Bifidobacterium faecale sp nov., isolated from human faeces

Abstract

A novel strain, designated strain CU3-7(T), was isolated from faeces of a two-week-old baby. The isolate was Gram-staining-positive, anaerobic and rod-shaped. Results from 16S rRNA gene sequence analysis revealed that strain CU3-7(T) was phylogenetically affiliated with members of the genus Bifidobacterium. Strain CU3-7(T) showed the highest level of sequence similarity with Bifidobacterium adolescentis KCTC 3216(T) (98.4 %), followed by Bifidobacterium ruminantium KCTC 3425(T) (97.9%). Analysis of hsp60 sequences showed that strain CU3-7(T) was closely related to B. adolescentis KCTC 3216(T) (94.0%) and B. ruminantium KCTC 3425(T) (92.5 %). The DNA-DNA hybridization values with the closely related strains were all below the cut-off value for species delineation, 17.0% with B. ruminantium KCTC 3425(T) and 14.9% with B. adolescentis KCTC 3216(T). Fructose-6-phosphate phosphoketolase activity was detected. The predominant cellular fatty acids were C-16:0 (27.7%), C-18:1 omega 9c (27.4%) and C-18:1 omega 9c dimethylacetate (15.5%). The DNA G+C content was 58.6 mol%. On the basis of polyphasic taxonomy, strain CU3-7(T) should be classified as the type strain of a novel species within the genus Bifidobacterium, for which the name Bifidobacterium faecale sp. nov. is proposed (=KACC 17904(T)=JCM 19861(T)).