Interrelationship of Phosphate Nutrition, Nitrogen Metabolism, and Accumulation of Key Secondary Metabolites in Saprophytic Cultures of Psilocybe cubensis, Psilocybe cyanescens, and Panaeolus campanulatus

Abstract

The three basidiomycetes were grown on rotary shakers in four nutrient media containing various amounts of phosphate to determine the relative effect of this nutrient on the trichloroacetic acid-soluble and -insoluble nitrogen metabolites and to detect possible correlation between the fungal free amino acid pool (soluble nitrogen) and accumulation of characteristic hydroxytryptamine derivatives. The species were selected to represent different patterns of metabolism in fruiting bodies and vegetative mycelia. Vegetative mycelium of P. cubensis was characterized by a relatively high soluble nitrogen component and by the capacity to accumulate psilocybin and psilocin under selected conditions. The closely related P. cyanescens was less responsive to variations in phosphate nutrient and lacked the capacity to accumulate appreciable quantities of soluble nitrogenous compounds or detectable quantities of key tryptamines. P. campanulatus grown in phosphate-rich media appeared to have an adequate free amino acid pool and to excrete some exocellular nitrogen metabolites during longer incubation periods; no 5-hydroxytryptamine derivatives were detected in cultures of this fungus.