Bifidobacterium faecale sp. nov., isolated from human faeces

Abstract

A novel strain, designated strain CU3-7T, 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 CU3-7T was phylogenetically affiliated with members of the genus Bifidobacterium . Strain CU3-7T showed the highest level of sequence similarity with Bifidobacterium adolescentis KCTC 3216T (98.4 %), followed by Bifidobacterium ruminantium KCTC 3425T (97.9 %). Analysis of hsp60 sequences showed that strain CU3-7T was closely related to B. adolescentis KCTC 3216T (94.0 %) and B. ruminantium KCTC 3425T (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 3425T and 14.9 % with B. adolescentis KCTC 3216T. Fructose-6-phosphate phosphoketolase activity was detected. The predominant cellular fatty acids were C16 : 0 (27.7 %), C18 : 1ω9c (27.4 %) and C18 : 1ω9c dimethylacetate (15.5 %). The DNA G+C content was 58.6 mol%. On the basis of polyphasic taxonomy, strain CU3-7T 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 17904T = JCM 19861T).