Bifidobacterium mongoliense sp. nov., from airag, a traditional fermented mare's milk product from Mongolia

1 Yakult Central Institute for Microbiological Research, 1796 Yaho, Kunitachi, Tokyo 186-8650, Japan 2 Mongolian State University of Agriculture, Zaisan-53, MSUA Ulaanbaatar 210153, Mongolia Correspondence Koichi Watanabe koichi-watanabe{at}yakult.co.jp Two novel micro-organisms, designated strains YIT 10443 T and YIT 10738, were isolated from airag, a traditional fermented mare's milk from Mongolia. The two strains were Gram-positive-staining, non-motile, asporogenous, catalase-negative, facultatively anaerobic rods of various shapes. Comparative analyses of 16S rRNA and ClpC ATPase ( clpC ) gene sequences and the presence of fructose-6-phosphate phosphoketolase (F6PPK) demonstrated that the novel strains were members of the genus Bifidobacterium . On the basis of 16S rRNA gene sequence similarity, the type strains of Bifidobacterium minimum (96.6 %) and Bifidobacterium psychraerophilum (95.7 %) were the closest neighbours of the novel strains, and DNA–DNA reassociation values with these strains were found to be lower than 15 %. The phenotypic and genotypic features demonstrated that the two strains represent a single, novel Bifidobacterium species, for which the name Bifidobacterium mongoliense sp. nov. is proposed. The type strain is YIT 10443 T (=JCM 15461 T =DSM 21395 T ). Abbreviations: F6PPK, fructose-6-phosphate phosphoketolase; LAB, lactic acid bacteria; RAPD, randomly amplified polymorphic DNA The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA gene sequences of strains YIT 10443 T , YIT 10738, B. minimum YIT 4097 T and B. psychraerophilum YIT 11814 T are AB433856 , AB433857 , AB437350 and AB437351 , respectively, and those for the clpC gene sequences of strains YIT 10443 T , YIT 10738, B. minimum YIT 4097 T and B. psychraerophilum YIT 11814 T are AB433858 –AB433861, respectively. RAPD-PCR fingerprints and scanning electron micrographs of the novel strains and a maximum-likelihood 16S rRNA gene sequence-based tree are available as supplementary material with the online version of this paper.