Novel vitamin B12-producing Enterococcus spp. and preliminary in vitro evaluation of probiotic potentials
Novel vitamin B12-producing Enterococcus spp. and preliminary in vitro evaluation of probiotic potentials
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新型产维生素 B-12 肠球菌属。
DOI：
10.1007/s00253-017-8373-7
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发表时间：
2017-08-01
影响因子：
5
通讯作者：
Chen, Jieyan V.
中科院分区：
文献类型：
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作者：
Li, Ping;Gu, Qing;Chen, Jieyan V.
维生素 B-12 是人体重要代谢过程所需的必需营养素。产生维生素 B-12 的乳酸菌 (LAB) 目前因其普遍被认为是安全的 (GRAS) 状态而受到越来越多的关注。最近的大多数研究都集中在乳酸菌上，而对产生 B-12 的肠球菌却知之甚少。在本研究中，从婴儿粪便中分离出的五种肠球菌菌株被鉴定为维生素 B-12 生产者。其中，屎肠球菌LZ86的B-12产量最高（499.8+/-83.7μg/L），并且利用反相高效液相（RP-HPLC）色谱图将LZ86中的B-12化合物鉴定为具有生物活性的腺苷钴胺素。我们检查了屎肠球菌 LZ86 的基本益生菌和安全特性，发现它能够在恶劣的环境条件（高温、低温、乙醇和渗透压）下生存，耐受胃酸（pH 2.0，3 小时）和胆盐（0.3%），并粘附在 Caco-2 细胞上。我们还表明，屎肠球菌 LZ86 缺乏可转移的抗生素耐药性和潜在的毒力因子。我们在此首次报道了一种产 B-12 的屎肠球菌菌株 LZ86，该菌株具有理想的益生菌特性，可作为食品工业中维生素 B-12 强化的良好候选者。
Vitamin B-12 is an essential nutrient required for crucial metabolic processes in humans. Vitamin B-12-producing lactic acid bacteria (LAB) have been attracting increased attentions currently because of the generally recognized as safe (GRAS) status. Most of recent studies focused on Lactobacillus, and little is known about B-12-producing Enterococcus. In the present study, five Enterococcus strains isolated from infant feces were identified as vitamin B-12 producers. Among them, Enterococcus faecium LZ86 had the highest B-12 production (499.8 +/- 83.7 mu g/L), and the B-12 compound from LZ86 was identified as the biological active adenosylcobalamin, using reversed phase high-performance liquid (RP-HPLC) chromatogram. We examined basic probiotic and safety properties of E. faecium LZ86 and found that it was able to survive harsh environmental conditions (hot temperature, cold temperature, ethanol and osmotic stresses), tolerate gastric acid (pH 2.0, 3 h) and bile salts (0.3%), and adhere to Caco-2 cells. We also showed that E. faecium LZ86 is devoid of transferable antibiotic resistance and potential virulence factors. Together, here we report a B-12-producing E. faecium strain LZ86 firstly, which has desirable probiotic properties and may serve as a good candidate for vitamin B-12 fortification in food industry.