The largest antibiotic-producing genus:
Streptomyces is the largest antibiotic-producing genus in the microbial world so far. It is a filamentous bacterium and certain species are noted for the production of antibiotics.
Some examples of antibiotics produced by this genus include:
Streptomyces griseus - streptomycin
Streptomyces aureofaciens -Chlortetracycline
Streptomyces rimosus - oxytetracycline
Streptomyces erythraeus - erythromycin
Streptomyces venezuelae - chloramphenicol