Metagenomic identification, purification and characterisation of the Bifidobacterium adolescentis BgaC β-galactosidase.

Members of the human gut microbiota use glycoside hydrolase (GH) enzymes, such as β-galactosidases, to forage on host mucin glycans and dietary fibres. A human faecal metagenomic fosmid library was constructed and functionally screened to identify novel β-galactosidases. Out of the 16,000 clones screened, 30 β-galactosidase-positive clones were identified.