The concentrated extract from W. anomalus 1F1 culture was analyzed by size exclusion chromatography and eluted fractions were assayed for killing activity against the reference C. lusitaniae strain. In agreement with the immunoblot data, the results indicated the elution of active Wa1F1-KT in fractions 34–39 of the size exclusion chromatogram (Figure 3), corresponding to the highest molecular mass separation zone.