A novel bifidobacteria (designated S053-2^T) was isolated from the gut of honeybee (Apis mellifera). Strain S053-2^T was characterized using a polyphasic taxonomic approach. The result of 16S rRNA gene sequence analysis indicated that strain S053-2^T was phylogenetically related to the type strains of Bifidobacterium asteroides, Bifidobacterium indicum, Bifidobacterium actinocoloniiforme, Bifidobacterium xylocopae, Bifidobacterium coryneforme, Bifidobacterium apousia, Bifidobacterium choladohabitans and Bifidobacterium polysaccharolyticum, and had 95.5-99.7 % 16S rRNA gene sequence similarities. Based on the 16S rRNA gene sequence analysis, strain S053-2^T was most closely related to the type strain of B. asteroides, having 99.7 % 16S rRNA gene sequence similarity. Strain S053-2^T had relatively low (91.6-95.7 %) pheS, atpA, clpC, dnaG, fusA, glnA, glyS, hsp60, argS, pyrG and recA sequence similarities to the type strain of B. asteroides. Strain S053-2^T had 94.5-95.3% atpA, clpC, dnaG, dnaK and pyrG sequence similarities to the type strain of B. apousia. The phylogenomic tree indicated that strain S053-2^T belonged to the B. asteroides group, and was most closely related to the type strains of B. asteroides, B. apousia, B. choladohabitans and B. polysaccharolyticum, and distantly related to type strains of other phylogenetically related species in the B. asteroides group. Strain S053-2^T shared the highest average nucleotide identity (ANI, 93.8 %), digital DNA-DNA hybridization (dDDH, 52.4 %) and average amino acid identity (AAI, 95.6%) values with B. apousia W8102^T. Strain S053-2^T shared 91.1 % ANI, 41.9 % dDDH and 92.5 % AAI values with B. asteroides DSM 20089^T. Acid production from l-arabinose, d-xylose, d-mannose, amygdalin, cellobiose, maltose, melibiose, sucrose, raffinose, gentiobiose and l-fucose, and activity of esterase lipase (C8) and α-fucosidase could differentiate strain S053-2^T from B. asteroides DSM 20089^T. Acid production from d-mannose, maltose, sucrose, melezitose and gentiobiose, and activity of α-fucosidase could differentiate strain S053-2^T from B. apousia W8102^T. Based upon the data obtained in the present study, a novel species, Bifidobacterium mizhiense sp. nov., is proposed, and the type strain is S053-2^T (=JCM 34710^T=CCTCC AB 2021129^T).

Hong Xia Zhang

Publications