Students work individually to selectively enrich, isolate, purify, and characterize microorganisms from the soil belonging to 2 of the groups (the actinomycetes and the fungi) well-known for their ability to produce compounds belonging to the world of secondary metabolites. The secondary metabolites encompass any materials that are not part of primary metabolism, and we know many of these products such as pigments, odors, and most importantly antibiotics. The students evaluate isolates for their ability to produce antibiotics as part of a group project. Zones of inhibition for the various isolates are measured against a panel of test organisms. This laboratory is an excellent starting point for discussions of antibiotic discovery and use, microbial ecology, diversity, and antibiotic resistance. Group discussion and a formal report are used to assess the project.