Abstract：
Due to the reports describing virulent and multidrug resistant enterococci, their use has become a topic of controversy despite most of them being safe and commonly used in traditionally fermented foods worldwide. We have characterized Enterococcus lactis SF68, a probiotic strain approved by the European Food Safety Authority (EFSA) for use in food and feed, and find that it has a remarkable potential in food fermentations. Genome analysis revealed the potential of SF68 to metabolize a multitude of carbohydrates, including lactose and sucrose, which was substantiated experimentally. Bacteriocin biosynthesis clusters were identified and SF68 was found to display a strong inhibitory effect against Listeria monocytogenes. Fermentation-wise, E. lactis SF68 was remarkably like Lactococcus lactis and displayed a clear mixed-acid shift on slowly fermented sugars. SF68 could produce the butter aroma compounds, acetoin and diacetyl, the production of which was enhanced under aerated conditions in a strain deficient in lactate dehydrogenase activity. Overall, E. lactis SF68 was found to be versatile, with a broad carbohydrate utilization capacity, a capacity for producing bacteriocins, and an ability to grow at elevated temperatures. This is key to eliminating pathogenic and spoilage microorganisms that are frequently associated with fermented foods.
摘要：
由于描述毒性和多重耐药肠球菌的报告，它们的使用已经成为一个有争议的话题，尽管它们中的大多数都是安全的，并且普遍用于世界范围内的传统发酵食品。我们已经表征了乳酸肠球菌SF68，这是欧洲食品安全局（EFSA）批准用于食品和饲料的益生菌菌株，并发现它在食物发酵中具有显着的潜力。基因组分析揭示了SF68代谢多种碳水化合物的潜力，包括乳糖和蔗糖,实验证实了这一点。鉴定了细菌素生物合成簇，发现SF68对单核细胞增生李斯特菌具有很强的抑制作用。发酵明智，乳酸大肠杆菌SF68与乳酸乳球菌非常相似，并且在缓慢发酵的糖上显示出明显的混合酸变化。SF68可以产生黄油香气化合物，乙酰和二乙酰，在缺乏乳酸脱氢酶活性的菌株中，在充气条件下其产量得到提高。总的来说,大肠杆菌SF68被发现是通用的，具有广泛的碳水化合物利用能力，生产细菌素的能力，以及在高温下生长的能力。这是消除经常与发酵食品相关的致病和腐败微生物的关键。
