Application of polyacrylamide gel electrophoresis and capillary gel electrophoresis to the analysis of Lactobacillus delbrueckii whole-cell proteins

Whole-cell. protein profiles of different strains of Lactobacillus delbruec kii isolated from dairy products were studied by capillary gel electrophore sis and PAGE. The high similarity among Lactobacillus delbrueckii profiles, including those of the type strains, confirmed the close phylogenetic rela tionship among the subspecies. However, some remarkable differences in band s of 36, 38, 70, 94, and >115 kDa allowed us to distinguish Lactobacillus d elbrueckii ssp. bulgaricus from Lactobacillus delbrueckii ssp. lactis. Cluster analysis of the PAGE protein profile and capillary gel electrophore sis electropherograms grouped Lactobacillus delbrueckii ssp. bulgaricus in a cluster and Lactobacillus delbrueckii ssp. lactis and Lactobacillus delbr ueckii ssp. delbrueckii in another one. The second cluster showed a close r elationship between all of the Lactobacillus delbrueckii ssp. lactis strain s. In conclusion, the analysis of whole-cell protein profiles by PAGE and capi llary gel electrophoresis proved to be useful to resolve the taxonomic stat us of the Lactobacillus delbrueckii subspecies.