Endolichenic fungi from common lichens as new sources for valuable bio-active compounds

Lichens are known to produce bio-active compounds. However, their natural slow growth limited progress in researching lead compounds from lichens for drug development. In recent years, a rare group of fungi were found to grow in the lichens, identified as endolichenic fungi (EF). The discovery of this group of fungi is relatively new but has attracted notable attention attributed to their phar macological potential (antimicrobial, antiviral, antioxidant, and antitumor). Interestingly, these endolichenic fungi produce bio-active compounds that may be distinct from those produced by their host lichens. With an estimate of 20,000 known lichens reported worldwide, there are tremendous opportunities to discover valuable endolichenic fungi. Thus, the aim of present chapter is to provide an overview on the progress and advances made in the research of endolichenic fungi. Also, it discusses on the emerging biotechnological approaches to explore endolichenic fungi.