Biotechnological substances in lichens

Abstract Lichens are symbiotic organisms composed of a fungal partner (mycobiont) in association with one or more photosynthetic partners (photobiont) that can be green algae, cyanobacteria, or both. Due to their specificities, lichens can live in conditions where neither the alga nor the fungus could live independently, and very often they dwell in some of the most extreme environments such as arctic tundra, deserts, or rocky habitats. Specific conditions of life are the reasons for the production of numerous secondary metabolites protecting lichens from various negative biological and physical influences. Lichens and their secondary metabolites exert a wide variety of biological actions including antibiotic, antioxidant, antimycotic, anticancer, antiviral, antiinflammatory, analgesic, antipyretic, and neuroprotective effects. Since there is a lot of interest in new products of natural origin that do not cause side effects, this chapter represents lichens as very interesting natural source of bioactive substances that have great biotechnological application.