Three Gram-stain-positive, non-spore-forming, microaerophilic and fructose-6-phosphate phosphoketolase positive strains were isolated from a faecal sample of an adult subject of the emperor tamarin (Saguinus imperator). Given that the isolates revealed identical BOX PCR profiles, strain TRI 5T was selected as a representative and characterized further. Comparative analysis of 16S rRNA gene sequence similarity revealed that strain TRI 5T was closely related to Bifidobacterium saguini DSM 23967T (96.4 %) and to Bifidobacterium longum subsp. longum ATCC 15708 (96.2 %). Multilocus sequence analyses of five housekeeping genes showed the close phylogenetic relatedness of this strain to Bifidobacterium breve DSM 20213T (hsp60 94.1 %), Bifidobacterium saguini DSM 23967T (clpC 91 %), Bifidobacterium avesanii DSM 100685T (dnaG 80.3 %), Bifidobacterium longumsubsp. infantis ATCC 15697T (dnaJ 85.3 %) and Bifidobacterium longumsubsp. longum ATCC 15708 (rpoB 93 %), respectively. The peptidoglycan type was A3β, with an interpeptide bridge comprising l-Orn (Lys) - l-Ser - l-Ala - l-Thr - l-Ala. The DNA G+C content of strain TRI 5T was 60.9 mol%. Based on the data provided, strain TRI 5T represents a novel species of the genus Bifidobacterium for which the name Bifidobacteriumcallitrichidarum sp. nov. is proposed. The type strain is TRI 5T (=DSM 103152T=JCM 31790T).
Keywords: Bifidobacterium callitrichidarum sp. nov; Bifidobacterium spp.; Saguinus imperator; emperor tamarin; novel species.