Bioactive Microbial Secondary Metabolites, better nowadays defined as Specialized Metabolites

Microbial specialized (secondary) metabolites are bioactive natural molecules that confer specific ecological and/or physiological advantages to producer microbes. Starting with the “Golden Age of Antibiotics”, the discovery of specialized metabolites has expanded to yield antibacterial, antifungal, anticancer, and immunosuppressive drugs, principally synthetized by fungi, actinobacteria, and other “rare” bacterial taxa. In response to the increasing demand for novel bioactive molecules and the declining rate of their isolation, the implementation of new discovery strategies has become essential, such as genome mining and multi-omics, with the aim of unlocking cryptic chemical diversity. These approaches offer unparalleled potential to revitalize the pharmaceutical pipeline and discover nextgeneration therapeutics.