Antibiotics are substances produced by microorganisms that kill
or inhibit the growth of other microorganisms and are typical
secondary metabolites (Section 15.2). Most antibiotics used in
human and veterinary medicine are produced by filamentous
fungi or bacteria of the Actinobacteria group ( Section 18.6).
Table 15.3 lists the most important antibiotics produced by largescale
industrial fermentations today.