List of <i>Bifidobacterium</i> strains, with additional information on the source of isolation.

For each strain, the relative levels of AI-2 production (means +/- SEM) in the diluted supernatant are given compared to AI-2 levels produced by the biosensor itself ( = 100%). Data presented are mean +/- SEM from triplicate experiments. In addition, the results for the PCR assay with primers directed against luxS are shown. (* +, PCR positive result, -, PCR negative result; ** T, type strain of the species).