Potential of fungi in the discovery of novel, low-molecular weight pharmaceuticals.

Publisher Summary This chapter focuses on the potential of fungi in the discovery of novel, low-molecular weight pharmaceuticals. Although the estimated 3000 to 4000 known fungal secondary metabolites have been isolated after screening hundreds of thousands of fungal cultures, possibly not more than 5000 to 7000 taxonomic species have been studied in this respect, the latter being the number of fungal species maintained in culture collections throughout the world and representing, therefore, fungal species that can be readily grown in axenic culture. There are well-known fungal groups that resist artificial cultivation and have been largely excluded from industrial screenings. These include obligate biotrophic fungi mycorrhiza, as well as arthropod-associated groups such as the whole class of the Laboulbeniales with 1730 known species, but there are also many saprobes that will not grow in the laboratory, probably because of unknown but essential triggers of spore germination. Investigation of underexploited, possibly extreme habitats in conjunction with specific isolation techniques should provide one of the key answers to industrial exploitation of fungal diversity, which might be tantamount to chemical diversity. Strains found in outstanding habitats or missed in traditional isolation procedures could well be producers of metabolites that have been unknown thus far.