Characterization of the Different Forms of Phosphorus in the Mycelium of the Ectomycorrhizal Fungus, Hebeloma Cylindrosporum, Cultivated in Pure Culture

Summary The ectomycorrhizal fungus, Hebeloma cylindrosporum, was grown in pure culture at different phosphorus concentrations, with or without shaking. Phosphorus fractions were separated by a modified Mudd, Yoshida & Koite (1958) method. Acid‐soluble and acid‐insoluble phosphorus precipitated with barium acetate were identified by thin layer chromatography. In pure culture. Hebeloma cylindrosporum stores very little polyphosphate (4 to 9% of total P) and amounts are unrelated to the concentration of external phosphorus. Most of the phosphorus is stored as orthophosphate. Internal orthophosphate is well correlated with external orthophosphate and is readily utilized to form DNA and phospholipid. Internal soluble organic phosphorus can also be mobilized but to a lesser extent.