Protein fingerprinting as a complementary analysis to classical phenotyping for the identification of lactic acid bacteria from Tenerife cheese

A total of 125 lactic acid bacteria (LAB) from the genera Lactococcus, Lactobacillus and Leuconostoc isolated from Tenerife cheese were identified by both classical phenotypic and protein fingerprinting methods. Classical identification revealed the presence of 11 different species and subspecies of LAB. Lactobacilli and leuconostocs identification was easy to achieve with the API 50 CH system. By contrast, the identification of lactococci was difficult due to the heterogeneous and atypical profiles displayed by our strains. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) of cell-free extracts (protein fingerprinting) has proved to be an efficient identification method for LAB from Tenerife cheese. It generated complex and stable patterns that are easy to interpret and compare with those of the reference strains. SDS-PAGE analysis could discriminate well between the 8 different species and subspecies of LAB. However, the assignment of LAB strains to one of the Leuconostoc mesenteroides subspecies required, in addition to protein fingerprinting, the performance of two biochemical tests. When results of both identification methods were compared, 23% of Tenerife cheese LAB isolates turned out to have been misclassified by the classical technique. lactic acid bacteria / cheese / identification / protein fingerprinting Rsum -L'empreinte digitale des protines comme analyse complmentaire aux mthodes phnotypiques classiques pour l'identification des bactries lactiques du fromage de Tenerife. Cent-vingt-cinq bactries lactiques (LAB) des genres Lactococcus, Lactobacillus et Leuconostoc, isoles partir du fromage de Tenerife, ont t identifies par les mthodes phnotypiques classiques et par la mthode d'empreinte digitale des protines. Par identification classique, 11 espces et sousespces diffrentes des LAB ont t mises en vidence. Les lactobacilles et leuconostocs ont t facilement identifis l'aide du systme API 50 CH. Par contre, l'identification des lactocoques s'est rvle difficile en raison des profils htrognes et atypiques des souches. L'lectrophorse en SDS polyacrylamide (SDS-PAGE) de l'extrait cellulaire (l'empreinte digitale des protines) s'est