A Comparison by the Use of Gel Electrophoresis of Soluble Protein Components and Esterase Enzymes of some Group D Streptococci

SURMMARY Soluble cell constituents of strains of Streptococcus faecalis, S. faecium and S. durans were studied by electrophoresis in polyaery lamide gels followed by staining the gel to reveal the patterns of separated proteins and esterase enzymes. The patterns of proteins and of esterases found in S. faecalis differed from those in S. faecium and S. durans. Strains of S. faecalis differing in serotype and variety showed a very similar series of proteins, some differences in patterns of esterases were found, but similar patterns occurred in strains differing in type and variety. The major protein bands of S. faecium and S. durans differed in mobility from the major proteins of S. faecalis; different strains of S. faecium and S. durans showed some differences in other protein bands. Esterase activity of S. faecium and S. durans was weaker than that of S. faecalis, and in the case of most strains only faint esterase bands were detected. A strain of S. faecium which gave protein and esterase patterns different from those of the remaining strains, differed also in showing motility.