The study aimed to optimize culture conditions and nutrient requirements for theproduction of secondary metabolites by the cultured mycobiont Lobaria spathulata. This species proved to be an excellent model system for such studies, as the complete chemosyndromefound in the natural lichen thallus was repeatedly formed in the cultured mycobiont with differentiated, aerial mycelia. Nutrient media containing the disaccharide, sucrose, were found to favour both rapid growth and the production of typical lichen substances. Higher proportions of the secondary compounds were detected in the developing mycobiont than in mature lichen thalli.
