Protein profiles from intact cells as a tool in Bifidobacterium characteristics.

In this study sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) profiles were analysed and differences were confirmed by a unweighted pair group method with arithmetic average (UPGMA) analysis between bifidobacterial species, such as B. infanis ATCC1567, B. bifidum Bb-12, B. longum KN29, B. catenulatum KD14, and B. animalis BI30. Two dimensional electrophoresis separation profiles were compared, and the most characteristic spots were characterized by liquid chromatography-tandem mass spectrometry (LC-MS/MS). We propose proteins extracted from intact cells as an additional trait for bifidobacteria characterization, together with molecular techniques, which can be used to analyze bacterial protein polymorphism and to distinguish among species.