Fig. 2.

Phylogenomics of β-galactosidases. Neighbour-joining tree based on the alignment of 137 putative β-galactosidases identified across 34 members of infant-derived bifidobacterial (sub)species. A red circle highlights the genes used for experimental assessment in this study, while blue and orange squares identify those genes of which involvement in the assimilation of GOS and HMOs have been reported in literature. Circles on the phylogenetic tree highlight nodes with bootstrap values above 90% and dark blue circles identify the 14 phylogenetic groups defined by our analysis