would not have a negative impact. On the contrary, the findings reveal interesting and potentially beneficial effects.

中文翻译：

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酿造过程中的肠系膜明串珠菌：一个有争议的角色

摘要 本研究的目的是表征从酿造过程中获得的 29 种肠系膜明串珠菌分离物，以确定它们对这一过程和产品的潜在贡献。为了实现这一目标，对不同的酶活性、胞外多糖 (EPS) 产量、拮抗活性、啤酒腐败能力以及啤酒中乳酸和双乙酰的产量进行了评估。LN。肠系膜分离株表现出弱酸化活性，在培养 24 小时后，只有 28% 的菌株的 pH 值降低超过 0.5 个单位。分离株也几乎不进行蛋白水解并且不产生EPS。酶活性测定结果表明，一些分离物产生β-半乳糖苷酶和α-和β-葡萄糖苷酶，而没有产生β-葡萄糖醛酸酶。所有的分离株都能抑制大肠杆菌和金黄色葡萄球菌的生长，尽管它们都没有抑制乳酸片球菌。当以短乳杆菌为指标时，44.8%的分离株表现出拮抗活性。啤酒腐败能力测定表明，29 个分离株中只有 5 个能够在啤酒中生长，但没有一个含有 horA 或 horC 基因。然而，这些分离物在啤酒中的生长不会产生过量的 D-乳酸或双乙酰。这些发现表明，在酿造过程中或瓶装啤酒中存在任何特征分离株不会产生负面影响。相反，研究结果揭示了有趣且潜在的有益效果。当以短乳杆菌为指标时，44.8%的分离株表现出拮抗活性。啤酒腐败能力测定表明，29 个分离株中只有 5 个能够在啤酒中生长，但没有一个含有 horA 或 horC 基因。然而，这些分离物在啤酒中的生长不会产生过量的 D-乳酸或双乙酰。这些发现表明，在酿造过程中或瓶装啤酒中存在任何特征分离株不会产生负面影响。相反，研究结果揭示了有趣且潜在的有益效果。当以短乳杆菌为指标时，44.8%的分离株表现出拮抗活性。啤酒腐败能力测定表明，29 个分离株中只有 5 个能够在啤酒中生长，但没有一个含有 horA 或 horC 基因。然而，这些分离物在啤酒中的生长不会产生过量的 D-乳酸或双乙酰。这些发现表明，在酿造过程中或瓶装啤酒中存在任何特征分离株不会产生负面影响。相反，研究结果揭示了有趣且潜在的有益效果。这些分离物在啤酒中的生长不会产生过量的 D-乳酸或双乙酰。这些发现表明，在酿造过程中或瓶装啤酒中存在任何特征分离株不会产生负面影响。相反，研究结果揭示了有趣且潜在的有益效果。这些分离物在啤酒中的生长不会产生过量的 D-乳酸或双乙酰。这些发现表明，在酿造过程中或瓶装啤酒中存在任何特征分离株不会产生负面影响。相反，研究结果揭示了有趣且潜在的有益效果。