In this project, the phenotypic diversity (antibiotic resistance, inhibition, pigmentation, and hyphal structure) of antibiotic-producing streptomycetes isolated from varying soils is examined. As a team, students (junior- and senior-level undergraduates) prepare a dilution series and perform a plate count on their soil. As individuals, students identify, purify, and make spore suspensions of the four best antibiotic-producing streptomycete isolates from their soil sample. They challenge their streptomycete isolates against antibiotic-containing discs, gram-positive and gram-negative bacteria, and other streptomycetes isolated from their soil. As a team, students prepare short oral reports, collect data, and present their experimental results.