Figure 2. Using common metabolite signals as a species-specific classification index.

Common metabolite signals were extracted from 5 reference strains of each species (B. subtilis, T. xiamenensis and T. mobilis). Then each LC-MS profile in the database is searched for the presence of these signals, and the percentage found was plotted as a data point. The data points are sorted by taxonomical level: different strains of the same species (Species), different species of the same genus (Genus), and different genera (Others). The results indicate that the number of found “species-specific signals” correlates with the taxonomical similarity, and that one can potentially use these “species-specific signals” as a phenotypic classification index, e.g., percentages above the red line indicate strains from the same species.