Use of different nitrogen sources by the edible ectomycorrhizal mushroom Cantharellus cibarius.

The growth of three strains of Cantharellus cibarius on liquid media containing ammonium, nitrate and bovine serum albumin (BSA) in different combinations was determined. The most readily utilisable source of N was ammonium. BSA utilisation was limited compared with media containing ammonium. Growth on nitrate was also poor, suggesting a limited capacity of C. cibarius to metabolise this nitrogen source. There was some indication of considerable intraspecific variation within C. cibarius in the utilisation of nitrogen sources. Possible links between atmospheric nitrogen deposition and the observed decrease of sporocarp formation by C. cibarius in Europe are discussed. We highlight the potential ecological significance of bacteria associated with C. cibarius which may circumvent the need for fungal extracellular enzymes to access complex nitrogen sources.