Plating media contains enzyme substrates (ES) used to detect enzyme activity associated with a target organism and that include a binding motif (BM) that serves to bind detectable enzymes (DE) (also called marker enzymes in this disclosure). A signalogenic substructure (SG) produces detectable signals and an enzyme labile group (ELG) is labile to the action of a marker enzyme and it typically includes the binding motif. The enzyme labile group links to the signalogenic substructure via a labile bond (LB) which is cleaved by the action of the marker enzyme separating the signalogenic substructure and the enzyme labile group. In some embodiments a linker is inserted between the signalogenic substructure and the enzyme labile group. Presence of the enzyme and thus the organism is detected by presence of a fluorogenic, precipitate that can be detected in single colonies.
