ABSTRACT Tyramine is generated by decarboxylation of tyrosine through tyrosine decarboxylase enzyme produced by bacteria in fermented food including different cheese types. In the current study, 27 cheese samples were collected from local markets in Alexandria, Egypt, and analyzed for the prevalence of tyramine-producing bacteria by PCR using degenerate primers (DEC5/DEC3). A probiotic, Lactobacillus rhamnosus LGG® was evaluated for its ability to inhibit tyramine production in these isolates by High-Performance Liquid Chromatography (HPLC) analysis. A total of 31 strains harbored tyrosine decarboxylase gene with the identification of novel tyramine-producing strains including Macrococcus caseolyticus, Bacillus vallismortis, Bacillus cereus, Staphylococcus sciuri, and Staphylococcus pasteuri. L. rhamnosus LGG® suppressed the growth of 81% of the studied tyraminogenic strains. It completely inhibited the tyramine production in B. vallismortis with a decline of 99.4% and 50% in tyramine production in S. saprophyticus, and S. pasteuri, respectively. These results indicated the promising application of L. rhamnosus to reduce tyramine production in cheese products, a goal that has been regarded as a challenge by manufacturers.

中文翻译：

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从埃及亚历山大收集的奶酪样品中鼠李糖乳杆菌 (LGG®) 的抗酪胺潜力

摘要 酪胺是由发酵食品中的细菌产生的酪氨酸脱羧酶通过酪氨酸脱羧产生的，包括不同类型的奶酪。在当前的研究中，从埃及亚历山大的当地市场收集了 27 份奶酪样品，并使用简并引物 (DEC5/DEC3) 通过 PCR 分析了产酪胺细菌的流行情况。通过高效液相色谱 (HPLC) 分析评估了益生菌鼠李糖乳杆菌 LGG® 抑制这些分离物中酪胺生成的能力。共有31株酪氨酸脱羧酶基因被鉴定出产酪胺的新型菌株，包括干酪巨球菌、巴氏芽孢杆菌、蜡样芽孢杆菌、金黄色葡萄球菌和巴氏葡萄球菌。L。鼠李糖 LGG® 抑制了 81% 所研究的酪氨酸生成菌株的生长。它完全抑制了 B. vallismortis 中酪胺的产生，使 S. saprophyticus 和 S. pasteuri 中的酪胺产生分别下降了 99.4% 和 50%。这些结果表明鼠李糖乳杆菌在减少奶酪产品中酪胺产量方面的应用前景广阔，这一目标已被制造商视为挑战。