发酵乳中动物双歧杆菌乳亚种分离及鉴定

Isolation and Identification of Bifidobacterium animails subsp. lactis in Fermented Milk Products

摘要:

采用改良MRS培养基从蒙牛冠益乳酸奶中选择性分离得到2种乳酸菌, 表型特征检测初步确定目标菌株BB-12, 该菌株符合双歧杆菌属特征描述。通过Biolog微生物自动鉴定系统鉴定、16S rDNA序列分析、atpD基因序列分析, 多相鉴定表明: 菌株BB-12为动物双歧杆菌乳亚种(Bifidobacterium animalis subsp. lactis)。系统发育学分析表明: atpD基因序列比16S rDNA序列在动物双歧杆菌亚种水平鉴定上有更好的分辨率。

Abstract:

Two strains were selectively isolated from the sample of Mengniu fermented milk product on modified MRS medium. Strain BB-12 was selectived by morphology observation, it was consistent with the characteristics of Bifidobacterium sp.. On the basis of polyphasic approach: morphology, physiology and molecular properties, it was evident that the strain BB-12 belonged to Bifidobacterium animalis subsp. lactis. Analysis of 16S rDNA sequences (GenBank accession No. GU116483) and atpD gene sequences (GenBank accession No. GU116482) revealed that the latter had clear separation of two subspecies while the former was not possible since their sequences displayed at least 99.1% homology.