Exopeptidase profiles of bifidobacteria.

The exopeptidase activities of five different strains of bifidobacteria occurring habitually in healthy human intestinal canal were measured on 61 synthetic substrates. The cluster analysis, based on the results, indicates that four strains, with the exception of Bifidobacterium adolescentis a M101-4, have similar exopeptidase profiles. All CFE from these five strains contained at least three kinds of aminopeptidases (aminopeptidase with broad substrate specificity, aminopeptidase hydrolyzing selectively X-Pro type and aminopeptidase hydrolyzing selectively Pro-X type) and carboxypeptidase.