Zhejiang University, College of Biosystem Engineering and Food Science, 268 Kaixuan Road, Hangzhou, China.
J Sci Food Agric. 2010 Jun;90(8):1340-6. doi: 10.1002/jsfa.3942.
Currently, bifidobacteria are recognised as one of the most important bacteria used as probiotics, which promote human health. However, their commercial application has been limited by their anaerobic nature. The purpose of this study was to select an oxygen, acid and bile resistant strain of bifidobacterium for use as a new probiotic.
A total of 10 strains of bifidobacteria from different sources were analysed for their relative bacterial growth ratio (RBGR) in different oxygen concentrations. Three strains with high RBGR values were selected and their survival rates in acid environment and bile salt conditions were investigated in vitro. One strain showed high tolerance to low pH, giving a survival rate of 84% at pH 2 after 4 h incubation, and high tolerance to bile, more than 90% after 4.5 h incubation at 0.01 g mL(-1) bile concentration. This strain was identified as Bifidobacterium animalis subsp. lactis strain Qq08 based on polyphasic taxonomy approaches, such as phenotype analysis and 16S rRNA and 16S to 23S internally transcribed spacer sequence analyses.
We isolated an aerotolerant bifidobacterium and identified it as Bifidobacterium animalis subsp. lactis Qq08. This strain has characteristics more favourable than the commercial probiotic strain, Bifidobacterium lactis Bb12.
目前，双歧杆菌被认为是最重要的益生菌之一，能够促进人体健康。然而，由于其厌氧特性，其商业应用受到限制。本研究旨在筛选出一种耐氧、耐酸、耐胆盐的双歧杆菌菌株，用作新型益生菌。
分析了来自不同来源的 10 株双歧杆菌在不同氧浓度下的相对细菌生长比（RBGR）。选择了 3 株 RBGR 值较高的菌株，并在体外研究了它们在酸性环境和胆汁盐条件下的存活率。其中一株对低 pH 值具有较高的耐受性，在 pH 2 下孵育 4 小时后的存活率为 84%，对胆汁的耐受性也较高，在 0.01 g mL(-1)胆汁浓度下孵育 4.5 小时后的存活率超过 90%。该菌株根据多相分类学方法，如表型分析和 16S rRNA 及 16S 到 23S 内部转录间隔区序列分析，被鉴定为乳双歧杆菌亚种 lactis 菌株 Qq08。
我们分离出一株耐氧双歧杆菌，并将其鉴定为乳双歧杆菌亚种 lactis Qq08。该菌株的特性优于商业益生菌菌株乳双歧杆菌 Bb12。
