Streptomyces is a genus of soil-dwelling, filamentous bacteria famous as nature’s antibiotic factory: most natural antibiotics, including streptomycin from S. griseus and neomycin from S. fradiae, were discovered in this genus. Some species are used in veterinary medicine for treating bacterial infections in cattle, sheep, swine, and poultry, with residues that can persist in muscle, eggs, and milk, so withdrawal periods are enforced and parenteral use in food animals is restricted in regions such as the EU. In food plants they are mainly an environmental microbe, notable for the earthy, musty odour compounds they can produce.