Genotypic and phenotypic diversity of Lactobacillus delbrueckii subsp. lactis strains of dairy origin.

摘要: Eighty-nine strains of Lactobacillus delbrueckii subsp. lactis isolated from Italian hard and semi-hard cheeses artisan starter cultures were characterised by phenotypic genotypic methods. Phenotypic diversity was evaluated studying biochemical characteristics (i.e. acidifying peptidase activities) technological interest. Genotypic evidenced RAPD-PCR pulsed field gel electrophoresis (PFGE). characterisation indicated a wide variability the activity within Lact. lactis. Although data variable, it allowed us to evidence groups with different properties, especially in terms acidification intensity. Concerning activity, showed homogeneously high x-prolil-dipeptidil-aminopeptidase considerable but more heterogeneous lysil-aminopeptidase activity. The increased resolution obtained use two molecular typing techniques, i.e. PFGE, widen level strain heterogeneity. Technological ecological pressures are determinant selecting sub-populations which functional cheese technologies.