Bifidobacterium aquikefiri sp. nov., isolated from water kefir

Abstract

A novel <i>Bifidobacterium</i>, strain LMG 28769^T, was isolated from a household water kefir fermentation process. Cells were Gram-stain-positive, non-motile, non-spore-forming, catalase-negative, oxidase-negative and facultatively anaerobic short rods. Analysis of its 16S rRNA gene sequence revealed <i>Bifidobacterium crudilactis</i> and <i>Bifidobacterium psychraerophilum</i> (97.4 and 97.1 % similarity towards the respective type strain sequences) as nearest phylogenetic neighbours. Its assignment to the genus <i>Bifidobacterium</i> was confirmed by the presence of fructose 6-phosphate phosphoketolase activity. Analysis of the <i>hsp60</i> gene sequence revealed very low similarity with nucleotide sequences in the NCBI nucleotide database. The genotypic and phenotypic analyses allowed the differentiation of strain LMG 28769^T from all recognized <i>Bifidobacterium</i> species. Strain LMG 28769^T ( = CCUG 67145^T = R 54638^T) therefore represents a novel species, for which the name <i>Bifidobacterium aquikefiri</i> sp. nov. is proposed.