Differentiation of Lactobacillus sake and Lact. curvatus isolated from naturally fermented Greek dry salami by SDS-PAGE of whole-cell proteins

J. SAMELIS, E. TSAKALIDOU, J. METAXOPOULOS AND G. KALANTZOPOULOS. 1995. To confirm the phenotypic characterization of 169 predominant sausage isolates of the Lactobacillus sake/curvatus group, SDS-polyacrylamide gel electrophoresis (SDS-PAGE) of whole-cell proteins of 29 representative strains was undertaken. The results of the electrophoretic analysis indicated that each species yielded a specific protein profile, identical to the respective type strain. It was shown that all melibiose-positive isolates belonged to Lact. sake , whether or not they were arginine- and maltose-positive, whereas all melibiose- and arginine-negative isolates were assigned to Lact. curvatus. A group which phenotypically appeared to lie between Lact. sake and Lact. curvatus , on the basis of arginine (+), melibiose (-) and maltose (-) reactions, was shown to be more closely related to Lact. sake. The SDS-PAGE method was valuable in distinguishing between species, but did not allow further differentiation of Lact. curvatus or Lact. sake strains displaying high heterogeneity in secondary physiological and biochemical properties.