TABLE 20.1 Representative Sources of Antibiotics Microorganism Antibiotic Gram-Positive Rods Bacillus subtilis Bacitracin Bacillus polymyxa Polymyxin Actinomycetes Streptomyces nodosus Amphotericin B Streptomyces venezuelae Chloramphenicol Streptomyces aureofaciens Chlortetracycline and tetracycline Streptomyces erythraeus Erythromycin Streptomyces fradiae Neomycin Streptomyces griseus Streptomycin Micromonospora purpureae Gentamicin Fungi Cephalosporium spp. Cephalothin Penicillium griseofulvum Griseofulvin Penicillium notatum Penicillin Table 20.1Table 20.1